An image forming apparatus includes a charging member configured to charge a photoreceptor, a power supply configured to provide charging power to the charging member, a measurement unit configured to measure a current provided to the charging member, and a controller configured to search for a current saturation point of the charging member using the current value measured by the measurement unit in a state in which fixed direct current (DC) power and varied alternating current (AC) power are supplied to the charging member, and control the power supply to perform a charging operation with only DC power corresponding to the searched current saturation point.

1. Field
Apparatuses and methods consistent with the present disclosure relate to an image forming apparatus and a method for controlling charging thereof, and more particularly, to an image forming apparatus for performing charging using a magnitude of a current provided to a photoreceptor without measuring a surface potential of the photoreceptor, and a method for controlling charging thereof.
2. Related Art
An image forming apparatus refers to an apparatus for printing print data generated by a print control terminal device such as a computer to print paper. Examples of the image forming apparatus may include a photocopier, a printer, a facsimile, or a multi-function peripheral (MFP) having functions of a photocopier, a printer, and a facsimile, complexly implemented therein as a single apparatus.
Recently, laser print type image forming apparatuses have been commonly used, and a printing operation of a laser print type image forming apparatus includes charging, exposing, developing, transferring, and fusing processes.
In the charging process of the printing operation, a contact charging scheme of charging a photoreceptor by bringing a roller type charging member into contact with the photoreceptor is widely used. The contact charging scheme for charging a photoreceptor may include a direct current (DC) charging scheme of applying only a DC voltage and an AC+DC charging scheme of overlapping a DC voltage and an alternating current (AC) voltage and applying the overlapped voltage to a charging member.
Here, the DC charging scheme is a method of performing a charging operation only with DC power, which causes less damage to a surface of a photoreceptor to lengthen lifespan of the photoreceptor and generates less discharge products, compared with the AC+DC charging scheme. However, a surface potential of the photoreceptor formed due to DC charging is not uniform, compared with that printed and formed through AC+DC charging.
The AC+DC charging scheme is a method of performing a charging operation using AC power together with application of DC power, obtaining high uniformity of a surface potential of a photoreceptor, and when AC having a voltage with a sufficiently high peak value is applied to a specific DC voltage, the photoreceptor is charged to have the same surface potential as that of the DC voltage. However, a large amount of discharge occurring between a charging member and the photoreceptor damages a surface of the photoreceptor to degrade lifespan of the photoreceptor.
Meanwhile, a DC charging scheme is widely used in terms of lengthening lifespan of a photoreceptor. However, it is very complicate and difficult to determine a DC voltage to be applied in consideration of an environment, resistance of a charging member, and lifespan of a photoreceptor to form a desired surface potential of the photoreceptor.
In a recent DC charging scheme, a separate sensor for measuring a surface potential of a photoreceptor may be used, but it is also very complicate and difficult to use a separate sensor to measure a surface potential of a photoreceptor amid the trend in which image forming apparatuses are increasingly reduced in size.

Image forming apparatus and method for controlling charging thereof


A sintered silicon carbide ceramic body preferably produced from a uniform mixture comprising from about 82 percent to about 99.4 percent by weight silicon carbide, from about 0.5 percent to about 10 percent by weight of a nitrogen containing aluminum compound and from about 0.1 to about 8 percent of a rare earth oxide, both reacted with oxygen, wherein said sintered ceramic body has a density greater than 90% percent of theoretical and a fracture toughness, as measured by a single edge notched beam test, of more than 7 MPam.sup.1/2 and method of making the same.

This invention relates in general to sintered ceramic bodies. In one respect, this invention is directed to polycrystalline sintered bodies based on silicon carbide which exhibit high fracture toughness and relatively lower brittleness and good chipping resistance. In a further aspect, the invention is directed to a process for the preparation of sintered bodies and the use of sintering additives to promote the formation of a transient liquid phase during the densification of silicon carbide.
Structural ceramic materials which retain their strengths to temperatures on the order of 1400.degree. C. to 1500.degree. C. are desirable for their application in high temperature environments including, for example, those encountered in automotive applications such as gas turbines, diesel superchargers, stirling engines and the like. Currently silicon carbide and silicon nitride are the leading contending materials for use in gas turbine engines. "SiAlON", an acronym derived from the chemical symbols of the constituents silicon, aluminum, oxygen and nitrogen, is a group of materials which are somewhat related to silicon nitride and which generally exhibit higher toughness, but lower strengths than silicon nitride, and higher strengths, but lower oxidation and creep resistance than silicon carbide.
Silicon nitride (Si.sub.3 N.sub.4) is typically densified, aided by a liquid glassy phase, at temperatures ranging from 1500.degree. C. to 1850.degree. C. for times which can be as short as 30 minutes. The presence of a liquid phase is critical to the process since it allows alpha phase silicon nitride to be converted into beta phase silicon nitride. The initially present alpha phase silicon nitride transforms into beta phase silicon nitride. This process produces an acicular microstructure (as distinguished from an equiaxed microstructure) which can provide good fracture toughness. Typical sintering aids used to densify Si.sub.3 N.sub.4 include MgO, Y.sub.2 O.sub.3, Al.sub.2 O.sub.3, ZrO.sub.2, CeO.sub.2, and CaO. These oxides and others react with silica present on the surface of the silicon nitride to form a glassy amorphous (noncrystalline) phase at temperatures below 1850.degree. C. This glassy phase tends to inhibit creep resistance at elevated temperatures of 800.degree. C. and above. Decomposition of Si.sub.3 N.sub.4 begins as low as 1000.degree. C. and becomes progressively greater as temperature is increased, becoming quite excessive at temperatures greater than 1700.degree. C. Although Si.sub.3 N.sub.4 materials can have a greater strength and toughness than conventional SiC and therefore can be more resistant to catastrophic failure, SiC has higher hardness and is therefore preferred in wear applications. Also, SiC has a higher resistance to creep which is beneficial in heat engine applications. Creep is that property of any material wherein deformation occurs at elevated temperatures either with an applied load or otherwise.
The chemical and physical properties of silicon carbide make it an excellent material for high temperature structural applications, such as gas turbine engine components. These desirable properties include excellent oxidation resistance and corrosion resistance, relatively high thermal conductivity compared to other ceramics, relatively low thermal expansion coefficient compared to metals, relatively high resistance to thermal shock and relatively high strength at elevated temperatures. For example, SiC is stronger than the nickel superalloys at temperatures above 1000.degree. C. and has better creep and oxidation resistance, as well as being potentially less expensive. Another advantage is that the theoretical density of silicon carbide, being 3.21 g/cm.sup.3, is less than half that of the superalloys. On the other hand, other characteristics of known bodies of essentially pure sintered silicon carbide, particularly those produced by known pressureless sintering processes, are considered undesirable, including inability to be electrical discharge machined (EDM) at an acceptable rate due to generally poor electrical conductivity (high electrical resistivity), high sensitivity of the microstructure to variations in sintering conditions, grain growth upon extended or repeated exposure to relatively high temperatures above about 1900.degree. C., and low (relative to SiAlON or silicon nitride) fracture toughness.
The sintering of silicon carbide, in the absence of applied mechanical pressure ("pressureless sintering"), has been accomplished using various sintering aids. Those sintering aids include carbon (C), boron (B) and compounds thereof, e.g., boron carbide (B.sub.4 C), and aluminum (Al), and compounds thereof, e.g., alumina (Al.sub.2 O.sub.3), individually and/or in combination. Such sintering aids have been used to obtain essentially nearly single crystalline phase silicon carbide with relatively high densities, for example, 97% of theoretical density or greater. "Sinter-active SiC powders", those having high specific surface areas of about 1 M.sup.2 /g to 100 m.sup.2 /g, and an average nominal diameter of about one micron or less, with some powders being less than 0.5 microns in average nominal diameter, are considered necessary to achieve relatively high densities, for example, as is described in U.S. Pat. No. 4,312,954.
The sintering of conventional silicon carbide (using boron and carbon as sintering additives) typically takes place at temperatures of at least 1900.degree. C. but below 2500.degree. C., and typically in a range of about 2100.degree. C. to 2250.degree. C., and is accomplished principally by solid state diffusion without the occurrence of a liquid phase; this is known as solid state sintering. Pressureless sintering allows for the economically viable commercial fabrication of complex shapes, and so it is desirable for silicon carbide particles to be densified without applied mechanical pressure, as well as at reduced temperatures, due to the fact that high temperatures are known to promote grain growth and a consequent deterioration in physical properties.
A drawback of conventional silicon carbide ceramic material is its brittleness, which, for example, causes the edges of a sintered body to be easily chipped in handling, resulting in poor production yields. Another drawback is sensitivity to the introduction of internal flaws during the production process, causing low strength values, rendering the resultant material undependable in respect to the application of localized high stresses during use. The known sintered silicon carbides, including the conventional materials, do not exhibit high enough toughness to overcome the loss of strength occasioned by such flaws, even when such flaws are relatively minor.
Silicon carbide densification by the pressureless sintering method, with sintering additives, has been the subject of various patents including the SiC--B--C system (U.S. Pat. Nos. 4,179,299; 4,004,934; 4,526,734; 4,692,418; 4,124,667; and 3,649,342) and the SiC--Al--C system, (U.S. Pat. No. 4,692,418 to Boecker, et al, 1979 and U.S. Pat. No. 4,230,497 to Schwetz, et al).
The SiC--B--C system provides different properties depending upon the amount of sintering additives and the particular production process used. These properties allow various applications of silicon carbide from armor tiles to electrical heating elements. However, the extremely high hardness and the transgranular fracture mode, inherent in such conventional silicon carbide, produce relatively low fracture toughness. The typical fracture toughness data for SiC--B--C system is between 4 and 5 MPam.sup.1/2 measured by the single edge notched beam (SENB) test method as is well known to those with skill in the art.
The SiC--Al--C combination is another well-studied system which also offers high density, good high temperature strengths and thermal stability. This material also exhibits a transgranular fracture mode at room temperature and intergranular fracture mode at elevated temperature. Oxidation resistance is reported to be better than that of the SiC--B--C system. Fracture toughness for this system is typically within the range of about 4 and 6 MPam.sup.1/2.
Silicon carbide has been sintered to high density, using rare earth oxides as additives, usually resulting in high strength. Omori, et al. U.S. Pat. Nos. 4,502,983, 4,564,490, and 4,569,921 disclose the use of rare earth oxides to promote solid state diffusion sintering. These inventions require the use of SiC of submicron size and typically result in surfaces having higher concentrations of rare earth oxides. High bend strength, between 59.6 ksi and 127.7 ksi are reported, however, it is not known whether or not these strengths are based on a three-point test method (which has been generally used in Japan and which generally gives values which are 30% to 50% higher than a four-point test) or based on the four-point bend test method which is more universally accepted and considered more representative and more reflective of accurate true bend strength. The Saito U.S. Pat. No. 4,681,861 teaches the use of Y.sub.2 O.sub.3 --Al.sub.2 O.sub.3 --Cr.sub.2 O.sub.3 as sintering additives and reports very dense silicon carbide bodies. A bend strength of 42.6-66.7 ksi (by the four-point bend test method, but using 4 mm.times.3 mm.times.35 mm test pieces in accord with Japanese standard JIS R-1601) and indentation fracture toughnesses of 5-6 MPam.sup.1/2 were also reported, and the product had good corrosion resistance at high temperatures in contact with molten steel. Virkar, et al. U.S. patent application Ser. No. 778,251, which is disclosed in U.S. Pat. No. 4,829,027 to Cutler et al., discloses a method for densifying mixtures containing Si--C--Al--O--N into a solid state diffusion sintered body, as taught by U.S. Pat. No. 4,141,740, using a liquid phase provided by the carbothermal reduction of alumina (Al.sub.2 O.sub.3) to produce "SiCAlON". Such a technique is not believed to result in ceramic material exhibiting high fracture toughness.
Japanese published patent application ("Kokai") to Nagano, Application No. 51384/59 filed Mar. 16, 1984 and Publication No. 195057/60 published Oct. 3, 1985 discloses a system wherein Al.sub.2 O.sub.3, CeO.sub.2 and SiO.sub.2, in separate and distinct powder forms are mixed with SiC powder, formed with a temporary binder and sintered within a temperature range of 1800.degree. C. to 1950.degree. C. This prior art application teaches firstly that it is absolutely necessary to add SiO.sub.2 as a separate and distinct powder, secondly, that the sintered body will decompose at sintering temperatures above 1950.degree. C. causing the loss of shape of that body and a substantial reduction in bend strength and, thirdly, that the mechanism is entirely liquid phase. This prior art application, insofar as the sintering additives are concerned, also teaches that AlN can be substituted for Al.sub.2 O.sub.3 and that Y.sub.2 O.sub.3 can be substituted for CeO.sub.2.

Silicon carbide bodies having high toughness and fracture resistance and method of making same


A gate electrode is formed above an n-type well including an n-type threshold voltage adjustment region, ions of p-type impurity are implanted with a low acceleration energy to form extension regions in the n-type well on both sides of the gate electrode, side wall spacers are formed on the side walls of the gate electrode, ions of p-type impurity are implanted with a small dose causing substantially no abnormal tailing in the gate electrode and with a relatively high acceleration energy to form p-type source/drain regions deeper than the threshold adjustment region, ions of atoms are implanted into the semiconductor substrate to change the upper parts of the gate electrode and the source/drain regions to amorphous state, ions of p-type impurity are implanted with a large dose to form high-concentration parts in the source/drain regions, and the impurities introduced by the ion implantation are activated.

(A) Field of the Invention
The present invention relates to a semiconductor device manufacture method, and more particularly to a method of manufacturing a semiconductor device having very fine transistors.
(B) Related Art
Semiconductor integrated circuit devices are at the stage of higher integration degree and operation speed. Constituent elements of a semiconductor integrated circuit device, MOS transistors, are becoming very fine in accordance with the scaling rules. The gate insulating film becomes thin and the gate length becomes short. The height of the gate electrode is limited.
As the gate length becomes short, carriers can punch through from the source to drain and the short channel effect appears. In order to prevent the short channel effect, extension regions having shallow junctions are formed in intermediate areas between the source/drain regions.
If element isolation is formed by local oxidation of silicon (LOCOS), bird's beaks are formed gradually thickening the oxide film so that an area of an active region and hence an integration degree are limited. In place of LOCOS, shallow trench isolation (STI) has been adopted by which a trench is formed in a substrate and an insulating film is buried in the trench. With STI, the roughness of a substrate surface can be reduced.
As the gate insulating film is thinned, a phenomenon appears which cannot be neglected: impurities in the gate electrode penetrate through the gate insulating film and invade the channel region. As impurities enter the channel region, a threshold voltage of the channel region varies. Among other ions, boron (B) ions implanted into the gate electrode of a p-channel transistor are likely to penetrate through the gate electrode. Impurity penetration is influenced by ion implantation into the gate electrode and the conditions of subsequent heat treatments. Impurity penetration can be mitigated by executing impurity ion implantation into the gate electrode at a low acceleration energy and executing activation annealing in a very short time.
In general, Ion implantation into the gate electrode and ion implantation into the source/drain regions are carried out simualtaneously. At a low acceleration energy, the source/drain regions become shallow. Well forming ion implantation and threshold voltage adjusting ion implantation are performed for an active region. If the source/drain junctions are shallow, these junctions are positioned in the region having an impurity concentration raised by the threshold voltage adjusting ion implantation, so that a junction capacitance increases. An increase in capacitance lowers the operation speed. Further, a shallow junction increases leak current.
FIG. 4A shows an example of the structure of an n-channel MOS transistor. If the conductivity type is reversed, the structure is of a p-channel MOS transistor. An element isolation trench is formed in a surface layer of a silicon substrate 101, and an insulator is buried in the trench to form an element isolation region 102. In an active region defined by the element isolation region 102, p-type impurities are implanted to form a p-type well 103. In a p-type well surface layer, p-type impurity ions are implanted to form a channel region 104 having a higher impurity concentration and adjusted threshold voltage.
The surface of the silicon substrate is thermally oxidized to form a gate insulating film 105, and a poly-silicon layer 106 is deposited on the gate insulating film. The poly-silicon layer and underlying gate insulating film are patterned to form a gate electrode. By using the gate electrode as a mask, n-type impurity ions are implanted to form n-type extension regions 107. A silicon oxide layer is deposited covering the gate electrode. The silicon oxide layer is etched back to form side wall spacers 108 on the gate electrode side walls.
Impurity ions of the n-type are again implanted to form deep source/drain regions 109 and also implanted into the gate electrode at a sufficient impurity concentration. A metal layer of Co or Ni is deposited on the substrate surface by sputtering and form silicide layers 110 on the surfaces of the source/drain regions and on the surface of the gate electrode.
An insulating layer 112 of silicon oxide or the like is deposited covering the gate electrode, and contact holes are formed through the insulating layer. Conductive plugs 114 are embedded in the contact holes.
In the STI forming process, a silicon nitride layer having an underlying silicon oxide layer is used as a stopper layer for chemical mechanical polishing (CMP). In a process of removing the silicon nitride layer and silicon oxide layer, the shoulder 120 of STI is etched slightly. A concave portion 122 is therefore formed at the STI edge in contact with the active region. An existence of this concave portion swells the silicide layer 110 downward, and also the conductive plug 114 may extend lower than the active region surface. If the effective thickness of the source/drain regions becomes thin, leak current is likely to flow through the source/drain junctions.
FIG. 4B shows another structure formed at a lower ion implantation acceleration energy in order to prevent impurities from penetration through the gate insulating film. Ion implantation into the gate electrode is the same as that into the source/drain regions, so that the junction depth of the source/drain regions 109 becomes shallow. Since the threshold voltage adjusting region 104 is formed in the surface layer of the silicon substrate, the impurity concentration is increased.
A pn junction between the source/drain regions 109 and the threshold volatge adjusting region 104 has a large junction capacitance. Since the source/drain region junction is shallow, a distance between the silicide region 110 and the pn junction becomes short and leak current is likely to flow, assuming a constant depth of the silicide region 110. As described above, the shallow source/drain regions result in an increase in capacitance and leak current and a serious obstacle against a circuit operation.
If the silicide region 110 protrudes downward by the influence of the concave portion on the STI region surface and the conductive plug 114 extends lower than the active region surface, the distance between these conductive regions and the pn junction becomes short. This is the main cause of leak current, among others.
A phenomenon called channeling in silicon crystal is known. As Ion implantation is performed into silicon crystal along a particular direction, atoms are implanted deeper than other methods. This phenomenon is due to the structure established in crystal, called "channel", through which atoms are easy to move.
If silicon crystal is made amorphous, a channel specific to the crystal disappears and the channeling is hindered. There are various proposals for limiting an arrival depth of implanted ionic atoms by making silicon crystal amorphous before ion implantation is performed. For example, it is known that silicon crystal can be made amorphous by implanting ionic Ge which is the same group element as Si. Since Ge is the same group element as that of Si, the electric characteristics are not influenced fundamentally.
Japanese Patent Laid-open Publication No. HEI-9-23003 discloses the following method. After ion implantation for extension regions, side wall spacers are formed. For an n-channel transistor, phosphorus ions are implanted at an acceleration energy of 20 keV to 60 keV and a dose of about 1×1013 cm−3 to 3×1014 cm−3, and for a p-channel transistor, silicon ions are implanted to make silicon preliminarily amorphous for channeling prevention, and thereafter boron ions are implanted at an acceleration energy of 10 keV to 30 keV and a dose of about 1×1013 cm−3 to 3×1014 cm−3, to thus form deep source/drain regions.
After the deep source/drain regions are formed, silicidation is performed. Thereafter, ion implantation is further executed to increase the impurity concentration of a region under the silicide layer and lower parasitic resistance.
Japanese Patent Laid-open Publication No. HEI-10-22503 proposes a suppression of an arrival depth of phosphorus (P) ions. In forming source/drain regions of an n-channel transistor, first As ions are implanted to make silicon crystal preliminarily amorphous and the P ions are implanted to prevent the channeling in the amorphous layer.

Semiconductor device manufacture method capable of supressing gate impurity penetration into channel


A hoist swivel shackle assembly used with others to hoist heavy objects such as dies and molds. The shackle includes a "U" shaped shackle member pivotal on a swivel body which is rotatable about an orthogonal axis on a base. Long term distortion of the shackle member is minimized by flanges on the ends of the legs of the shackle that slidably engage side bosses on the swivel body to absorb outward loading on the shackle. The shackle is pivoted to the swivel body member by a pair of pins with annular recesses, fixed in a pair diametrally opposite pin receiving bores in the swivel body member. These pins are held in the swivel body member by pressing a softened material into threaded bosses in the swivel body forcing it around the pins and into their recesses. Overloading the swivel shackle assemblies is minimized by an indicator that tells the operator when he has exceeded the safety angle of the shackle member.

Swivel shackle assemblies have been used for many years in conjunction with cables and a hoist to lift and move heavy objects about the workplace, such as dies, molds, heavy castings, etc. These swivel shackle assemblies typically include a "U" shaped shackle member that is pivotal on a swivel body that in turn is rotatable about an axis on a base that is perpendicular to the swivel axis of the shackle on the base. This enables the shackle to accommodate two axes pivotal movement which is necessary for the geometry of the hoist arrangement.
In a typical hoist arrangement, an overhead crane has a depending single cable that is tied to four(more or less) outwardly extending cables connected to the shackle assemblies. Each shackle assembly typically has a threaded fastener extending centrally there-through that bolts the shackle directly to the top surface of the die or mold.
There have been found to be several problems associated with these prior shackle assemblies that we have observed over many years of manufacturing and testing these shackles. The first is that the "U" shaped shackle member that includes generally spaced parallel legs that are pinned at their ends to the swivel body, tend to spread apart after either extensive use, or sometimes upon overloading. To our knowledge no solution has, prior to the present invention, been devised for either ameliorating or eliminating this very fundamental problem.
A second problem results in the improper design of the hoisting arrangement by the hoist operator or his assistants. As noted above, each of the shackles is tied to a single hoist cable by an angularly related branch cable, and it can be simply shown that the load on each of the shackles is proportional to the angle of the shackle branch cables to a vertical axis. That is, as the angle of the shackle branch cable increases with respect to the vertical axis, the load on the shackle increases for a pre-determined load mass, which of course is a vertical load. To our knowledge, none of the shackle assemblies previously devised has provided the operator with any warning or indication as to an unsafe angle on the shackle member, that may cause failure of the shackle assembly.
The following patents are representative of the prior art relating to dual axis hoist shackle assemblies.
The Andrewe, et al., U.S. Pat. No. 3,297,293, issued Jan. 10, 1967; the Tsui, et al., U.S. Pat. No. 4,705,422, issued Nov. 10, 1987; and the Chandler, U.S. Pat. No. 5,352,056, issued Oct. 4, 1994, all show swivel shackle assemblies having a "U" shaped member or shackle that is pinned to a rotary swivel member by transverse pins that are separate from the "U" member itself. In this design, it is necessary to fix these shackle pins in the swivel body, and this design is particularly prone to "U" members spreading either as a result of long term fatigue or overloading.
A second group of patents represented by the Wong, et al., U.S. Pat. No. 4,570,987, issued Feb. 18, 1996; the Tsui, et al., U.S. Pat. No. 4,641,986, issued Feb. 10, 1987; and the Tsui, U.S. Pat. No. 5,405,210, issued Apr. 11, 1995, show hoist swivel shackle assemblies in which the ends of the "U" shaped shackle extend radially inwardly and form the pivotal bosses for the shackle on the swivel body member. This design somewhat reduces the long term loading problem on the shackle discussed above, but it does not significantly minimize that problem.
Furthermore, in none of the prior swivel shackle assemblies discussed above is there any provision for a device that indicates to the operator when an excessive shackle angle is placed on the shackle causing a potentially hazardous condition.
It is a primary object of the present invention to ameliorate the problems noted above in hoist swivel shackle assemblies.


Generally described, the present application corresponds to the management of journaling messages in a messaging environment. A set of electronic messaging clients can be associated with a designated journaling destination that may be different from a default journaling destination associated with each individual messaging client. Additionally, the messaging environment can alternate between multiple designated journaling destinations to increase the mail load that a single journal destination can manage. The messaging environment can evaluate journaling criteria to select alternate designated journaling destinations from a set of available alternate journaling destinations.

Generally described, electronic messaging platforms, such as Microsoft Corporation's Exchange messaging platform, can provide a mechanism to capture copies of electronic messages, such as electronic mail or email, generated or delivered to the electronic mail messaging platform. Typically, a server or servers in the messaging platform that maintains the rules governing the creation and delivery of the captured copies, which may be referred to as journal receipts or journaling messages. Journal rules contain a few properties, such as the delivery address and the scope of messages to determine which journal receipts should be generated.
Journal receipts are delivered to dedicated journaling destination, such as one or more mailboxes in the messaging platform, for storage and review. Organizations will architect the journaling infrastructure to accommodate the volume of email traffic that will be generated; higher volumes of email traffic will require more mailboxes and servers to process the journal stream. Many organizations will have multiple journal mailboxes. However, multi journal mailbox architectures introduce complexity and data duplication, leading to increased IT expenditures to manage and control electronic mail. For example, if end users that send email to each other are subject to journal rules, but journal to different journal mailboxes, then a separate journal receipt will be delivered to each journal mailbox, duplicating the journal receipt unnecessarily. This duplication manifests as increased message volume and storage consumption in the email system.


A method of fabricating a pixel structure is disclosed. A substrate having a color filter layer thereon and a leveling layer further covers the color filter layer is provided. A first metal layer is formed over the leveling layer. The first metal layer is patterned to define a source/drain. A channel material layer, a gate insulating layer and a second metal layer are formed over the substrate to cover the source/drain. The second metal layer, the gate insulating layer and the channel material layer are patterned to define a gate and a channel layer. A passivation layer is formed over the substrate to cover the gate. The passivation layer is patterned to expose a portion of the drain. A transparent conductive layer is formed over the substrate, and is electrically connected to the exposed drain. Thereafter, the transparent conductive layer is patterned to form a pixel electrode.

1. Field of the Invention
The present invention relates to a method of fabricating a pixel structure, and more particularly, to a method of fabricating a pixel structure using the array on color filter (AOC) technique.
2. Description of the Related Art
A Thin Film Transistor Liquid Crystal Display (TFT LCD) is generally composed of a TFT array substrate, a color filter array substrate, and a liquid crystal layer between two substrates. In addition, in an alternative method of fabricating LCDs, the TFT array is fabricated on the color filter array, called an array on color filter (AOC) technique. In other words, in such method, a color filter array is formed over the substrate, and the TFT array is formed over the color filter array later.
In general, the TFT array substrate comprises a plurality of pixel structures, wherein each pixel comprises a TFT and a pixel electrode that is typically formed by a five-photomask process. Wherein, in the first photomask process, a first metal layer is defined for forming components such as a scanning line and a gate of the TFT. In the second photomask process, a channel layer of the TFT and an ohmic contact layer are defined. In the third photomask process, a second metal layer is defined for forming components such as a data line and a source/drain of the TFT. In the fourth photomask process, a passivation layer is patterned. In the fifth photomask process, a transparent conductive layer is patterned for forming a pixel electrode.
However, following the trend of larger-sized TFT LCDs, different kinds of problems and challenges, such as lowering yield rate and decreasing production capacity, are inevitable. Therefore, if the number of photomasks during the TFT fabricating process can be reduced, or the steps of exposure process in fabricating the TFT components can be reduced, the fabricating time can be reduced, the production capacity can be improved, and the manufacturing cost can be lowered.
A four-photomask process had been introduced and commonly used in manufacturing pixel structures, wherein one of the photomasks having halftone patterns is used, to reduce one photomask. However, for the photomask with halftone patterns, the photomask layout is harder to design and the choice of photoresist may be insufficient. In addition, in photomasks with halftone pattern, the photoresist patterns after exposure are usually not ideally uniform.


An antenna selection method and a terminal, where the terminal includes m primary antennas configured for a first application program and n secondary antennas, where m≥1, and n≥1. The method includes, when the terminal is in a WI-FI connected state and a landscape state, obtaining a key factor and a radio frequency indicator that are of each of m+n antenna combinations, determining a first antenna combination based on the key factor and the radio frequency indicator, where the first antenna combination is a first-priority antenna combination of the m+n antenna combinations, and the first antenna combination includes at least one of the secondary antennas, and using the first antenna combination to perform communication for a second application program.

With development of mobile devices, more APP applications (for example, game applications and video applications) require a user to hold and operate the terminals in a landscape mode. An antenna for receiving a Wi-Fi signal is usually designed to be in a corner or bezel of the terminal. As shown in FIG. 1, two antennas of a terminal are disposed in positions of an antenna 0 and an antenna 1. Therefore, when the mobile phone is in the landscape state, hands of a user hold the antennas, consequently affecting signal reception of the antennas and causing "death grip" when the mobile phone is in a Wi-Fi connected state. This deteriorates Wi-Fi performance and severely reduces user experience.
Currently, to resolve a problem that Wi-Fi performance deteriorates when the mobile phone is in the landscape state, an antenna switching method is disclosed in some technologies. According to the method, signal quality of a Wi-Fi signal received by a Wi-Fi antenna is first detected, for example, a signal strength, a transmission speed, or a packet loss rate; and when the signal quality is less than a threshold, another antenna with better signal quality is switched to, to resolve a problem that an original antenna is blocked.
According to the existing antenna switching method, only the secondary diversity antenna is used to replace the original blocked primary antenna, and impact on an original antenna system resulting from the switching is not considered. Therefore, communication effect of an antenna system may be still poor after the switching is performed. For example, in a multiple-input multiple-output (multiple-input multiple-output, MIMO) technical scenario, for example, for a 4-transmitter 4-receiver (4T4R for short) terminal device, because one antenna is blocked, it is necessary to switch to a new antenna combination and use the new antenna combination for communication. However, this is not an optimal solution to achieving a MIMO effect, further may affect Wi-Fi performance, and make it difficult to improve user experience.


Provided is an apparatus and method for detecting a packet of a zero-padded OFDM signal, which are capable of determining if a packet exists in a reception (RX) signal by comparing a cross-correlation value of an OFDM signal delayed by a predetermined sample time, e.g., a zero-padded sample time, with a power value of the RX signal, thereby increasing a packet detection probability and preventing a false alarm. The packet detecting apparatus includes: a cross-correlation calculator for calculating a cross-correlation value of a reception signal received from the outside and delaying the calculated cross-correlation value by a predetermined sample time; a power calculator for calculating a power value of the reception signal; and a packet detector for determining if a packet exists in the reception signal by comparing the delayed cross-correlation value with the calculated power value, and detecting the corresponding packet.

1. Field of the Invention
The present invention relates to an apparatus and method for detecting a packet of an Orthogonal Frequency Division Multiplexing (OFDM) signal; and, more particularly, to an apparatus and method for detecting a packet of a zero-padded OFDM signal, which are capable of determining if a packet exists in a reception (RX) signal by comparing a cross-correlation value of an OFDM signal delayed by a predetermined sample time, e.g., a zero-padded sample time, with a power value of the RX signal, thereby increasing a packet detection probability and preventing a false alarm.
This work was supported by the IT R&D program of MIC/IITA [2006-S-071-02, "Development of UWB Solution for High Speed Multimedia Transmission"].
2. Description of Related Art
A conventional packet detector for an OFDM system separately calculates a cross-correlation value and a power value of an RX signal. The conventional packet detector determines whether a packet of the RX signal is detected or not by comparing a cross-correlation value of a preamble sample with a value obtained by multiplying the power value of the RX signal by a preset threshold value.
An operation of the conventional packet detector will be described below in detail.
The conventional packet detector for the OFDM system calculates cross-correlation values of N preamble samples by using a cross-correlation function, which is expressed as the following Equation 1.
                              Cor                                (            n            )                          =                                                                        ∑                                  i                  =                  0                                                  N                  -                  1                                                                                r                                                        (                                          n                      -                      i                                        )                                                                                p                    *                                                                          (                                          N                      -                      1                      -                      i                                        )                                                                                            2                                    Eq        .                                          1
where Cor(n) is a cross-correlation value at an n-th sample time, r(n) is the RX signal received at the n-th sample time, and p*(j)(j=0, . . . , N−1) is a conjugate complex number of a j-th preamble sample previously stored in a packet detector of a receiver.
In Equation 1, |a|2=Re(a)2+Im(a)2 , where |a|2 is a value obtained by summing a square of a real part of the complex number "a" and a square of an imaginary part of the complex number "a".
The conventional packet detector for the OFDM system calculates the power values of the RX signal, based on the following Equation 2. That is, the conventional packet detector sums the square of the real part and the square of the imaginary part of the RX signal received at each sample time and stores the resulting values in N buffers. Then, the conventional packet detector calculates the power values of the RX signal by summing the squares of the RX signal stored in the N buffers.
                              Pow                                (            n            )                          =                              ∑                          i              =              0                                      N              -              1                                                                                                  r                                                  (                                      n                    -                    i                                    )                                                                    2                                              Eq        .                                          2
where Pow(n) is the power value at an n-th sample time, and r(n) is the RX signal received at the n-th sample time.
Then, the conventional packet detector multiplies the power value of the RX signal, which is calculated using Equation 2, by a preset threshold value (Threshold_value), as expressed in the following Equation 3.
The conventional packet detector determines if the cross-correlation value Cor(n) calculated using Equation 1 is greater than the value obtained by multiplying the power value Pow(n) calculated using Equation 2 by the threshold value Threshold_value, as expressed in the following Equation 3. The power related threshold value is applied to a packet detection process of the packet detector after an optimal value is selected through a simulation and test under a variety of channel environments.Cor(n)>Pow(n)×Threshold_value   Eq. 3
where Cor(n) is the cross-correlation value at the n-th sample time, Pow(n) is the power value of the RX signal received at the n-th sample time, and Threshold_value is the preset power related threshold value.
If the cross-correlation value Cor(n) is greater than the value obtained by multiplying the power value Pow(n) by the threshold value Threshold_value, the conventional packet detector determines the packet as being detected from the RX signal.
If the cross-correlation value Cor(n) is greater than the value obtained by multiplying the power value Pow(n) by the threshold value Threshold_value, the conventional packet detector determines the packet as being detected from the RX signal, transmits the determination value to a controller of a receiver, and terminates the packet detection process.
The conventional packet detector for the OFDM system has a problem in that a packet detection probability is reduced in a channel environment where multi-path is serious. This is because the cross-correlation value in the channel environment where the multi-path is serious becomes relatively smaller than the cross-correlation value in a channel environment where no multi-path exists. The packet detection process is performed by comparing the cross-correlation value with the value obtained by multiplying the power value Pow(n) by the power related threshold value Threshold_value. Thus, if the cross-correlation value becomes small, the packet detection probability will be reduced.
In addition, the conventional packet detector for the OFDM system has a problem in that a false alarm increases in a channel to which additive white Guassian Noise (AWGN) is applied. For example, when a signal-to-noise ratio (SNR) of an RX signal is 0 dB in an ultra wide-band (UWB) channel environment, a false alarm may occur at more than 10% of transmission frames and a packet detection may frequently fail.
Furthermore, in the case of the OFDM system that transmits the preamble pattern generated by repeating a code set with a predetermined length, if a cross-correlation value is calculated through the conventional packet detector, a peak value is obtained at a reference position, but a cross-correlation value with a predetermined magnitude is periodically obtained at positions other than the reference position. If the conventional packet detection method is applied with the power related threshold value set to a small value, the packet may be frequently detected at undesired positions other than the reference position.

Apparatus and method for detecting packet of zero-padded OFDM signal

Electronics and Telecommunications Research Institute


A thermoplastic compound is formed using a blend that includes one of processed fly ash, cinders and processed fly ash and cinders with a fractional melt having a melt flow index of less than 1 or a low melt resin with a melt flow index between 1 and about 3 or both, and a resin compatible with the fractional melt or low melt resin and having a melt flow index that is different from the melt flow index of the fractional melt or the low melt resin. Presence of the processed fly ash and cinders is believed to reduce cycle time for forming the thermoplastic compound into a plastic product from about 5 percent to about 30 percent merely because of the presence of the processed fly ash and cinders. Presence of the processed fly ash and/or cinders also permits the increased use of more fractional melt than conventionally attempted and also allows for use of thermoplastic regrind from recycling sources.

The use of fillers with resins is well known to reduce the use of the amount of resin, particularly thermoplastic resin, and to control mechanical properties of the resulting composition. Many resins are processed through injection molding machines, vacuum molding machines, roto molding machines, extrusion machines and the other similar machines. Typically the resin material is heated and mechanically processed in some way to form a desired structure that must be cooled or cool in some way to attain the desired mechanical characteristics for the desired product. Throughput or speed of production is an important issue that is addressed in selecting materials and machines for manufacturing a wide variety of thermoplastic materials.
Fly ash and cinders are by-products of the oxidation (e.g., combustion) of hydrocarbon fuels like coal. For example, power plants for generating electricity are known to generate substantial quantities of fly ash and cinders every day as they burn fossil fuels like coal and natural gas. Fly ash typically is composed of or includes some residual hydrocarbon that has not combusted along with unburned residue of materials that had been part of the fuel before it was burned. That is, the fly ash and cinders are the by-product, residue or result of a previous industrial process and thus can be referred to as a "post industrial" material which in this case is inorganic and, as discussed hereinafter, is useful as a filler. Processes and products that use a post industrial material are desired as one is, in effect, recycling.
The fly ash is so light or buoyant that it becomes entrained with the exhaust gases and moves up or "flies" up or out of the exhaust structure (e.g., a chimney). Typically, the fly ash is collected from the exhaust structure and stored, stockpiled and/or taken to suitable disposal sites. Some cinders are similarly quite light and small so they can be entrained with the fly ash. Some cinders can be of a larger size which typically fall to the bottom of a combustion structure and/or an exhaust structure. The fly ash and the cinders each can be separated into specific particle sizes.
U.S. Pat. No. 7,879,939 (Prince, et al.) (hereinafter the "'939 Patent"), which is incorporated by reference as if fully rewritten herein, discloses use of fly ash and cinders as a filler in the manufacture of plastics. To create suitable fly ash and cinder material from different sources, they can be processed to attain a desired particle size distribution (PSD) as suggested in U.S. Patent Publication US 2011/0071252 published on Mar. 24, 2011, (herein the '252 Application) the disclosure of which is incorporated by this reference. The PSD and cinder content can be controlled to vary processing parameters and the physical properties of a physical product made from selected resins which include thermoplastics. Inorganic fillers can also be processed as set forth in United States Patent Application for a METHOD TO HEURISTICALLY CONTROL FORMATION AND PROPERTIES OF A COMPOSITION, Ser. No. 61/491,091 filed May 27, 2011 (the "'091 Application").
The term "fractional melt" applies to one or more resins and other chemicals that have a melt flow index than is a fraction or less than 1.0. The melt flow index ("MFI") is a measure of the flow of a melt of a thermoplastic. Specifically it is the mass of the polymer flowing in ten minutes through a capillary of a specific diameter and length as outlined in standard ASTM D 1238 promulgated by the American Society for Testing and Materials.
A fractional melt having a weight percent from about 5% to 10% of a thermoplastic is not usually suitable for injection molding or processes that involve the flowability comparable to injection molding. Loading percentages higher than 5% to 10% weight percent can be achieved but only when processed at higher than normal processing temperatures of over 450° F. (232° C.) for polyolefins and at very high internal injection pressures as well. These higher than normal temperatures and pressures for fractional melt resins are known to cause degradation of the physical properties of the resulting products.
A "low melt" resin means a resin that has a melt flow index of about 3 or less and greater than 1 that functions comparably to a fractional melt resin.
For purposes of this invention, a "low index" resin may be "low melt" resin and/or a "fractional melt".
Products formed that include fractional melts and low melt resins with improved or acceptable physical properties and that require less energy to produce are not known.


A pressure support device includes a humidification system (10) to control the humidity of a pressurized flow of breathable gas generated by the pressure support device. The humidification system includes a liquid storage chamber (32) and a humidification chamber (34). When in an operational orientation, liquid travels from the liquid storage chamber to the humidification chamber through a serpentine feed path (38) due to gravity. The serpentine shape of feed path halts the flow of liquid responsive to the device being tilted out of an operational orientation.

1. Field of the Invention
The present disclosure pertains to a method and apparatus for preventing liquid ingress from a humidifier into in a pressure support device, and, in particular, for preventing liquid ingress resulting from a tilting of the humidifier pressure support device.
2. Description of the Related Art
Pressure support devices configured to provide a pressurized flow of breathable gas to the airway of a subject are known. Humidifiers are included in some conventional devices in order to control the humidity of the pressurized flow of breathable gas that is generated. These humidifiers generally require storage of a reservoir of liquid, such as water. When conventional devices are transported, jostled, or improperly used, they may be tilted with respect to their intended operational orientation. This tilting may cause a flow of liquid from the storage reservoir into other areas of the device which may reduce the efficiency and/or effectiveness of the device, cause the device to stop working, damage the device, and/or have other undesirable consequences.
Existing humidifiers also need to contain a sufficient quantity of water so as to deliver enough moist air to a patient during a typical 8 hour sleep period. This requires that the water chamber be large enough to deliver therapy at worst case ambient conditions. Also, to greatly reduce or eliminate the chance of water damage to the therapy device, the water chamber is typically sized to accommodate the defined water volume during drop and rotation of the therapy device. This requires the water chamber to be larger in volume than what is required for therapy. This increase in chamber volume is typically 1.5 to 2 times the defined water volume, i.e. if the tank need to hold 325 ml of water for therapy requirements, the tank may need to be designed to hold up to 650 ml of water to eliminate water ingress back into the therapy device during misuse conditions. This large water volume requires a bigger footprint for the overall therapy system, adds weight and is harder to transport.
Furthermore, conventional humidification systems typically utilize a resistive heater to heat a large mass of water all at once. This bulk heating approach takes longer for the humidifier to heat up and uses more energy.

Humidifier with liquid ingress protection


The present invention relates to peptides of CaV2.2 and their use in the treatment of pain. The sequence of the peptides is derived from the C-terminus of CaV2.2. and is believed to inhibit the interaction of CaV2.2 with Mint1-PDZ1. The invention is related to use of this peptide to treat pain and to use of this peptide in binding reaction with int-PDZ to screen for small molecules that can inhibit pain.

1. Field of the Invention
The present invention relates to fields of molecular biology and pathology. More particularly, the present invention relates to peptides of CaV2.2 and methods for their use in the treatment of pain.
2. Description of Related Art
There are six distinguishable types of voltage-dependent calcium channels (VDCC) presently described, designated L-type, N-type, P/Q-type, L-type, R-type, and T-type, which are expressed throughout the nervous system (Tsien et al., 1991). Presynaptic voltage-gated Ca2+ channels mediate rapid Ca2+ influx into the synaptic terminal that triggers synaptic vesicle exocytosis and neurotransmitter release (Llinas et al., 1981). N-type Ca2+ channels, encoded by CaV2.2 pore-forming subunit (Williams et al., 1992; Ertel et al., 2000) and P/Q-type Ca2+ channels, encoded by the CaV2.1 pore-forming subunit (Mori et al., 1991; Ertel et al., 2000), play a predominant role in supporting chemical neurotransmission in central synapses (Takahashi and Momiyama, 1993; Wheeler et al., 1994; Dunlap et al., 1995; Reuter, 1995). Sensation of pain is mediated by nociceptive neurons in the dorsal root ganglia (DRG) (McCleskey and Gold, 1999; Yaksh, 1999). N-type voltage-gated Ca2+ channels (Cav2.2) are abundantly expressed in DRG neurons (Kerr et al., 1988; Gohil et al., 1994; Westenbroek et al., 1998) and play a predominant role in control of glutamate release from DRG neurons in the spinal cord. Thus, inhibition of N-type Ca2+ channels is expected to have anti-nociceptive effect. Indeed, studies have suggested that N-type calcium channel antagonists are mainly effective in reducing pain associated with inflammation and tissue/nerve injury, although some effect has been shown in acute models of pain. Anti-nociceptive effects of L- and P/Q-type VDCC antagonists have also been reported; however, these effects appear to be moderate at best.
Pain can be essentially divided into 2 broad categories: physiological pain and pathological pain. Physiological pain is good for the organism in that it is protective. To prevent damage to tissue, physiological pain pathways are activated by noxious stimulation. Physiological pain must only be controlled under specific clinical situations, such as during surgery, medical procedures, or following trauma. Drugs that chronically disable pathways that transmit physiological pain are undesirable as they cause the organism to lose the protective function of pain. Pathological pain, on the other hand, is not the result of a noxious stimulation or healing tissue. Pathological pain originates from abnormal function of the nervous system due to nerve lesion or compression, neuropathy, tumor growth, or tissue inflammation. Current therapeutics that are used for the treatment of pathological pain are typically limited by serious side effects and the development of tolerance.
Pain researchers developed three classes of pain animal models: acute (physiological) pain model (hot plate, tail flick, paw pressure), inflammatory models (carrageenan and formalin), and nerve injury (sciatic nerve ligation, focal spinal injury) (Yaksh, 1999). A biphasic behavioural response is observed in the formalin model. The phase I of the response (1-10 min after injection) corresponds to acute afferent input resulting from the activation of primary afferent neurons. The phase II of the response (10-60 min) results from sensitization of spinal responses and considered to be an appropriate model for persistent pain (Yaksh, 1999).
Consistent with the role of N-type Ca2+ channels in pain pathway, pharmacological block of N-type Ca2+ channels by single injection or continuos infusion of synthetic ω-conopetide SNX-111 inhibited phase II formalin response in rat animal model (Malmberg and Yaksh, 1994, 1995). The role of N-type Ca2+ channels in pain pathway was further supported by analysis of Cav2.2 knockout mice (Hatakeyama et al., 2001; Kim et al., 2001; Saegusa et al., 2001). All 3 groups observed supression of phase II formalin response in Cav2.2 −/− mice when compared to wild type mice.
These results pointed to N-type Ca2+ channels as potential drug target for a treatment of persistent pain. Based on this idea, Elan Pharmaceuticals (initially Neurex) developed a drug Ziconotide (SNX-111, a synthetic version of ω-conotoxin MVIIA). Very promising results were obtained with Ziconitide in clinical trails and currently FDA is considering Ziconotide for approval. However, although Ziconotide is highly effective for treatment of chronic pain, thare is also a number of problems associated with its use. Ziconitide (SNX-111) is a polypetide with a complex chemical structure and very difficult to synthesize. Ziconitide does not pass blood-brain-barrier and has to be delivered by pump infusion directly into a spinal cord, greatly limiting score of its applications. In addition, a number of severe side-effects were reported in some patients in response to Ziconitide (Penn and Paice, 2000).
It has been demonstrated that neuron-to-neuron contact is required for N-type Ca2+ channel clustering during synapse formation in rat hippocampal neuronal culture (Bahls et al., 1998). More recently, synaptic targeting of an auxiliary P/Q-type Ca2+ channel subunitβ4 was investigated (Wittemann et al., 2000). The present inventors have previously investigated targeting of recombinant N-type Ca2+ channels to synaptic locations in rat hippocampal neuronal cultures. It was found that in immature and in mature low-density hippocampal cultures, recombinant N-type Ca2+ channels are uniformly distributed in both axonal and somatodendritic compartments. In contrast, in mature high-density cultures, the recombinant N-type Ca2+ channels are clustered in presynaptic sites and primarily excluded from the somatodendritic domain. Synaptic clustering of recombinant N-type channels depended critically on the most C-terminal region of the "long" splice variant of the N-type Ca2+ channel pore-forming subunit CaV2.2a (Williams et al., 1992; Ertel et al., 2000).
In another earlier study, the inventors identified postsynaptic density-95 (PSD-95)/discs large/zona occludens-1 (PDZ) and Src homology 3 (SH3) domainbinding motifs in the same region of the CaV2.2 subunit (Maximov et al., 1999). The association of CaV2.2-NC1 C termini with the Mint1/CASK/veli-neurexin/neuroligin complex (Maximov et al., 1999) provides a possible molecular mechanism for N-type Ca2+ channel synaptic targeting during synaptogenesis, and the association of CaV2.2a-NC1 C terminal with Mint1-PDZ1 and CASK-SH3 domains (Maximov et al., 1999) links synaptic N-type channels to neurexin-neuroligin neuronal adhesion complex (Irie et al., 1997; Nguyen and Sudhof, 1997; Butz et al., 1998; Song et al., 1999) and synaptic clustering of the channels and synaptic organization (Fanning and Anderson, 1996; Komau et al., 1997; Craven and Bredt, 1998). The importance of N-type channel association with Mint1 and neurexins is consistent with impaired presynaptic function in neurons from Mint1 kockout (Ho et al., 2003) and α-neurexins (Missler et al., 2003) knockout mice.
More recently, the inventors have shown that CaV2.2 C termini also bind to INADL-5, PAR6, and MUPP1-9 PDZ domains (Bezprozvanny and Maximov, 2001) and that the proline-rich region of the CaV2.2 C-terminus has been implicated recently in interactions with the SH3 domain of RBP (Hibino et al., 2002). Subsequently, the inventors also demonstrated that these motifs act as synergistic synaptic targeting signals for N-type channels in rat hippocampal neurons (Maximov and Bexprozvanny, 2002). The inventors also demonstrated that introduction of CaV2.2 carboxy-terminal sequence into hippocampal neurons by transfection impairs their presynaptic function (Maximov & Bezprozvanny, 2002). However, there have yet to be reported attempts to specifically block these interactions and determine the ensuing biological consequences, particular with regard to pain.

Board of Regents, The University of Texas System


A system for completing a series of calls from a calling party to a plurality of called parties served by a common terminating switch and located in the same general geographic area, is implemented by a) establishing a first communication path from the calling party to the terminating switch b) establishing a second communication path from the terminating switch to the the called party using routing information received from the calling party regarding the called party c) bridging those two communication paths to form a complete connection from the calling party to the called party d) preserving the first communication path and reusing it to complete all the calls in the series.

As is well known, telecommunication systems route and complete telephone calls by a) receiving called party information-typically a seven-digit or ten-digit telephone number provided by a calling party b) using that information to establish a telecommunications connection, and c) at the termination of the call, "tearing down" the connection, thereby releasing the telecommunications resources that were used in the connection to allow appropriation of these resources to establish connections for subsequent calls between other calling and called parties.


A memory cell array includes a plurality of floating body memory cells, which are arranged in cell rows, and world lines, wherein each word line is configured to control memory cells associated with a pair of cell rows. The memory cell array also includes bitlines, wherein each bitline is electrically connected to an individual memory cell of each pair of the cell rows.

Single-transistor floating body memory cells base upon charge storage effects in an insulated floating semiconductor body. The floating body is sandwiched between two source/drain regions, wherein the first source/drain region may be connected to a source line or a common source plate and a second source/drain region may be connected to a bit line. A gate electrode is configured to switch a current between the two source/drain regions by a select voltage applied to the gate electrode. By applying a suitable write signal to the gate electrode or to the gate electrode and the source line/common source plate, charge may be injected in or removed from the floating body in accordance to a voltage supplied to the bit line. By applying a suitable read signal to the gate electrode or to the gate electrode and the source line/common source plate, an output signal may be caused in the bit line, wherein the output signal depends on the amount and/or type of charge stored in the floating body region. Typically, the read signal differs from the write signal, for example with regard to the voltage amplitude.
A need exists for integrated circuits comprising a high density floating body memory cell array and simple peripheral circuitry for addressing the memory cells of a floating body memory cell array.

Memory cell array comprising floating body memory cells


An adjustable spanner wrench for various spanner head work piece having different size holes where various spanner driver element are able to be stored on the arms of the wrench itself, instead of being stored somewhere else in a separate container where they can be easily lost or misplaced.

1. Field of the Invention
The present invention relates to spanner wrenches and more particularly to adjustable spanner wrenches with multiple, self-carried, differently sized spanner driver elements.
2. Description of the Prior Art
Numerous innovations for adjustable spanner wrench for spanner head work pieces having different size holes have been provided in the prior art that will be described. Even though these innovations may be suitable for the specific individual purposes to which they address, accordingly they differ from the present invention.
A FIRST EXAMPLE, U.S. Pat. No. 4,676,126 to Polastri teaches an adjustable wrench head is disclosed for use in conjunction with spanner nuts of various sizes, each spanner nut having a plurality of locking recesses therein. More particularly, a wrench head is provided which includes a central elongated driving spindle having a plurality of opposed pairs of planar guide rails projecting radially outwardly therefrom. Each pair of guide rails defines a channel, which is adapted to receive a generally rectangular insert, with the insert being radially movable therein, relative to the central spindle. Each insert is provided with a tang which projects axially beyond the front end of the spindle for engagement with a locking recess of the spanner nut. The radial position of the inserts are adjusted and secured such that the tangs thereof are spaced from the center of the spindle a distance corresponding to the radius of the spanner nut. Preferably, a plurality of planar webs are provided which extend between one guide rail of one pair and the adjacent guide rail of another pair. The planar webs function to add structural rigidity to the wrench head and prevent deflection of the guide rails.
A SECOND EXAMPLE, U.S. Pat. No. D337,492 to Ryan, et al. shows the ornamental design for a folding spanner wrench.
A THIRD EXAMPLE, U.S. Pat. No. 5,347,891 Kamp, et al. teaches an adjustable wrench assembly for installing and removing a threaded cap member of an hydraulic cylinder assembly includes a head member adapted to partially surround the piston rod of the cylinder assembly. A cover plate attaches to the head member to completely surround the piston rod. A plurality of adjustable contact pins accommodate various sizes of piston rods and are engagable with the piston rod to keep the wrench square and prevent it from twisting. Various sizes of adapter plates are connectable to the head member and include a plurality of engagable pins to engage mating slots or holes in the cap member. The adjustable contact pins include non-metallic plastic contact portions to prevent marring of the piston rod.
A FOURTH EXAMPLE, U.S. Pat. No. 5,469,766 to Hodges teaches an adjustable spanner wrench comprising of a pair of handle halves, the handle halves including a first handle half and a second handle half, the first handle half being provided with an interior channel along its length. Jaws in the form of two C-shaped arms, the C-shaped arms each having an outboard extent with an aperture therethrough, each C-shaped arm having an inboard extent with an aperture and an associated rivet coupling the outboard ends of the handle halves to the inboard extents of the arms. A pivotable clip having a free end and a pivot end pivotally secured to each outboard end of each C-shaped arm and a semicircular recess at its free end, the semicircular recess adapted to be moved in position concentric with its associated aperture for contacting the groove of the pin received in an aperture.
A FIFTH EXAMPLE, U.S. Pat. No. 6,305,254 to Hsieh teaches a combination tool kit includes an elongated casing, a hexagon head socket holder mounted in the casing between front and rear ends of the casing and holding a set of hexagon head sockets adapted for turning bolts and nuts, a combination wrench pivoted to the front end of casing, the combination wrench having an open end and a box end at two distal ends thereof adapted for grasping and turning bolts and nuts, and a hexagonal spanner block pivoted to the rear end of casing, the hexagonal spanner block having a hexagonal box adapted to work with one of the hexagon head sockets stored in the hexagon head socket holder for turning bolts and nuts. The storage bin for the spare sockets is located at the back of the wrench, thus ruining proper weight distribution for a user.
A SIXTH EXAMPLE, McMaster Carr catalog shows three double armed spanner driver element spanner wrenches. None has provisions for spanner driver element storage thereupon.
Contrarily, the instant spanner wrench stores alternative sized spanner driver elements upon the length of its own arms. Thus, it maintains and contributes to proper weight distribution for a user for most efficient use and the ease of finding an locating a required sized set of spanner driver elements.

Adjustable spanner wrench for spanner heads having different size holes


A bead inductor with reliable electrical characteristics and which is constructed so as to be easily mass produced includes a substantially rectangular-parallelepiped core. The core includes an axial portion and an outer peripheral portion, and a coil is formed by winding a metal wire around the axial portion. The axial portion includes a central portion and a peripheral portion. A high strength material is used for the central portion. Metal caps are disposed on both ends of the core. The caps and the coil are connected electrically. In addition, the central portion of the axial portion may be a cavity.

1. Field of the invention
The present invention relates to a bead inductor, particularly a bead inductor having a coil disposed in a bead-like core.
2. Description of Related Art
FIG. 10 is an illustration showing an example of a conventional bead inductor. A bead inductor 1 includes a rectangular-parallelepiped core 2, for example. A coil 3 comprising a wound metal wire is disposed in the core 2. Ends of the coil 3 extend out to the opposite ends of the core 2. In other words, as shown in FIG. 11, the core 2 is formed by an axial portion 4 in the central portion thereof and a peripheral portion 5. The coil 3 is disposed on the periphery of the axial portion 4.
The peripheral portion 5 is disposed on the periphery of the coil 3. Furthermore, a metal cap 6 is disposed on the opposite ends of the core 2. The coil 3 is electrically connected to the metal cap 6. The metal cap 6 functions as a terminal for connecting with an external circuit.
In order to produce such a bead inductor 1, magnetic powder, such as a ferrite, is kneaded into resin, and a mixed material is produced. The axial portion 4 is formed by extrusion molding using the mixed material. The coil 3 is formed by winding a metal wire around the axial portion 4. Furthermore, the peripheral portion 5 is formed by extrusion molding using the mixed material and is formed on the periphery of the axial portion 4 after the coil 3 is formed. The bead inductor 1 is completed by fixing the metal cap 6 on the opposite ends of the core 2.
In the bead inductor 1, when a signal transmits through the coil 3, a flux is generated at the periphery of the coil 3, in other words, at the axial portion 4 and the peripheral portion 5. At this time, as shown in FIG. 12, a large inductance is produced at the inside and outside of the coil 3 by the axial portion 4 and the peripheral portion 5 having high permeability xcexc. Therefore, high frequency noise can be eliminated by transmitting a signal to the bead inductor 1. In addition, the cylinder in FIG. 12 shows the coil 3.
However, if the content of the magnetic powder kneaded into the resin increases, the molded structure using mixed material becomes brittle. Even if the axial portion is formed by extrusion molding, it becomes difficult to wind the coil and to store the axial portion as a half-finished product. Furthermore, when the peripheral portion is formed by extrusion molding on the periphery of the axial portion after the coil is formed, breaks and cracks occur in the axial portion. As a result, it becomes difficult to reliably produce a non-defective bead inductor using mass production processes. To avoid such an undesirable result, reducing the quantity of a magnetic powder in the core may be attempted. However, since the axial portion is the portion which the flux flows around, it is desirable that the permeability of the axial portion is high.
In order to overcome the problems described above, preferred embodiments of the present invention provide a bead inductor having reliable electrical characteristics and constructed so as to be capable of being manufactured easily using mass production processes.
According to one preferred embodiment of the present invention, a bead inductor includes a core made of a magnetic material and a coil made of a conductive material and disposed in the core, wherein a central portion inside of the coil is made of a material having high strength.
According to another preferred embodiment of the present invention, a bead inductor includes a core made of a magnetic material and a coil made of a conductive material disposed in the core, wherein a central portion inside of the coil is a cavity.
When a current flows in the coil, flux occurs in the core. At this time, not much of the flux is generated in the central portion of the coil and the flux concentrates in the vicinity of the coil. Thus, it is not necessary to construct the central portion of the coil where the flux is low with a high permeability material. Instead, the central portion can be formed with a high strength material. Moreover, if at the time of molding, a required strength of the axial portion can be secured, the bead inductor can be mass-produced reliably. Therefore, even if the central portion of the coil is removed after molding, the proper operation and function of the bead inductor can be secured.
The above-described elements, features, and advantages of the present invention will be further clarified by the detailed descriptions in the description of the preferred embodiments which will be described below by referring to the drawings.


A passive filter device for a capacitor in series with a substantially inductive transmission line of an electric transmission system is disclosed. The passive filter device comprises a double-loop RCL filter in parallel with the series capacitor. At power frequency, the filter device allows the power frequency current to pass through the series capacitor with minimum power losses. At sub-synchronous resonance frequencies, the passive filter device provides bypassing of the series capacitor with maximum selectivity of the RCL filter.

In electrical power systems, damaging oscillations known as sub-synchronous resonance (SSR) oscillations occur when energy is interchanged between a torsional system of a turbine generator and a series-compensated transmission network via a generator air gap, at one or more natural frequencies of the combined system. Since the electric utility turbine generators of these systems may be seriously damaged through SSR oscillations, several approaches have been taken to compensate for and/or filter out these damaging oscillations.
One such approach is discussed in U.S. Pat. No. 5,367,197 "Series Capacitor Equipment" by Klerfors, which is hereby incorporated by reference. Klerfors discloses an "active-type" filter wherein a controllable circuit comprising an inductor and controllable semiconductor connection is connected in parallel to the series capacitor of a series-compensated transmission network. The filter transforms the energy of the subharmonic oscillation into fundamental frequency power and returns it to the power network. Some disadvantages in using this and other active-type filters with controllable semiconductor connections are as follows: many components are usually involved; the control device that is utilized may require sophisticated detection and control means; the thyristor switching process may create undesired harmonics that lower the quality of the power supply; and finally, the cost is generally high.
Another approach of filtering out undesirable SSR oscillations in transmission lines with series capacitors is through passive filters. Two examples of passive filters are disclosed in the following U.S. Patents which are hereby incorporated by reference. U.S. Pat. No. 5,262,677, "Reactor Subsynchronous Tuning Scheme" by Ramirez discloses a passive device in combination with a line inductive shunt reactor. At synchronous frequency the device acts as a short circuit, allowing the current of this frequency to pass through, while at SSR frequencies, the device attains a selected admittance magnitude through the capacitance and shunt reactor. The disadvantages of using shunt reactors in transmission lines, though, are that various and undesirable steady-state losses are associated with each shunt reactor, and usually shunt reactors are very costly.
U.S. Pat. No. 5,343,381, "Electrical Dampening Circuit for Dampening Resonance of a Power Signal in a Power Distribution Network" by Bolduc et al. discloses a parallel filter circuit for dampening resonance of a power signal. Bolduc uses a simple RCL circuit tuned to filter out a certain range of frequencies. One disadvantage of having a simple filter circuit such as the Bolduc filter is that it is limited to dampening at that certain range of sub-synchronous frequencies, and may not filter out all of the damaging frequencies. Furthermore, losses of power at power frequency may occur.
Thus, there is a need in the art to provide a passive parallel filter that will not only produce less power losses at power frequency but will provide dampening at a wider range of sub-synchronous frequencies.

Sub-synchronous resonance filters for series capacitors


Disclosed is a phase change ink comprising: (a) an ink carrier comprising a compostable paraffin or polymethylene wax; and (b) a colorant.

Disclosed herein are phase change inks containing waxes. More specifically, disclosed herein are phase change inks containing paraffin or polymethylene waxes that undergo degradation by biological process during composting to yield carbon dioxide, water, inorganic compounds, and biomass at a rate consistent with other known compostable materials and leave substantially no visually distinguishable or toxic residues.
In general, phase change inks (sometimes referred to as "hot melt inks") are in the solid phase at ambient temperature, but exist in the liquid phase at the elevated operating temperature of an ink jet printing device. At the jet operating temperature, droplets of liquid ink are ejected from the printing device and, when the ink droplets contact the surface of the recording substrate, either directly or via an intermediate heated transfer belt or drum, they quickly solidify to form a predetermined pattern of solidified ink drops. Phase change inks have also been used in other printing technologies, such as gravure printing, as disclosed in, for example, U.S. Pat. No. 5,496,879 and German Patent Publications DE 4205636AL and DE 4205713AL, the disclosures of each of which are totally incorporated herein by reference.
Phase change inks are desirable for ink jet printers because they remain in a solid phase at room temperature during shipping, long term storage, or the like. In addition, the problems associated with nozzle clogging as a result of ink evaporation with liquid ink jet inks are largely eliminated, thereby improving the reliability of the ink jet printing. Further, in phase change ink jet printers wherein the ink droplets are applied directly onto the final recording substrate (for example, paper, transparency material, or the like), the droplets solidify immediately upon contact with the substrate, so that migration of ink along the printing medium is prevented and dot quality is improved.
Phase change inks frequently contain large amounts of non-compostable waxes, such as high molecular weight polyethylene waxes or the like, with such waxes often being present in phase change inks in amounts of about 50 percent by weight or more.
While known compositions and processes are suitable for their intended purposes, a need remains for improved phase change inks. In addition, a need remains for phase change inks with improved environmental friendliness. Further, a need remains for phase change inks containing an increased percentage of biodegradable and compostable components. Additionally, a need remains for phase change inks that exhibit improved performance in terms of ink rheology, print banding, filtration properties, jetting robustness, and/or thermal stability. There is also a need for phase change inks that can be prepared at reduced costs.


A method for a video encoder to encode video data into a video bit stream, the video data includes at least a picture, the picture includes a plurality of blocks, the method includes: receiving an available memory bandwidth value; determining an encoding type for the block according to the available memory bandwidth value; and encoding the block using the encoding type.

The present invention relates to a method and apparatus for encoding video signals, and more particularly, to a method and apparatus for adaptively adjusting the encoding type of video data to be encoded depending upon an available memory bandwidth for the video encoder.
As the operation speed of electronic components increases, video data processing, which consumes considerable computing resource of a system, becomes an important subject. In general, the video data processing standard provides various encoding types to support different requirements of video processing. For example, in the MPEG (moving picture experts group) 2 standard, a picture is compressed by eliminating spatial redundancies and temporal redundancies.
In general, there are some spatial similarities in chromatic, geometrical, or other characteristic values within a picture/image. In order to eliminate these spatial redundancies, it is required to identify significant elements of the picture and to remove the redundant elements that are less significant. For example, according to the MPEG 2 standard, a picture is compressed by eliminating the spatial redundancies by chrominance sampling, discrete cosine transform (DCT) and quantization. In addition, video data is actually a continuous series of pictures, which are perceived as a moving picture due to the persistence of pictures in the vision of human eyes. Since the time interval between pictures is very short, the difference between neighboring pictures is generally little and mostly appears in change of location of visual objects. Therefore, the MPEG 2 standard eliminates temporal redundancies caused by the similarity between pictures to further compress the video data.
In order to eliminate the temporal redundancies mentioned above, a process referred to as motion compensation is employed in the MPEG 2 standard. Before performing motion compensation, a current picture to be processed is typically divided into 16×16 pixel sized macroblocks (MB). For each current macroblock, a most similar prediction block of a reference picture is then determined by comparing the current macroblock with "candidate" macroblocks of a preceding picture or a succeeding picture. The most similar prediction block is treated as a reference block and the location difference between the current block and the reference block is then recorded as a motion vector. The above process of obtaining the motion vector is referred to as motion estimation. If the picture to which the reference block belongs is prior to the current picture, the process is called forward prediction. If the reference picture is posterior to the current picture, the process is called backward prediction. In addition, if the motion vector is obtained by referring both to a preceding picture and a succeeding picture of the current picture, the process is called bi-directional prediction. A common employed motion estimation method is a block-matching method. Additionally, because the reference block are probably not completely the same as the current block, it is required to calculate the difference between the current block and the reference block, which is also referred to as a prediction error. The prediction error is used for decoding the current block.
The MPEG 2 standard defines three encoding types to encode a picture: intra encoding, predictive encoding, and bi-directionally predictive encoding. An intra-coded picture (I-picture) is encoded independently without referring to a preceding picture or a succeeding picture. A predictive picture (P-picture) is encoded by referring to a preceding picture, where the preceding picture could be an I-picture or a P-picture. A bi-directionally predictive picture (B-picture) is encoded by referring to both a preceding picture and a succeeding picture.
Since no neighboring pictures are referred to when encoding an I-picture, less memory bandwidth is required. A reference picture is referred to when encoding a P-picture, so more memory bandwidth is required. Two reference pictures are referred to when encoding a B-picture, and therefore even more memory bandwidth is required.
A picture is composed of a plurality of macro-blocks, and the picture is encoded macro-block by macro-block. Each macro-block has a corresponding motion type parameter representing its motion compensation type. In the MPEG 2 standard, for example, each macro-block in the I-picture is intra-coded. The P-picture includes intra-coded and forward motion compensated macro-blocks. The B-picture may include intra-coded, forward motion compensated, backward motion compensated, and bi-directional motion compensated macro-blocks. As is well known in the art, an intra-coded macro-block is independently encoded without referring to other macro-blocks in a preceding picture or a succeeding picture. A forward motion compensated macro-block is encoded by referring to the forward prediction information of a most similar macro-block in the preceding picture. A bi-directional motion compensated macro-block is encoded by referring to the forward prediction information of a reference macro-block in the preceding picture and the backward prediction information of another reference macro-block in the succeeding picture.
As mentioned above, since the intra-coded macro-block is encoded without referring to other macro-blocks in the preceding picture or the succeeding picture, the required memory bandwidth while encoding an intra-coded macro-block is lower than other types of macro-block. While encoding the forward motion compensated macro-block, it is required to refer to a reference macro-block in the preceding picture so more memory bandwidth is required. Similarly, while encoding the bi-directional motion compensated macro-block, it is required to refer to both a reference macro-block in a preceding picture and another reference macro-block in a succeeding picture so it requires even more memory bandwidth.
In addition, the required memory bandwidth while encoding a macro-block not only relates to the encoding type but also relates to the motion estimation method employed thereof.
A conventional block-matching process of motion estimation is shown in FIG. 1. A current picture 120 is divided into blocks as shown in FIG. 1. Each block can be of any size. In the MPEG standard, for example, the current picture 120 is typically divided into macro-blocks with 16×16 pixels. Each block in the current picture 120 is encoded in terms of its difference from a block in a preceding picture 110 or a succeeding picture 130. During the block-matching process of a current block 100, the current block 100 is compared with similar-sized "candidate" blocks within a search range 115 of the preceding picture 110 or within a search range 135 of the succeeding picture 130. The candidate block of the preceding picture 110 or the succeeding picture 130 that is determined to have the smallest difference with respect to the current block 100, e.g. a block 150 of the preceding picture 110, is selected as a reference block. The motion vectors and residues between the reference block 150 and the current block 100 are computed and coded. As a result, the current block 100 can be restored during decompression using the coding of the reference block 150 as well as the motion vectors and residues for the current block 100.
A block-matching algorithm that compares the current block to every candidate block within the search range is called a "full search block-matching algorithm." In general, a larger search area produces a better motion vector. However, the required memory bandwidth of a full search block-matching algorithm is proportional to the size of the search area. For example, if a full search block-matching algorithm is applied on a macroblock of size 16×16 pixels over a search range of ±N pixels with one pixel accuracy, it requires (2×N+1)2 block comparisons. For N=16, 1089 16×16 block comparisons are required. Because each block comparison requires 16×16, or 256 calculations, this algorithm consumes considerable memory bandwidth and is computationally intensive.
FIG. 2 depicts a simplified schematic diagram of a video encoding/decoding system 10 according to the related art. The encoding/decoding system 10 includes a video encoder 12, a video decoder 14, an audio codec 16, a control unit 18, a memory management unit 20, a display controller 22, and a memory 24. As shown in FIG. 2, in the conventional encoding/decoding system 10, all components share the memory 24 via the memory management unit 20. Each of the video encoder 12, the video decoder 14, and the audio codec 16 would need to access the memory 24 via the memory management unit 20. The system memory could be an external DRAM located outside the video encoding device 10, and the memory management unit 20 could be a DRAM controller for accessing the external DRAM.
In order to overcome the disadvantages of the full search block-matching algorithm, a three-step hierarchical search algorithm is described by H. M. Jong et al. in "Parallel Architectures for 3-Step Hierarchical Search Block-Matching Algorithm," IEEE Trans. On Circuits and Systems for Video Technology, Vol. 4, August 1994, pp. 407-416. In a first stage, a coarse search is performed over a reasonably large area. In successive stages of a conventional hierarchical search, the size of the search area is reduced. For the same search range, the hierarchical search method uses less memory bandwidth and computations than the full search method but results in deterioration of the image quality.
In U.S. Pat. No. 5,731,850, Maturi et al. disclose a combination of the full search method and the hierarchical search method. The search range is determined according to the encoding type of the current picture. If the search range is larger than a threshold, the hierarchical search method is adopted to implement the block-matching process. If the search range is less than or equal to the threshold, the full search method is adopted to implement the block-matching process. In this way, the image quality and system performance are thereby balanced. Note that in the method of Maturi et al., the way to perform the block-matching process is dependent upon the size of the search range. However, if the system memory bandwidth is limited, when the required memory bandwidth of the video encoder is dramatically increased, the method of Maturi et al. cannot guarantee that the required memory bandwidth does not exceed the available memory bandwidth for the video encoder. As a result, the encoding performance is therefore decreased and the requirement of real-time encoding may not achieved due to the system memory not being capable of supporting such a high memory bandwidth.

Method and apparatus for encoding video signals


A system includes a heat exchanger mounted to the brackets and receiving cryogen, the heat exchanger having a vertical inlet coupled in parallel to a plurality of equal size horizontal tubes each traversing a width of the heat exchanger and further coupled in parallel to a vertical outlet pipe with an outlet diameter at least twice an inlet tube diameter; a temperature sensor; a thermostat that monitors the temperature sensor and maintains a predetermined temperature set point by communicating with a solenoid valve coupled to the heat exchanger; an exhaust line coupled to the outlet pipe that expels exhaust gas outside the enclosed facility; multiple fans attached to the heat exchanger; and a fail-safe oxygen sensor to protect a biological object in the enclosed facility.

There is a need in the computer industry to cool a room that is approaching critically hot temperatures. The room, filled with thousands of disk drives, known as server farms, becomes excessively hot because of the heat energy from the electronics. The facility air conditioning system will typically keep the temperature to an acceptable level. But under extreme circumstances, such as at peak use times on a hot summer day, and especially when the power company institutes brown outs, the facility is in danger of reaching high temperatures that will damage the electronic equipment. Equipment shutdowns are very costly and disappoint customers, who expect uninterrupted service.