A photoconductor that includes, for example, a backing layer, a supporting substrate, a photogenerating layer, and a charge transport layer, and where the outermost layer of the backing layer is comprised of a mixture of a glycoluril resin and a polyol resin.

Curl occurs in layered photoreceptors primarily since each layer has a different thermal contraction coefficient, or due to shrinkage during the fabrication process. In particular, the charge transport layer usually has a higher contraction coefficient than the photoconductor supporting substrate. In forming the imaging member, the charge transport layer may be formed from a solution, which is then heated or otherwise dried. As a result of the aforementioned mismatch, the higher contraction coefficient causes the imaging member to curl as the imaging member cools from the higher drying temperature down to ambient temperature. The anticurl backside coating (ACBC) layer is applied to flatten, or substantially flatten the substrate.
In embodiments, the photoconductors disclosed herein include an ACBC layer on the reverse side of the supporting substrate of a belt photoconductor. The ACBC layer, which can be solution coated, such as for example, as a self-adhesive layer on the reverse side of the substrate of the photoreceptor, may comprise a number of suitable materials such as those components that may not substantially effect surface contact friction reduction and prevents or minimizes wear/scratch problems for the photoreceptor device. In embodiments, the mechanically robust ACBC layer of the present disclosure usually will not substantially reduce the layer's thickness over extended time periods to adversely effect its anticurling ability for maintaining effective imaging member belt flatness, for example when not flat, the ACBC layer may, but not necessarily will, cause undesirable upward belt curling which adversely impacts imaging member belt surface charging uniformity causing print defects which thereby prevent the imaging process from continuously allowing a satisfactory copy printout quality; moreover, ACBC wear also produces dirt and debris resulting in dusty machine operation condition. Since the ACBC layer is located on the reverse side of the photoconductor, it does not usually adversely interfere with the xerographic performance of the photoconductor, and decouples the mechanical performance from the electrical performance of the photoconductor.
Moreover, high surface contact friction of the ACBC layer against the machine, such as printers, subsystems can cause the development of undesirable electrostatic charge buildup. In a number of instances with devices, such as printers, the electrostatic charge builds up because of high contact friction between the ACBC layer and the backer bars, which increases the frictional force to the point that it requires higher torque from the driving motor to pull the belt for effective cycling motion. In a full color electrophotographic apparatus, using a 10 pitch photoreceptor belt, this electrostatic charge build-up can be high due to the large number of backer bars used in the machine.
Additionally, in embodiments the disclosed ACBC layers possess antistatic characteristics, and a tunable resistivity where, for example, the resistivity of the ACBC layer can be controlled and changed gradually depending, for example, on the glycoluril resin/polyol resin ratio amount selected. Thus, for example, the surface resistivity of the ACBC layer increased from about 1011 to about 1013 ohm/sq when the glycoluril resin/polyol resin ratio varied from about 2/1 to about 1/2. Further, primarily in view of the crosslinked resin ACBC layer mixture nature where the crosslinking percentage densities vary and can be, for example, of from about 50 to about 100 percent, from about 70 to about 95 percent, from about 60 to about 90 percent, from about 75 to about 100 percent, the ACBC layer exhibited excellent adhesion, and substantially no peeling to substrates, such as the PEN substrate of Example I, and with a polymer like a polycarbonate (PC) selected as the overcoat on the photoconductor ACBC layer, no or minimal peel resulted, and also where the overcoat is scratch resistant and solvent resistant.
A conductive ACBC layer enables, for example, the elimination of an active power supply used to discharge the back of the belt in a xerographic printing apparatus thereby resulting in a cost savings. When backer bars are inadvertently cleaned with certain solvents like methanol, the polarity of the triboelectrically generated (or friction generated) charge changes and the discharge power supply actually adds charge to the belt (it can only operate with one polarity) creating high drag forces and belt steering issues, a disadvantage eliminated with the ACBC containing photoconductor of the present disclosure.
The present disclosure relates generally to electrophotographic imaging members, inclusive of photoconductors. More specifically, the present disclosure relates to photoconductors having enhanced durability, and as compared to a known polytetrafluoroethylene doped ACBC layer, a slippery surface, a higher bulk conductivity and excellent mechanical wear characteristics, and where the ACBC layer is located on the side of the substrate opposite that of the imaging layers. Also, the ACBC layer of the present disclosure possesses in embodiments resistance to airborne chemical contaminants, which can decrease the photoconductor service life. Typical chemical contaminants include solvent vapors, environment airborne pollutants, and corona species emitted by machine charging subsystems such as ozone. Further, the photoconductor in a xerographic system is subjected to constant mechanical interactions against various subsystems.
The ACBC layer in this disclosure can be a two layer or single layer structure. In the two layer structure, the bottom layer adjacent to the substrate provides anticurl functionality, and the top layer adjacent to the bottom layer provides wear resistance, slippery surface, and antistatic properties.

Resin mixture backing layer containing photoconductor


The invention discloses a population of selected permeability microcapsule particles comprising an oil soluble or dispersible core material and a wall material at least partially surrounding the core material. The microcapsule wall material comprises the reaction product of a first composition in the presence of a second composition comprising an anionic emulsifier. The first composition comprises a reaction product of i) an oil soluble or dispersible amine with ii) a multifunctional acrylate or methacrylate monomer or oligomer, an oil soluble acid and an initiator. The anionic emulsifier comprises a water soluble or water dispersible acrylic acid alkyl acid copolymer, an optional initiator and an alkali or alkali salt. The reaction product of the first composition and second composition can result in the formation of a low permeability microcapsule wall. Optionally, one or both of the first composition initiator or water phase initiator is an energy-activated initiator, such as a UV initiator. The reaction can proceed by exposing the respective compositions to actinic radiation. Microcapsules of selected permeability can be produced by the process of the invention.

1. Field of the Invention
This invention relates to capsule manufacturing processes and microcapsules produced by such processes.
2. Description of the Related Art
Various processes for microencapsulation, and exemplary methods and materials are set forth in Schwantes (U.S. Pat. No. 6,592,990), Nagai et. al. (U.S. Pat. No. 4,708,924), Baker et. al. (U.S. Pat. No. 4,166,152), Wojciak (U.S. Pat. No. 4,093,556), Matsukawa et. al. (U.S. Pat. No. 3,965,033), Matsukawa (U.S. Pat. No. 3,660,304), Ozono (U.S. Pat. No. 4,588,639), Irgarashi et. al. (U.S. Pat. No. 4,610,927), Brown et. al. (U.S. Pat. No. 4,552,811), Scher (U.S. Pat. No. 4,285,720), Shioi et. al. (U.S. Pat. No. 4,601,863), Kiritani et. al. (U.S. Pat. No. 3,886,085), Jahns et. al. (U.S. Pat. Nos. 5,596,051 and 5,292,835), Matson (U.S. Pat. No. 3,516,941), Chao (U.S. Pat. No. 6,375,872), Foris et. al. (U.S. Pat. Nos. 4,001,140; 4,087,376; 4,089,802 and 4,100,103), Greene et. al. (U.S. Pat. Nos. 2,800,458; 2,800,457 and 2,730,456), Clark (U.S. Pat. No. 6,531,156), Saeki et. al. (U.S. Pat. Nos. 4,251,386 and 4,356,109), Hoshi et. al. (U.S. Pat. No. 4,221,710), Hayford (U.S. Pat. No. 4,444,699), Hasler et. al. (U.S. Pat. No. 5,105,823), Stevens (U.S. Pat. No. 4,197,346), Riecke (U.S. Pat. No. 4,622,267), Greiner et. al. (U.S. Pat. No. 4,547,429), and Tice et. al. (U.S. Pat. No. 5,407,609), among others and as taught by Herbig in the chapter entitled "Encapsulation" in Kirk Othmer, Encyclopedia of Chemical Technology, V.13, Second Edition, pages 436-456 and by Huber et. al. in "Capsular Adhesives", TAPPI, Vol. 49, No. 5, pages 41A-44A, May 1966, all of which are incorporated herein by reference.
More particularly, U.S. Pat. Nos. 2,730,456, 2,800,457; and 2,800,458 describe methods for capsule formation. Other useful methods for microcapsule manufacture are: U.S. Pat. Nos. 4,001,140; 4,081,376 and 4,089,802 describing a reaction between urea and formaldehyde; U.S. Pat. No. 4,100,103 describing reaction between melamine and formaldehyde; British Pat. No. 2,062,570 describing a process for producing microcapsules having walls produced by polymerization of melamine and formaldehyde in the presence of a styrenesulfonic acid. Forming microcapsules from urea-formaldehyde resin and/or melamine formaldehyde resin is disclosed in U.S. Pat. Nos. 4,001,140; 4,081,376, 4,089,802; 4,100,103; 4,105,823; and 4,444,699. Alkyl acrylate-acrylic acid copolymer capsules are taught in U.S. Pat. No. 4,552,811. Each patent described throughout this application is incorporated herein by reference to the extent each provides guidance regarding microencapsulation processes and materials.
Interfacial polymerization is a process wherein a microcapsule wall of a polyamide, an epoxy resin, a polyurethane, a polyurea or the like is formed at an interface between two phases. U.S. Pat. No. 4,622,267 discloses an interfacial polymerization technique for preparation of microcapsules. The core material is initially dissolved in a solvent and an aliphatic diisocyanate soluble in the solvent mixture is added. Subsequently, a nonsolvent for the aliphatic diisocyanate is added until the turbidity point is just barely reached. This organic phase is then emulsified in an aqueous solution, and a reactive amine is added to the aqueous phase. The amine diffuses to the interface, where it reacts with the diisocyanate to form polymeric polyurethane shells. A similar technique, used to encapsulate salts which are sparingly soluble in water in polyurethane shells, is disclosed in U.S. Pat. No. 4,547,429. U.S. Pat. No. 3,516,941 teaches polymerization reactions in which the material to be encapsulated, or core material, is dissolved in an organic, hydrophobic oil phase which is dispersed in an aqueous phase. The aqueous phase has dissolved materials forming aminoplast resin which upon polymerization form the wall of the microcapsule. A dispersion of fine oil droplets is prepared using high shear agitation. Addition of an acid catalyst initiates the polycondensation forming the aminoplast resin within the aqueous phase, resulting in the formation of an aminoplast polymer which is insoluble in both phases. As the polymerization advances, the aminoplast polymer separates from the aqueous phase and deposits on the surface of the dispersed droplets of the oil phase to form a capsule wall at the interface of the two phases, thus encapsulating the core material. This process produces the microcapsules. Polymerizations that involve amines and aldehydes are known as aminoplast encapsulations. Urea-formaldehyde (UF), urea-resorcinol-formaldehyde (URF), urea-melamine-formaldehyde (UMF), and melamine-formaldehyde (MF), capsule formations proceed in a like manner. In interfacial polymerization, the materials to form the capsule wall are in separate phases, one in an aqueous phase and the other in a fill phase. Polymerization occurs at the phase boundary. Thus, a polymeric capsule shell wall forms at the interface of the two phases thereby encapsulating the core material. Wall formation of polyester, polyamide, and polyurea capsules typically proceeds via interfacial polymerization.
U.S. Pat. No. 5,292,835 teaches polymerizing esters of acrylic acid or methacrylic acid with polyfunctional monomers. Specifically illustrated are reactions of polyvinylpyrrolidone with acrylates such as butanediol diacrylate or methylmethacrylate together with a free radical initiator.
Common microencapsulation processes can be viewed as a series of steps. First, the core material which is to be encapsulated is typically emulsified or dispersed in a suitable dispersion medium. This medium is typically aqueous but involves the formation of a polymer rich phase. Most frequently, this medium is a solution of the intended capsule wall material. The solvent characteristics of the medium are changed such as to cause phase separation of the wall material. The wall material is thereby contained in a liquid phase which is also dispersed in the same medium as the intended capsule core material. The liquid wall material phase deposits itself as a continuous coating about the dispersed droplets of the internal phase or capsule core material. The wall material is then solidified. This process is commonly known as coacervation.
Capsules made according to the invention can be made to better control permeability characteristics. Capsules made according to the invention are surprisingly better able to contain liquid contents without leakage over time. The capsules can be made less leaky than those made by comparable prior art processes.
The capsules according to the invention are useful with a wide variety of capsule contents ("core materials") including, by way of illustration and without limitation, internal phase oils, solvent oils, dyes, perfumes, fragrances, cleaning oils, polishing oils, flavorants, sweeteners, chromogens, pharmaceuticals, fertilizers, herbicides, scents, and the like. The microcapsule core materials can include materials which alter rheology or flow characteristics, or extend shelf life or product stability. Essential oils as core materials can include, for example, by way of illustration wintergreen oil, cinnamon oil, clove oil, lemon oil, lime oil, orange oil, peppermint oil and the like. Dyes can include fluorans, lactones, indolyl red, I6B, leuco dyes, all by way of illustration and not limitation. The core material should be dispersible or sufficiently soluble in the capsule internal phase material namely in the internal phase oil or soluble or dispersible in the monomers or oligomers solubilized or dispersed in the internal phase oil. The core materials are preferably liquid but can be solid depending on the materials selected, and with temperatures appropriately adjusted to effect dispersion.
Low capsule permeability is a sought after characteristic of microcapsules for many applications. Although various microencapsulation processes are known, a need has existed in particular for lower permeability and more durable capsules.
Conventional techniques for capsule rupture include pressure, scraping, friction, shearing, impact, or other energy input such as rapid temperature gradient such as provided by laser impingement.
The low permeability characteristics of the capsules disclosed herein have usefulness for a variety of applications. The internal phase can be held securely over time but available to be exuded or released upon fracture or breakage of the capsules such as with application of pressure, ultrasonics, tearing forces, scraping, or friction. Heat rupture, thermal shock or other energy input can also be used to release the core contents.


A power generation system includes a power module and an external process module. The external process module may include at least one engine support element. The power module has at least one connection zone, and the external process module has at least one connection zone that is configured to align with the at least one connection zone of the power module. The aligned connection zones of the power module and the external process module permit relatively quick and inexpensive attachment of the external process module to the power module. The at least one engine support element may be an aftertreatment element.

In recent years regulatory agencies around the world have instituted changes in the regulations governing the emission levels of power generation systems. The changing of these regulations has resulted in many manufacturers of power generation systems producing aftertreatment systems to be added to their power generation systems. These aftertreatment systems reduce the levels of regulated emissions produced by the power generation systems. However, the process of adding the aftertreatment systems to the power generation systems has revealed several problems.
The typical process of attaching aftertreatment systems to power generation systems involves attaching individual elements of the aftertreatment system to the housing of the power generation system. However, a typical aftertreatment system includes several aftertreatment elements that each must be attached to the power generation system. Therefore, several laborers must travel to the site where the power generation system is located, determine the proper location for each aftertreatment element, prepare the power generation system for the attachment of the aftertreatment elements, attach each aftertreatment element to the power generation system, and connect the aftertreatment elements to each other and to the exhaust of the power generation system. This process is both time consuming and expensive.
When an aftertreatment system is to be added to a portable power generation system, other difficulties arise. The top sides of the housings of most portable power generation systems are not strong enough to support the weight of an aftertreatment system. Therefore, a typical procedure for attaching an aftertreatment system to a portable power generation system includes attaching supporting members to a side of the housing of the portable power generation system. These supporting members typically have one end welded to the base of the housing, a body that extends vertically up the side of the housing, and another end that extends above the top side of the housing. The aftertreatment elements are then attached to these members. Adding these supporting members to the housing increases the time and expense required to install the aftertreatment system.
Transportation problems are also inherent in the current method of adding aftertreatment systems to power generation systems. Individual aftertreatment elements are not easily transported via typical shipping methods. In addition, when supporting members are added to the housings of portable power generation systems, the supporting members add width and/or length to the housings. Therefore, these modified housings are often too large to be shipped via conventional means. In fact, special permits are often required to transport such modified housings on highways.
U.S. Pat. No. 4,992,669 issued to Parmley on Feb. 12, 1991 discloses a modular energy system in which a driven unit is connected to a driving unit via a shaft. These modular units are attached to each other via locking assemblies. However, the units that are shown in the '669 patent are each the same size. Stacking such units on top of each other could result in wind loads on the system of sufficient strength to cause damage to the system. In addition, the driven units in the '669 patent do not provide support for internal engine processes but merely use the power created by the driving units.

Power generation system having an external process module


An operation lever is rotatable in a vertical rotation direction about a vertical rotation shaft and rotatable in a front-rear rotation direction about a front-rear rotation shaft non-parallel to the vertical rotation shaft. An urging portion urges the operation lever to move to a predetermined initial position. A neutral cam portion rotates following a rotation of the operation lever in the vertical rotation direction; a forward/backward cam portion rotates following a rotation of the operation lever in the front-rear rotation direction; a neutral switch portion is pressed by the neutral cam portion and detects the pressing in a state where the neutral cam portion is rotated to a neutral pressing position; and a forward/backward switch portion is pressed by the forward/backward cam portion and detects the pressing in a state where the forward/backward cam portion is rotated to a forward pressing position or a backward pressing position.

Conventionally, a technique of an operation device capable of switching a transmission of a work vehicle is known. For example, the technique is described in JP 2005-343220 A.
JP 2018-188080 A describes a shift operation device capable of performing an operation of switching a transmission mechanism of a tractor among forward, reverse, and neutral. The shift operation device is capable of switching a transmission by moving an operation tool to a desired shift position.
In the shift operation device described in JP 2018-188080 A, after the operation tool is moved to the desired shift position, the operation tool is held in a state where the operation tool is positioned at the desired shift position.
Here, in a tractor, a configuration in which a plurality of shift operation devices are provided in a driver's seat is conceivable. In this case, in the configuration in which the operation tool is held at the desired shift position as in the shift operation device described in JP 2018-188080 A, in a case where the transmission mechanism is switched based on an operation of another shift operation device, there is a possibility that the operation may be complicated among a plurality of shift operation devices. Therefore, improvement in operability has been demanded.


A zero anticipation mechanism for an arithmetic unit 42 of a processing engine includes an array of cells 420, 430 interconnected to produce an ordered sequence of intermediate anticipation signals. The array of cells includes cells connected to receive intermediate result signals from the arithmetic unit, cells for forwarding an intermediate anticipation signal supplied thereto, and cells for generating a combination of first intermediate anticipation signals and second intermediate anticipation signals supplied thereto. The zero anticipation mechanism implements a zero look-ahead mechanism which can predict a zero result 479 prior to the arithmetic unit completing an arithmetic operation.

This application claims priority to S.N. 98402457.0, filed in Europe on Oct. 6, 1998 and S.N. 98402455.4, filed in Europe on Oct. 6, 1998.
The present invention relates to zero anticipation in the field of computing systems. In particular, the invention relates to a zero anticipation mechanism, to a processing engine and a computing system including such a mechanism and to a method of zero anticipation in such apparatus.
Where reference is made to a computing system, it should be understood that this term is intended to relate generally to systems and apparatus which perform computations, including computers and electronic apparatus including processing engines for performing computations, and to the processing engines themselves. Many different types of processing engines are known, including the central processing units of mainframe systems, microprocessors, micro-controllers, digital signal processors and so on.
The performance of a computing system is vitally affected by the speed and accuracy with which arithmetic operations are performed in the processing engine. This is because many of the instructions executed by a processing engine of such a computing system require arithmetic operations. Arithmetic circuitry is often the most complex circuitry in the instruction execution unit of a processing engine in terms of the number of gates and logic levels. In relative terms, therefore, arithmetic operations tend to be slow and prone to error. One important aspect of the result of arithmetic operations is the determination of condition codes.
A condition code will be set by the processing engine to reflect the outcome of an arithmetic operation. This code assists the processing engine in making operational decisions which depend upon arithmetic results. A typical processing engine, such as a microprocessor or a digital signal processor for example, has an arithmetic logic unit (ALU) which performs mathematical operations on two or more xe2x80x9cNxe2x80x9d bit operands, where xe2x80x9cNxe2x80x9d represents the total number of bits per operand. It will be convenient in the following to refer to the xe2x80x9cixe2x80x9dth bit, where xe2x80x9cixe2x80x9d is an index variable whose value is between 0 and Nxe2x88x921 inclusive.
One type of computation result on which a decision, such as for example branch decision, might be made is where the operation result is a zero condition. For example, a branch might be made if the result of a computation is zero, whereas program execution might otherwise continue at the next command. Alternatively, the converse may be true.
Typically, the decision as to whether to take a branch or not will rely on the resolution of the computation result (e.g., whether the result is zero or not). As, however, this may take some time and, also, the branch operation itself will take some time, this can have a not insignificant effect on overall system performance.
Condition codes are also important in some non-arithmetic operations, for example a conditional data operation where the destination of a result will depend upon the resolution of the condition. An example of this could, for example, be a data load instruction involving the generation of data complements. Once again, the time taken to resolve the condition and then to effect the operation dependent thereon can have a not insignificant effect on performance.
The condition code may, for example, be employed to indicate that the result of an operation is greater than zero (GT), less than zero (LT), or equal to zero (EQ). LT is the easiest outcome to detect, because it simply involves examining the sign bit of the result. In general, GT and EQ are more difficult outcomes to detect, because the sign bit of the result is set positive when the result is either zero or a positive quantity. Therefore, examining the sign bit of the result, when the result is equal to zero, does not indicate whether the result is zero or a positive number. However, for the result of a specific instruction on specific data, EQ and GT are mutually exclusive. Thus, determining one is sufficient for the determination of the other, once LT has been excluded.
In adder operation, the traditional method of determining when the result is zero is to NOR all of the output bits of an adder circuit to reduce as fast as possible the output bits to a single output (zero) using a binary tree. However, as many architectures require 32-bit, or wider, data path for fixed point units, they also require adders of 32 bits in width. The NORing all of the output bits may require two or more additional stages of logic, depending on the technology used for implementation. For example, to reduce 32 bits would take five stages with two input NOR gates (25=32) and three stages with four input NOR gates (43=64). As higher clock rates are demanded, the addition of logic stages to an adder circuit can result in the condition code becoming critical, thereby forcing completion of its computation into the next machine cycle.
Several solutions have been proposed for determining when a result is zero. For example, U.S. Pat. No. 4,924,422 issued May 8, 1990 to IBM Corporation describes a method and apparatus for determining when a result is zero. This patent determines when two operands are equivalent directly from the operand without the use of an adder. In one embodiment, conditions for the sum being equal to zero are determined from half sum to carry and transmit operators derived from the input operands. These operands are used in some known types of adders and, thus may be provided from a parallel adder to the condition prediction circuitry. In another embodiment, the equations for a carry-save-adder are modified to provide a circuit specifically designed for the determination of the condition when the sum of the operands is equal to zero. This sum is equal to zero circuit reduces the gate delay and gate count allowing the processor central processing unit to determine the condition prior to the actual sum of two operands. This allows the processing engine to react to the condition more quickly, thus increasing overall operating speed.
U.S. Pat. No. 4,815,019, issued Mar. 21, 1989 to Texas Instruments, Inc., describes a method and apparatus for determining when an ALU result is zero. This patent describes a fast ALU=0 circuit that is used with a carry-select look ahead ALU. Preliminary ALU=0 signals are derived for each section of the ALU prior to a carry in signal being received by that section. When the carry in signal is received, a final comparison is made with the least significant bit of the section and the final ALU=0 signal is generated. The ALU=0, computation is completed one gate delay after the ALU computation is completed. The circuit for computing whether the result of an ALU computation is zero determines whether certain bits are zero before the ALU computation is complete. When the final ALU computation is available, only a very small number of bits need be considered to determine whether the result is zero. This determination is made with the insertion of only 1 additional gate delay after the ALU computation is complete.
U.S. Pat. No. 5,508,950, issued Apr. 16, 1996 to Texas Instruments, Inc., describes a circuit and method for detecting when an ALU result is zero. This patent describes a circuit and method for detecting if a sum of a first multi-bit number A of N bits and a second multi-bit number B of N bits equals a third multi-bit number C of N bits prior to availability of the sum of A and B. A propagate signal, a generate signal and a kill signal are generated for each bit in the proposed sum. A zero signal is formed from these signals. The particular manner of forming the zero signal for each bit depends upon the state of the third multi-bit number C for the corresponding bit and the prior bit. The zero signal is an exclusive OR of the corresponding propagate signal Pn and a kill signal Knxe2x88x921 of a prior bit if the current bit and the prior bit of C are xe2x80x9c00xe2x80x9d. The zero signal is an exclusive NOR of the corresponding propagate signal Pn and a generate signal Gnxe2x88x921 of a prior bit if the current bit and the prior bit of C are xe2x80x9c01xe2x80x9d. The zero signal is an exclusive NOR of the corresponding propagate signal Pn and a kill signal Knxe2x88x921 of a prior bit if the current bit and the prior bit of C are xe2x80x9c10xe2x80x9d. The zero signal is an exclusive OR of the corresponding propagate signal Pn and a generate signal Gnxe2x88x921 of a prior bit if the current bit and the prior bit of C are xe2x80x9c11xe2x80x9d. The sum of A and B equals C if all the zero signals are active xe2x80x9c1xe2x80x9d. The propagate signal, generate signal and kill signal of the various bits can be used to form the sum. This technique provides the equality signal before the carry can ripple through the adder logic.
Accordingly, an aim of the present invention is to provide an improved mechanism and method for determining a zero condition, whereby operational speed of a processing engine of computing system may be increased.
Particular and preferred aspects of the invention are set out in the accompanying independent and dependent claims. Combinations of features from the dependent claims may be combined with features of the independent claims as appropriate and not merely as explicitly set out in the claims.
In accordance with a first aspect of the invention, there is provided a zero anticipation mechanism for an arithmetic unit of a processing engine. The zero anticipation mechanism comprises an array of cells interconnected to produce an ordered sequence of intermediate anticipation signals. The array of cells includes cells connectable to receive intermediate result signals from the arithmetic unit, cells for forwarding an intermediate anticipation signal supplied thereto and cells for generating a combination of a first intermediate anticipation signal and a second intermediate anticipation signal supplied thereto.
An embodiment of the invention can predict when the result of an arithmetic unit is zero before the result is available. The array of cells derives an algebraic or logical combination of intermediate result signals from an arithmetic unit to predict, or anticipate a zero result not later than the result is available.
In an embodiment of the invention, the array of cells can be arranged in an array with the cells selectively interconnected in first and second directions. The cells can have one or more of: a first input for connection to the output of an adjacent cell in the first direction; a first output for connection to an input of an adjacent cell in the first direction; a second input for connection to the output of an adjacent cell in the second direction; and a second output for connection to an input of an adjacent cell in the second direction.
Different cells in the array have different combinations of inputs and outputs according to their position in the array. A cell with a first input and a first output is operable to transmit a signal received at the first input to the first output without adding delay. A cell for forwarding an intermediate anticipation signal and having a second input and a second output is operable to buffer a signal received. at the second input for a predetermined time prior to forwarding the signal from the second output. A cell for forwarding an intermediate anticipation signal and having a second input and a second output is operable to buffer a signal received at the second input for a predetermined time prior to forwarding the signal from the second output. A cell for combining intermediate anticipation signals supplied thereto and having a first input, a second input and at least one of a first output and a second output is operable to combine an intermediate anticipation signal received at the first input with an intermediate anticipation signal received at the second input and to output the combined intermediate anticipation signal from at least one output. The combination can be a logical combination of the input signals. The logical combination can be defined by an operator u, such that:
(g_1, p_1, z_1)u(gxe2x80x94r, pxe2x80x94r, zxe2x80x94r)=(g_1+(p_1xc2x7gxe2x80x94r), p_1xc2x7pxe2x80x94r,(z_1xc2x7zxe2x80x94rxc2x7(xcx9cgxe2x80x94r))+p_1xc2x7zxe2x80x94rxc2x7gxe2x80x94r),
where g_1 and g_r are first and second generate terms, p_1 and pxe2x80x94r are first and second propagate terms, z_1 and z_r are first and second zero anticipation terms.
In an embodiment of the invention, a zero anticipation mechanism for an arithmetic unit providing an arithmetic result having N bits ordered from a lowest bit position to a highest bit position includes a plurality of sub-arrays. Each sub-array is associated with a respective group of adjacent bit positions of the arithmetic result and generates an intermediate anticipation result signal. The intermediate anticipation result signal of a sub-array is forwarded directly to all sub-arrays associated with higher order bit positions.
A global, or final output of a sub-array associated with a highest order bit position forms a zero anticipation signal.
An intermediate zero anticipation signal may also be provided from a sub-array associated with an intermediate bit position. This can provide an intermediate zero anticipation result in respect of bits up to an including the intermediate bit position.
An embodiment of the invention can be implemented for an arithmetic unit operable to perform an arithmetic operation on operands A and B, where each operand comprises an ordered sequence of N bits, A(i) and B(i), respectively, for i=0 to Nxe2x88x921, which includes a carry look-ahead adder for generating the result of the arithmetic operation. In such an implementation, the array of cells can be formed by cells of the carry look-ahead adder.
The arithmetic unit can include a carry-save adder responsive to operands A and B for producing an ordered sequence of intermediate result signals by carry-free combination of operand A with operand B. The zero anticipation mechanism can be connectable to the carry-save adder circuit for generating a zero anticipation signal based on an algebraic combination of carry-in signals from the carry-save adder with the ordered sequence of intermediate result signals for anticipating a zero magnitude result, with the zero anticipation output being generated not later than the result.
In accordance with another aspect of the invention, there is provided a processing engine including an arithmetic unit for providing an arithmetic result and a zero anticipation mechanism as set out above.
Examples of possible types of arithmetic unit are a multiply and accumulate unit, a floating point unit and, more generally any arithmetic and logic unit.
The processing engine could, for example, be a digital signal processor.
In accordance with further aspect of the invention, there is provided an integrated circuit comprising a processing engine as set out above.
In accordance with yet another aspect of the invention, there is provided a a method of anticipating a zero result of an arithmetic unit of a processing engine. The method comprises:
providing input data to the arithmetic unit,
generating intermediate result signals for the arithmetic unit; and
producing an ordered sequence of intermediate anticipation signals by receiving the intermediate result signals from the arithmetic unit to form intermediate anticipation signals, and selectively forwarding and combining intermediate anticipation signals in accordance with a predetermined algorithm for generating a zero anticipation signal.


This invention disclose a process for producing a multi-layer biaxially oriented polypropylene synthetic paper of improved gloss and easy-drying printability by means of 3-layer co-extrusion wherein two different PP resin composites are separately extruded by one primary and two secondary extruders and then co-flowed by a same T-die to form a paper sheet having three layer coating material sheet, and through cooling, bi-axial orientation, surface-coating by prime coating and top coating, winding and calendering to be a synthetic paper depending on the required thickness.

Nowadays the paper made of natural pulp is replaced with the polyolefin synthetic paper mainly comprising the basic substrate layer (intermediate Layer) in the intermediate Layer called biaxially oriented polypropylene (hereinafter, abbreviated as BOPP), whereon the back surface is laminated with the uniaxially oriented polypropylene (UOPP) containing inorganic fine powder as the paper surface layer (such as the Japanese Patent publication No. 40794/71, Japanese Laid-open Publication No. 141339/81). Moreover, for improving gravure printability, coating composition comprising liquid acrylic copolymer and polyethyleneimine can be coated onto the surface to give 0.005-0.1 gIm.sup.2 (the Japanese Laid-open Publication No. 10624/75, No. 161478/75); The Japanese Laid-open Publication No. 87255/91 discloses a composite film of opacity over 90% made from a biaxially oriented polymer film to serve as a substrate layer (intermediate layer) which is formed by resin composition of high crystallinity polypropylene in isotacticity over 98% of 35-95% weight and talc and/or mica powder of 5-65% weight, and a uniaxially oriented polymer film adhered hereonto at least one surface of the intermediate layer by resin composition of high crystallinity polypropylene in isotacticity over 98% of 20-90% weight and inorganic filler powder in 10-80% weight.
Such a synthetic paper can contact closely with printing head, and provides the merits of rigidity-mechanical strength, but leaves the drawbacks on the ink drying speed. The amount and crosslinking of synthetic paper pore is inferior to that of cultural paper. As a result, printing ink takes quite a long time before completely dried, that is why it is unsuitable for cultural paper (in the case of 4-colour printing it takes 8 hours for drying). Also, the amount of stacking is limited to prevent unneeded reverse printing. Thus, it will increase the man-hours and space for drying in the 4-color printing process. Furthermore, due to the surface layer is the uniaxially oriented polypropylene firm containing inorganic fine filler, poor transfer of ink upon offset printing often occurs in multicolor continuous offset printing and also in both surface printing.
This poor ink adhesiveness must be improved by increasing the ink outlet to reach the required color saturation. Meanwhile, to avoid the deformation of paper surface and the variation of paper dimension by the ink solvent, the specific ink is used for printing which is 3-4 times price of those used in the natural paper.
These drawbacks mentioned above specify the different expense during the printing process between the uniaxial oriented polypropylene synthetic paper and the natural paper also explain why the natural paper can not be replaced in various uses.
Nissin textile Company (Japan) produces the synthetic paper by forming a layer with surface treatment in the extensible or non-extensible films of PP, polyvinyl chloride, Polystyrene, and Polyester. The properties on dryness and printability of the afore paper though are far better than those of the uniaxial oriented PP synthetic paper containing inorganic filler. In general conception, it should be able to replace the natural paper extensively. As a matter of fact, this synthetic paper costs higher than those of various items of natural paper Accordingly, its market sale is inferior to that of the uniaxial oriented PP synthetic pa-containing inorganic filler. In its manufacturing process, it utilizes DMF as the solvent for the surface treatment, and causes a large amount of poison water, which subsequently demands a costly investment for dealing with poisonous drainage to prevent great detriment to environment. In addition, the reverse coater required for using the DMF solvent system will cause a quite thick paper layer (about 30.mu. for general type and 10-20.mu. for special product use), not available for coating layer under 10.mu. with excellent paper surface quality.
The aforesaid factors will certainly increase the cost (such as materials, facilities) during the coating process, as a result, not suitable for extensively adopting synthetic paper to replace of natural paper except for some specific use.
In order to produce a low-cost synthetic paper without drawbacks mention above to be able to extensively replace of natural paper in cultural paper use, the applicant had spent quite a long time for thinking, and finally got a Taiwanese patent, No. 85100270, which mainly use a method such as co-extrusion in which the different melts of polymers are extruded from one primary extruder and two secondary extruders separately prior to extruding them simultaneous through a single main "T" die for forming a three-layer sheet and then through cooling and shaping, biaxially orientation, electric halo treatment and laminating/rolling to be a synthetic paper with required thickness. At last, surface treatment for coating on the paper surface obtains a biaxially oriented PP synthetic paper of easy drying printability.
The synthetic paper made from the method of Taiwanese patent No. 85100270 is almost the same as art paper in using of kind and amount of inks, the dryness and quality of printings, and the amount and crosslinking of minute pore. Its some features are superior to traditional paper, but the surface gloss and the color vividness are inferior to them. The original surface of art paper is rugged which is required for pressed several times for smoothing.
In order to solve the drawbacks for being unable to raise up the gloss of paper, quality of surface and its printings, and the problem for the big loss of paper thickness during the foggy facing process of art paper which prevents the endeavor for the improvement of paper ruggedness (now, the best ruggedness of paper in the world is 0.8-0.9.mu.), the applicant of present invention experienced a number of experiments trying to figure out a different way not only from the existing arts but better than them. The applicant finally creates the invention which provides merits over traditional synthetic papers in product cost, quality (such as surface gloss, printing gloss, ink drying speed), and over art paper in specific gravity, surface ruggedness, and printing resolution.

Process for the production of a biaxially oriented polypropylene synthetic paper of high gloss and easy-drying printability


A wireless network device and a communication method using the wireless network device are provided to simplify an association process of the device moving over different wireless networks and to enhance mobility of the device. The wireless network device includes an allocater allocating a device identifier (ID) to a predetermined device, an information generator generating information on the allocated device ID, and a first controller generating a packet containing the generated device ID and transmitting the generated packet to another wireless network.

1. Field of the Invention
The present invention relates to a wireless network device and a communication method using the wireless network device, and more particularly, to a wireless network device and a communication method using the wireless network device designed to simplify an association process of the device moving over the wireless networks and to enhance mobility of the device.
2. Description of the Related Art
With advancements in communication and network technologies, a wired network environment using wired media such as coaxial or optical cables is evolving into a wireless one using wireless signals in various frequency bands.
In line with the transition from wired to wireless technology, a computing device that contains a wireless interface module, enables mobility, and perform specific functions by processing various information ("a wireless network device") is being developed and wireless technologies that enable effective communication between wireless devices on a wireless network are emerging.
There are two major architectures of wireless networks: infrastructure and ad-hoc networks.
The infrastructure network contains an access point (AP) 110 as shown in FIG. 1 whereas the ad-hoc network does not require an AP for communication as shown in FIG. 2.
In an infrastructure mode, the AP 110 not only has connectivity to the wired network but also provides communication among wireless network devices within a wireless network. Thus, all data traffic in the infrastructure network is relayed through the AP 110.
In an ad-hoc mode, wireless network devices within a single wireless network can directly communicate with one another without using an AP.
Such ad-hoc mode wireless networks can be further classified into two types.
In one type of network, which is called a "coordinator-based wireless network", a randomly selected wireless device acts as a coordinator that allocates channel time to other wireless devices within the same wireless network for data transmission, and then the other wireless devices are allowed to transmit data only at the allocated time.
As compared to the coordinator-based wireless network, the other type of network allows all network devices to transmit data at any time desired without using a coordinator.
The coordinator-based wireless network is a single independent coordinator-centered network. When there are multiple coordinator-based wireless networks within a certain area, each network has a unique identifier (ID) to distinguish itself from others.
Thus, while wireless devices can transmit data to and receive data from other network devices during channel time allocated by the coordinator on a coordinator-based network where they belong, they are not allowed to communicate with wireless devices belonging to another coordinator-based network.
For example, in a home network system containing two coordinator-based wireless networks, that is, first and second wireless networks 20 and 30, as shown in FIG. 3, it is assumed that the first wireless network 20 is provided in a living room and the second wireless network 30 is provided in a bedroom, respectively.
If a user desires to watch movies stored on a media server 31 in the bedroom using a portable moving picture player 21 in the living room, then the user cannot watch movies since there is no way to communicate between the first and second wireless networks 20 and 30. Thus, in order to watch the movies, the user has to go to the bedroom.
This problem may arise by restriction on range of radio waves, absence of information on another coordinator-based wireless network, and channel time allocation.
In addition, when the user moves the portable moving picture player 21 from the living room to the bedroom to watch the movie, the portable moving picture player 21 attempts to reassociate with the second wireless network 30 after disassociating from the first wireless network 20. When the portable moving picture player 21 attempts to associate with the second wireless network 30, a coordinator of the second wireless network 30 allocates an identifier to the portable moving picture player 21 for discriminating it among other wireless network devices in the second wireless network 30.
Even though the coordinator allocates different identifiers to the wireless network devices belonging to an identical coordinator-based wireless network, there exist wireless network devices having the same identifier allocated previously in a different coordinator-based wireless network.
As described above, when the wireless network devices having the same identifier previously allocated in the different wireless network exist, the wireless network devices must undergo another association process.
Thus, when a wireless network device moves to different wireless networks, it is necessary for the wireless network device to repeatedly perform association processes, consuming unnecessary time and impeding mobility.
Korean Laid-open Patent Application No. 2004-0004726 proposes a method for reducing delay caused by frequent mobile host authentications in a wireless local area network (WLAN) environment using a reduced authentication token. However, the above-cited reference describes only a method for reducing authentication delay based on the IEEE 802.11x standard. However, there has been no teaching nor suggestion based on the IEEE 802.15.x standard.

Wireless network device and communication method using the wireless network device


A liquid infusion system includes a flexible, flat, collapsible bag for storing liquid. An outlet communicates with the bag and a valve is used to control liquid outflow through the outlet tube. A rigid housing encloses the bag with the outlet tube projecting therefrom. A spring biased rigid pivot plate is positioned within the housing. The plate exerts pressure on the bag, tending to urge the bag toward a flat collapsed position and to expel liquids through the outlet when any liquid is present in the bag. Spring members are positioned in wells formed in the housing and the plate. The spring members exert a force against the plate.

1. Field of the Invention
The field of art to which the invention pertains includes the field of liquid infusion systems, and more particularly, to an infusion system having a spring loaded plate for collapsing a bag containing liquid as to aid the flow of liquid without the need for gravity to provide the impetus for the discharge of fluid in the bag.
2. Description of the Prior Art
Apparatus for pressure infusion of blood and parenteral solutions are well known. Pressurized infusion of parenteral solutions and blood is desirable in circumstances where the infusion can be performed independent of gravity. For example, the infusion must be performed at an accelerated rate under emergency conditions or to allow a patient to function while the solution is being administered.
U.S. Pat. No. 4,337,769 utilizes a flexible cellular material to apply pressure to a bag of fluid.
U.S. Pat. No. 3,595,232 utilizes a substantially rectangular container containing a moveable plate which applies pressure to a bag of fluid from the force of an externally located biasing mechanism.
U.S. Pat. No. 4,504,267 utilizes one or more pressure plates which through the use of springs of varying configuration applies pressure to a bag of fluid.
Other known patents include U.S. Pat. Nos. 4,557,728; 4,447,232; 4,781,689; and 3,084,722.
In order to overcome the attendant disadvantages of prior art apparatus which pressure infuse blood and parenteral solutions, the present invention utilizes a simple, yet successful, structure for applying a force to the liquid containing bag. Further, the device may be pre-loaded so that when liquid is to be infused, a simple release mechanism is utilized to commence the flow of liquid.


4,6-O-hydroxyphosphoryl-glucosamine derivatives as shown in the following formula [I] and their pharmaceutically-acceptable salts: ##STR1## wherein R.sub.1 and R.sub.2 represent a hydrogen atom or a hydroxy group; one of R.sub.3 and R.sub.4 represents --OCO(CH.sub.2).sub.n CH.sub.3, --CH.sub.2 (CH.sub.2).sub.n CH.sub.3, or --O--CH.sub.2 (CH.sub.2).sub.n CH.sub.3, and the other represents a hydrogen atom; l is an integer of 4-16; m is an integer of 4-16; and n is an integer of 6-18.

Surface layers of Gram-negative bacteria are composed of a cell membrane, a cell wall peptidoglycan, and an outer membrane. The outer membrane contains lipopolysaccharides (hereinafter abbreviated LPS). LPS is a main ingredient of endotoxin which induces endotoxin shock, and consists of an acidic protein component, a high-molecular weight polysaccharide component, and a phospholipid component.
LPS induces various morbid conditions such as pyrogenesis, bleeding, arthritis, and encephalomyelitis. LPS is also known to exhibit a host protection effect on immune-activating mechanisms such as macrophage-activation, B-cell blastogenesis activity, and cell-mediated immunity-activation, as well as antitumour effects such as IFN(interferon) induction and TNF(tumour necrosis factor) induction.
The main component of LPS which exhibits these activities among said three components is the phospholipid component, which is called lipid A. Lipid A comprises a fatty acid residue and phosphoric acid, both of which are combined with a disaccharide amine, and has the following formula [Japanese Bacteriology Journal 40(1), 57(1985) and Proc. Natl. Acad. Sci. U.S.A. 80, 4624(1983)]: ##STR2##
A recent study has revealed that either the non-reducing subunit or the reducing subunit alone as shown above can exhibit the lipid A-like activity, and various analogues have been synthesized based on this finding. Examples of such analogues are disclosed in European Patent Application Disclosure No. 224260, Japanese Patent Application Disclosure No. 62888/90, and Japanese Patent Application Disclosure No. 25494/90, etc.
As described above, extensive studies have been conducted in order to obtain lipid A analogues, specifically by modifying them with various substituents and by changing introduced substituent sites. However, no lipid A analogue has been developed which is pharmaceutically applicable, mainly because the same substituent exhibits different activities depending on its introduced site, thus making the study of pharmaceutical applications of the lipid A-like analogues difficult. Therefore, lipid A analogues of higher activity and lower toxicity are expected to be developed.


The present disclosure provides a system for providing a security and method of providing an enhanced security booting environment. The system and method includes a basic input/output system (BIOS) stored in memory. The system and method also includes a counter embedded in the memory configured to monitor the number of times each block of the memory has been written. This information could be used with existing error detection mechanisms to improve the ability to detect unintended write operations.

Conventional operating systems (OS) typically include at least two modes of operation: a "user" mode of operation and a "kernel" mode of operation.
Operation in "user" mode is generally limited in the scope of their execution permissions. In other words, operations in user mode typically cannot access protected mode hardware, such as the memory management registers of the processor, without causing an exception. This exception is then caught or handled by another piece of code that has higher permission and the ability to evaluate the user code request and accept or reject it.
"Kernel" mode programs, on the other hand, are assumed to be trusted software. Such programs can execute any instruction and reference any memory addresses.
Accordingly, all user mode software must request use of the kernel by means of a system call in order to perform privileged instructions, such as process creation or input/output operations.
Basic input/output system (BIOS) or boot code is a piece of code that is executed when the processor first comes out of reset. The BIOS initializes hardware and prepares for the launch of the operating system (OS). In other words, the BIOS ensures that all other chips, hard drives, ports, central processing units (CPUs) and any other related system hardware function together. If the BIOS is breached, corrupted or otherwise compromised, then potentially the entire system is compromised.
In an effort to make computing platforms more secure, organizations generally implement levels of trust or "trust zones" in the hardware architecture of computing systems. Each zone typically has a set of execution privileges similar to conventional two-ring operating system execution level. Such systems, however, fail to provide security measures related to the BIOS.
There is therefore a need for security measures to validate, protect and otherwise monitor BIOS or boot code.


Safety of products should be the most important aspect in any product available to the consumer. The following product of making an Easter Egg Paste to be placed on an eggshell to eliminate dye intrusion has been improved by reducing the need for edible salts in the formulation, and eliminating the need for emulsifiers such as soy lecithin and replacing them with more edible safe ingredients.

Coloring eggs with multiple colors is challenging. One could put a sticker on an egg, dye that egg, remove the sticker and dye the egg in a second color and thus get a two color egg. The only problem was the original color that was utilized would now be changed.
Another approach involved the use of a wax crayon or melted wax, allowing a user to write on an egg and locally prevent dye from coloring the eggshell. This is a very inefficient approach, making it utterly impossible to achieve acceptable results.
Also, there are several approaches that utilize sugar as an adhesive, while decreasing the actual solubility of the sugar, which may have some positive results. For example, a method of producing an adhesive composition is disclosed in U.S. Pat. No. 6,613,378 to Erhan et al.
There may be products on the market that use wax or a product that is not consumer edible and thus not safe for children. Utilizing wax is difficult and not particularly safe for children to use. Vaseline or other petroleum type products might have some effectiveness, but lack the safety needed for use by children or adults for that matter.
This background section is intended to introduce the reader to various aspects of typical technology that may be related to various aspects or embodiments of the present invention, which are described and/or claimed below. This discussion is believed to be useful in providing the reader with background information to facilitate a better understanding of the various aspects and embodiments of the present invention. Accordingly, it should be understood that these statements are to be read in light of, and not as admissions of, the prior art.

This patent is subject to a terminal disclaimer.

Formulation to stop the adherence of a dye to an eggshell, improvement


Disk drives, methods, and computer program products are provided for controlling seeking of a transducer that is adjacent to a rotatable data storage disk in a disk drive. The disk drive includes a secondary actuator for positioning the transducer over a second range of movement, and a primary actuator for positioning the secondary actuator over a first range of movement that is larger than the second range of movement. The secondary actuator is controlled to move the transducer toward a target track on the disk while seeking. The primary actuator is controlled to move the secondary actuator toward the target track while simultaneously controlling the secondary actuator to maintain the transducer on the target track.

Computer disk drives store information on disks or platters. Typically, the information is stored on each disk in concentric tracks. The data tracks are usually divided into sectors. Information is written to and read from a storage surface(s) of a disk by a transducer. The transducer may include a read element separate from a write element, or the read and write elements may be integrated into a single read/write element. The transducer is mounted on an actuator arm capable of moving the transducer radially over the disk. Accordingly, the movement of the actuator arm allows the transducer to access different data tracks. The disk is rotated by a spindle motor at a high speed, allowing the transducer to access different sectors within each track on the disk.
The actuator arm is coupled to a motor or coarse actuator, such as a voice coil motor (VCM), to move the actuator arm such that the transducer moves radially over the disk. Operation of the coarse actuator is controlled by a servo control system. The servo control system generally performs two distinct functions: seek control and track following. The seek control function includes controllably moving the actuator arm such that the transducer is moved from an initial position to a target track position. In general, the seek function is initiated when a host computer associated with the computer disk drive issues a command to read data from or write data to a target track on the disk.
As the transducer approaches the target track, the servo control system initiates a settle mode to bring the transducer to rest over the target track within a selected settle threshold, such as a percentage of the track width from track center. Thereafter, the servo control system enters the track following mode wherein the transducer is maintained at a desired position with respect to the target track (e.g., over a centerline of the track) until desired data transfers are complete and another seek is performed.
The ability to precisely position a transducer with respect to a track being followed has become increasingly important, as data and track densities in disk drives have increased. In particular, the space between adjacent tracks has become increasingly small, and the tracks themselves have become increasingly narrow. In order to increase the precision with which a transducer may be positioned with respect to a track during track following, an articulated actuator arm may be used. In general, the angle of the distal portion, or second stage, of the actuator arm with respect to the main portion, or first stage, of the actuator arm is controlled by a microactuator. By operating the microactuator to introduce small changes in the position of the transducer with respect to a track being followed, the accuracy of track following operations may be increased. However, because of the relatively small range of motion provided by microactuators, their range of motion is easily saturated.
As will be appreciated, a disk drive is primarily utilized to transfer data between the tracks of the disks and the host computer. Such data transfer operations usually do not occur during a seek, but rather take place when the drive is in track following mode. Hence, to maximize disk drive data transfer rate capabilities, disk drives may attempt to obtain minimum average seek times.

Multi-stage actuator disk drives, methods, and computer program products for seeking and then maintaining a transducer on track


A semiconductor device includes an insulation film 6 formed on a silicon substrate 1, a buried metal interconnect 8 formed in the insulation film 6, and a barrier metal film 7 formed between the insulation film 6 and the metal interconnect 8. The barrier metal film 7 is a metal compound film. The metal compound film is characterized by including at least one of elements forming the insulation film.

In recent years, as the feature size of semiconductor integrated circuit devices (which will be hereinafter referred to as "semiconductor devices") becomes smaller, a combination of a copper interconnect and an insulation film having a low dielectric constant, i.e., a so-called low-k film has been adopted as a multi-layer interconnect of a semiconductor device. With use of such a multi-layer interconnect, RC delay and power consumption can be reduced. Furthermore, to increase the degree of integration, function and operation speed of a semiconductor device, use of a low-k film having an even lower dielectric constant than that of those presently used is examined.
A copper interconnect is usually formed using a damascene technique. Damascene techniques include a single damascene technique in which an interconnect and a via plug are alternately formed and a dual damascene technique in which an interconnect and a via plug are simultaneously formed.
Hereinafter, a method for forming a multi-layer interconnect by a damascene technique will be described with reference to FIGS. 11(a) and 11(b).
As shown in FIG. 11(a), a first insulation film 102 is formed on a silicon substrate 101 and then a first copper interconnect 104 which is a copper interconnect of a lower layer including a first barrier metal film 103 is formed in the first insulation film 102. On the silicon substrate 101, a transistor and the like (not shown) are formed. Subsequently, a dielectric barrier film 105 for preventing diffusion of copper and a second insulation film 106 are formed in this order over the first insulation film 102 and the first copper interconnect 104. Thus, an insulation layer including the diffusion film 105 and the second insulation film 106 is obtained.
Next, a via hole 106a is formed in the dielectric barrier film 105 and the second insulation film 106 and an interconnect trench 106b is formed in the second insulation film 106. Thus, a recess portion 106c including the via hole 106a and the interconnect trench 106b is obtained. The via hole 106a and the interconnect trench 106b are formed by process steps of forming a dual damascene interconnect trench (i.e., the recess portion 106c including the via hold 106a and the interconnect trench 106b) using known lithography, etching, ashing and cleaning. In general, a method in which after formation of the via hole 106a, the interconnect trench (trench) 106 is formed has widely used (see, for example, Patent Reference 1).
Next, a second barrier metal 107 is formed so as to cover surfaces of the recess portion 106c using physical vapor deposition (PVD) or like film formation method.
Next, on the second barrier metal film 107, a copper seed layer is formed by physical vapor deposition and then a copper film is formed by copper electroplating using the copper seed layer as a seed so as to fill the recess portion 106c and cover an entire surface of the second insulation film 106. Subsequently, parts of the copper film and the second barrier metal film 107 located on the second insulation film, except for parts thereof located inside the recess portion 106c, are removed by chemical mechanical polishing (CMP) to form a second interconnect 108 including a via plug. Note that the second copper interconnect 108 may be an interconnect, a via plug, or a combination of an interconnect and a via plug. A multi-layer interconnect can be formed by repetition of a series of the process steps described above.
Materials used for the second insulation film 106 and the second barrier metal film 107 will be described with reference to FIG. 11(b).
As the dielectric barrier film 105, a silicon nitride film, a silicon nitride carbide film, a silicon carbide oxide film or the like is used. The copper dielectric barrier film 105 has the function of preventing diffusion of copper forming the first interconnect 104 which is a lower layer into the second insulation film 106.
As the second insulation film 106, a silicon oxide film, a fluorine-doped silicon oxide film, a silicon oxide carbide film, or an insulation film formed of an organic film is used. That is, the second insulation film 106 may be a film selected from the group consisting of the films shown in FIG. 11(b) (note that in FIG. 11(b), the case where the second barrier metal film 107 is a metal nitride film is shown). Each of the films may be a film formed by chemical vapor deposition or a SOD (spin on dielectric) film formed by spin coating.
In general, copper is easily diffused in an insulation film such as silicon oxide film by heat or an electric field. This tends to be a cause of deterioration of transistor characteristics. Moreover, copper has poor adhesion with an insulation film. Therefore, in forming a copper interconnect, a method in which a barrier metal film of a tantalum film or a tantalum nitride film is formed between copper and an insulation film to prevent diffusion of copper into the insulation film and also to improve adhesion between the insulation film and copper has been proposed (see, for example, Patent Reference 2). A tantalum film or a tantalum nitride film is used as a single layer or a lamination layer structure.
However, for example, in the above-described example, when a refractory metal such as tantalum is used as the second barrier metal film 107, adhesion between the second insulation film 106 in which the recess portion 106c is formed and the refractory metal film is poor. To cope with the problem of such poor adhesion, for example, if a tantalum film is used as the second barrier metal film 107, a tantalum nitride film is formed between the second barrier metal film 107 made of a tantalum film and the second insulation film 106 to improve poor adhesion. But, in this manner, sufficient adhesion is still not obtained.
Moreover, when a tantalum film is used as the second barrier metal film 107, the tantalum film is oxidized in forming copper by electroplating, so that a high resistance tantalum oxide film is formed. For this reason, increase in interconnect resistance can not be avoided.
Moreover, when a tantalum nitride film is used as the second barrier metal film 107, the tantalum nitride film is not oxidized. However, a tantalum film has a high resistance and adhesion with copper is poor.
Furthermore, when a titanium film or a titanium nitride film is used as the second barrier metal film 107, the same problems arise as when a tantalum film or a tantalum nitride film is used.
In view of the above-described problems, a metal such as ruthenium and iridium which itself or whose oxide has a low resistance is used as the second barrier metal film 107 to achieve reduction in resistance of the second barrier metal film 107 (see, for example, Patent Reference 3 and Patent Reference 4), and this technique has attracted interest. In general, such metals are formed by atomic layer deposition or chemical vapor deposition.
(Patent Reference 1) Japanese Laid-Open Publication No. 10-223755
(Patent Reference 2) Japanese Laid-Open Publication No. 2002-43419
(Patent Reference 3) Japanese Patent Publication No. 3409831
(Patent Reference 4) Japanese Laid-Open Publication No. 2002-75994

Semiconductor device including a barrier metal film


The present invention relates to an improvement muffler that includes an improved inlet configuration having first and second sequential chambers with a perforated central pipe passing longitudinally through a central region of both chambers for directing the exhaust gases into the third chamber in which the deflection element is deployed. Additionally, the partition separating the first and second chamber has a hole that enables some of the gas to pass from the first chamber into the second chamber not through the central pipe.

The present invention relates to sound-attenuating mufflers for internal combustion engines and, more particularly, to sound-attenuating mufflers generating reduced back pressure.
Numerous muffler constructions have been proposed for the attenuation of the sound component of an exhaust gas stream from an internal combustion engine. The present invention is an improvement to the low back-pressure sound-attenuating mufflers of U.S. Pat. Nos. 6,286,623 and 6,776,257 to the present inventor and incorporated herein by reference.
The low back-pressure sound-attenuating mufflers of U.S. Pat. Nos. 6,286,623 and 6,776,257 are well suited for sports cars.
There is therefore a need for a low back-pressure sound-attenuating muffler having a lower decibel output than the previous mufflers so as to be usable on regular passenger vehicles.

Sound-attenuating muffler having reduced back pressure


A method is disclosed for preparing and recovering metal nitrides from their ferrometal alloys and nickel metal alloys. Exemplary steps of the process involve niobium nitride prepared from ferroniobium alloys (FeNb) which are first hydrided to provide a friable, comminutable product which is then nitrided under conditions which form distinct phases of iron nitride and niobium nitride respectively.

Exemplary of the preparation of the Group IV, V and VI metal nitrides is the preparation of niobium nitride. The preparation of niobium nitride from ferroniobium (FeNb) has, in the past, been done in a variety of circuitous ways. The high cost of recovering niobium nitride by the use of several of the known processes has deterred their commercial adoption.
Exemplary of the known methods include the production of niobium oxide (Nb.sub.2 O.sub.5) from FeNb in a multiple step process. The niobium oxide can then be metallothermically or carbothermically reduced to yield metal suitable for further purification by melting. The metal can then be nitrided directly or the Nb.sub.2 O.sub.5 can be nitrided with ammonia.
The typical extraction processes include chlorinating FeNb directly to produce ferric chloride (FeCl.sub.3) and niobium pentachloride (NbCl.sub.5) ) by passing chlorine through a bed of particulate FeNb held at a temperature of from about 500.degree. C. to 1000.degree. C.
The chlorination reaction can be characterized as follows: EQU FeNb+4Cl.sub.2 .fwdarw.FeCl.sub.3 +NbCl.sub.5 +heat
This reaction is exothermic and once started produces considerable heat and must, therefore, be carefully controlled. The FeCl.sub.3 and NbCl.sub.5 produced must be subsequently separated and this is accomplished by passing the mixed chlorides in the vapor state through a heated bed of sodium chloride (NaCl) where the FeCl.sub.3 forms a eutectic composition with the NaCl and is thereby removed from the vapor process stream. The NbCl.sub.5 can then be subsequently condensed by cooling.
This chlorination step utilizes toxic chlorine gas at elevated temperatures and pressures potentially raising corrosion and, therefore, safety problems. Special equipment is necessary for handling the highly pressurized, corrosive liquid chlorine and it must be carefully vaporized, metered and fed into the reactor. Likewise, the most suitable material for reactor construction is graphite. Graphite is a brittle material which can fracture and fail abruptly after a short time in use in this environment. Further, the vaporized chlorine is normally used in excess to ensure complete reaction with the FeNb and the excess must subsequently be neutralized creating an expensive, undesirable by-product.
The separated condensed NbCl.sub.5 can then be hydrolyzed by its addition to water and then the bath is neutralized and the insoluble product can be dried and then calcined, or calcined directly in a heated kiln in the presence of oxygen to produce Nb.sub.2 O.sub.5. The hydrolysis and neutralization steps can produce undesirable by-products and the drying and calcining steps are both energy intensive and expensive.
The Nb.sub.2 O.sub.5 obtained as described can then be metallothermically reduced with aluminum powder in a batch reaction to form Nb metal according to the following equation: EQU 3Nb.sub.2 O.sub.5 +10Al.fwdarw.6Nb+5Al.sub.2 O.sub.3 +heat
This reaction is very exothermic attaining temperatures in excess of the melting point of the products which are then separated by gravity while in the molten state. While expensive, metallothermic reduction is effective with good yields.
The other methods for Nb extraction from FeNb involve caustic or carbonate fusions, which when leached or washed, give niobium oxide which is fairly pure and may be purified further by chlorination as previously described or other means presently known to the art. Ultimately, the oxide must be metallothermically reduced as previously described, or carbothermically reduced to Nb metal.
The process of reducing Nb.sub.2 O.sub.5 carbothermically is difficult to do on a production basis since doing so requires a large thermal input, vacuum vessels, and a careful balance of carbon to oxygen so that the resulting metal is not contaminated with either carbon or oxygen. If the carbon to oxygen ratio is maintained at nearly stoichiometric amounts, then the reaction proceeds rapidly until only a few percent of either remains unreacted. The reaction then proceeds slowly and it is quite difficult for it to reach completion. For this reason, carbothermic reduction is not currently used commercially.
Another method for extracting Nb from FeNb could theoretically be the direct electron beam melting and purification of FeNb by preferential vaporization of the Fe. This becomes very expensive in practice even though the melting point of FeNb is relatively low, a great amount of electrical power is needed to superheat and vaporize the relatively large amount of iron present. Though possible, it is not economically feasible.
Numerous synthesis techniques for niobium nitride preparation are given in the monograph "Hartstoffe", by Kieffer and Benesovsky (Springer-Verlag, Vienna, 1963), p. 317. Among the techniques reviewed therein, the following are noteworthy here.
First, partial hydrogen reduction of Nb.sub.2 O.sub.5 to Nb.sub.2 O.sub.3 can be employed followed by nitriding of the Nb.sub.2 O.sub.3 in the presence of carbon. The potential of such a process is limited by the availability of high quality Nb.sub.2 O.sub.5, and the previously described process difficulties in preparing Nb.sub.2 O.sub.5 commercially suitable for such use.
Next, direct combination of pure niobium metal with nitrogen or ammonia can be employed. Since pure niobium metal is the penultimate product of niobium extractive metallurgy, such a route necessarily represents the most expensive possible for the subsequent production of the nitride.
Further, nitridation of Nb.sub.2 O.sub.5 in the presence of carbon can be employed, as reported by Krishnamurthy, et al R&HM, March 1984, pages 41-45. This process requires difficult pyrovacuum treatment to remove both carbon and oxygen. Furthermore, since that process is intended to ultimately produce niobium metal, the nitride it produces has large amounts of oxygen and carbon.
Still further, it is possible to produce niobium nitride by the direct reaction of Nb.sub.2 O.sub.5 with ammonia. U.S. Bureau of Mines Reports of Investigation 8075 (1975) and 8103 (1976) describes this work, which starts with costly Nb.sub.2 O.sub.5 and ammonia and can also be used to produce niobium metal.

Method for the preparation of niobium nitride


A drill bit for drilling a borehole having a bit body with an axis of rotation, a leading face, and a plurality of blades upstanding from the leading face. At least one of the blades terminates in a gauge pad having a gauge surface arranged, in use, to face a wall of the borehole. The gauge surface being devoid of cutting elements and terminating at an end remote from the blade at a junction with a gauge pad end wall. The gauge pad carries a cutter having a face and a cutting edge located radially inward of the gauge surface, and the junction of the gauge surface and the gauge pad end wall crosses, radially, between the face of the cutter and the wall of the borehole. The gauge surface may be a substantially continuous surface, and may have at least one additional cutter located angularly between two adjacent blades of the drill bit.

1. Field of the Invention
This invention relates to earth boring drill bits, and in particular to a fixed cutter drill bit having cutting elements positioned so as to facilitate directional drilling.
2. Description of the Related Art
Until quite recently, drill bit designers worked primarily on designing drill bits which would drill straight holes through the earth. More recently, designers have been working on bit designs which, when used in conjunction with suitable downhole equipment, can be steered to permit directional drilling. In directional drilling, it is important to ensure that the drill bit does not wander from the desired path. In addition, the bits must be easy to steer and be able to hold a horizontal drilling trajectory.
There are two common ways to steer a drill bit. One method is to use a downhole motor to rotate the drill bit, the motor and drill bit being mounted upon a drill string including an angled bend. In such an arrangement, the direction of drilling is dependent upon the angular position of the drill string. In use, the drill string is rotated until the drill bit is pointing in the desired direction. The drill string is then held against further angular movement while drilling in the desired direction takes place. This steering technique is sometimes known as xe2x80x9cpointing the bitxe2x80x9d.
An alternative steering technique is known as xe2x80x9cpush the bitxe2x80x9d. In this technique, the drill bit is rotated continuously. Associated with the drill bit is a unit designed to permit the application of a side load to the drill bit to cause the direction of drilling to deviate from the straight path it would otherwise follow. U.S. Pat. Nos. 5,265,682; 5,553,679; 5,582,259; 5,603,385; 5,685,379; 5,706,905; 5,778,992; 5,803,185 all incorporated herein by reference for all they disclose, describe a unit suitable for use in a xe2x80x9cpush the bitxe2x80x9d type steerable drilling system.
A known drill bit suitable for use in a steerable drilling system of the xe2x80x9cpush the bitxe2x80x9d type has a leading face from which a plurality of blades upstand, each blade carrying a plurality of cutting elements. Each blade terminates in a gauge pad. In a typical drill bit, the gauge pads are not provided with cutting elements, but may be provided with inserts designed to improve the wear resistance of the gauge pads. It has been found, however, to be advantageous in a xe2x80x9cpush the bitxe2x80x9d type system to provide the gauge pads with cutting elements. One disadvantage, however, of applying cutting elements to the gauge pads is that there is a tendency for a wellbore formed using the drill bit to drop. This is due to the gravitational effects experienced by the drill bit, the effect being greatest where a horizontal bore is to be drilled, the gravitational effects applying a side loading to the drill bit causing the cutters of the gauge pads located at the lower side of the bit at any given time to become active in drilling the borehole.
The present invention provides a drill bit particularly suitable for use in a steerable drilling system of the xe2x80x9cpush the bitxe2x80x9d type.
According to the present invention there is provided a drill bit for drilling a borehole, the drill bit comprising a bit body having an axis of rotation, a leading face, a plurality of blades upstanding from the leading face, at least one of the blades terminating in a gauge pad having a gauge surface arranged, in use, to face a wall of the borehole, the gauge surface being devoid of cutting elements, the gauge surface terminating at an end thereof remote from the blade at a junction with a gauge pad end wall, wherein the gauge pad carries a single cutter having a face and a cutting edge located radially inward of the gauge surface, and wherein the junction of the gauge surface and the gauge pad end wall crosses, radially, between the face of the cutter and the wall of the borehole.
Preferably each blade terminates in a similar gauge pad, each gauge pad carrying a single cutter. Each cutter conveniently comprises a table of a superhard material bonded to a substrate. The superhard material preferably comprises diamond.
The cutting edge is preferably spaced radially inward of the gauge surface by a distance greater than about 0.15 mm, and preferably between about 0.2 mm and 0.5 mm.
A line drawn between the cutting edge and the junction conveniently makes an angle with the axis of the bit of less than about 0.1xc2x0.
According to another aspect of the invention there is provided a drill bit for drilling a borehole, the drill bit comprising a bit body having an axis of rotation, a leading face, a plurality of blades upstanding from the leading face, at least one of the blades terminating in a gauge pad having a gauge surface arranged, in use, to face a wall of the borehole, the gauge surface being devoid of cutting elements, the gauge surface terminating at an end thereof remote from the blade at a junction with a gauge pad end wall, wherein the gauge pad carries a single cutter having a face and a cutting edge located radially inward of the gauge surface, the radial spacing of the cutting edge from the gauge surface being greater than about 0.15 mm.
According to yet another aspect of the invention there is provided a drill bit for drilling a borehole, the drill bit comprising a bit body having an axis of rotation, a leading face, a plurality of blades upstanding from the leading face, at least one of the blades terminating in a gauge pad having a gauge surface arranged, in use, to face a wall of the borehole, the gauge surface being devoid of cutting elements, the gauge surface terminating at an end thereof remote from the blade at a junction with a gauge pad end wall, wherein the gauge pad carries a single cutter having a face and a cutting edge located radially inward of the gauge surface, and wherein a notional line between the junction and the cutting edge makes an angle with the axis of rotation of less than about 0.1xc2x0.
According to another aspect of the invention there is provided a drill bit for drilling a borehole, the drill bit comprising a bit body having an axis of rotation, a leading face, a plurality of blades upstanding from the leading face, at least one of the blades terminating in a gauge pad having a gauge surface arranged, in use, to face a wall of the borehole, the gauge surface being devoid of cutting elements, the gauge surface terminating at an end thereof remote from the blade at a junction with a gauge pad end wall, wherein the gauge pad carries a single cutter having a face and a cutting edge located radially inward of the gauge surface, and wherein an axial position of the junction of the gauge surface and the gauge pad end wall lies between an axial position of an edge of the cutter face closest to the blade and an axial position of an edge thereof furthest from the blade.
According to a further aspect of the invention there is provided a steerable drilling system for use in the drilling of a borehole comprising a bottom hole assembly (BHA) adapted to permit control over the direction of drilling of a drill bit, the drill bit comprising a bit body having a plurality of blades, at least one of the blades terminating in a gauge pad having a gauge surface devoid of cutting elements, the gauge pad having, at an end thereof remote from the blade, a gauge pad end wall, the gauge pad carrying a single cutter located inward of the gauge surface and such that an axial position of a junction between the gauge surface and the gauge pad end wall lies between an axial position of an edge of the cutter closest to the blade and an axial position of an edge of the cutter furthest from the blade.
The bottom hole assembly (BHA) may be of the xe2x80x9cpush the bitxe2x80x9d type including a bias unit arranged to apply a side loading to the bit. Alternatively, the bottom hole assembly may be of the xe2x80x9cpoint the bitxe2x80x9d type, including a downhole motor for rotating the drilling bit, and an angled member arranged to permit the bit to be supported in a desired orientation relative to an axis of the borehole.
It is envisaged that the drill bit may be used in a drilling system which is, in effect, a combination of the xe2x80x9cpush the bitxe2x80x9d and xe2x80x9cpoint the bitxe2x80x9d types, the system including, for example, a bias unit arranged to apply a side loading to a bent unit which carries a motor, the motor carrying the drill bit. In such an arrangement, when the system is to be used to drill a curve, the drill string is held against rotation with the bent unit holding the drill bit in the desired orientation while the motor drives the drill bit, and the bias unit is operated to apply a side loading to the bent unit and the drill bit.
Where a side loading is applied to a bit, either by a bias unit to which the bit is connected or by a bias arrangement forming part of the bit, it is thought to be advantageous for the xe2x80x9csingle cutterxe2x80x9d referred to hereinbefore to be located on a side part of the bit directly opposite the bias unit pad causing the application of the side loading at any given time. Although this is possible where the number of xe2x80x9csingle cuttersxe2x80x9d is equal to or a multiple of the number of bias unit pads, it requires the drill bit to be correctly angularly orientated relative to the bias unit, where the bias unit is a separate component. Obviously, if the number of xe2x80x9csingle cuttersxe2x80x9d is not equal to or a multiple of the number of bias unit pads, then such positioning cannot be achieved with the arrangements described hereinbefore.
Accordingly, in each of the arrangements hereinbefore, the gauge pads may be integral with one another and form a gauge surface extending around the bit body, additional similarly located cutters being carried by the bit body between the angular positions of the blades.
By providing additional similarly located cutters, the requirement for the bias unit pad to be located opposite one of the blades is removed. The bit therefore can be used with a wide range of bias units and there is no need to accurately angularly align the bit with the bias unit.
According to another aspect of the invention there is provided a drill bit for drilling a borehole, the drill bit comprising a bit body having an axis of rotation, a leading face, a plurality of blades upstanding from the leading face, and a gauge surface extending around the bit body and arranged, in use, to face a wall of the borehole, the gauge surface being devoid of cutting elements, the gauge surface terminating at an edge thereof remote from the blades at a junction with a gauge pad end wall, wherein the bit body carries a plurality of cutters each having a face and a cutting edge located radially inward of the gauge surface, and wherein the junction of the gauge surface and the gauge pad end wall crosses, radially, between the face of each cutter and the wall of the borehole.

Cutting structure for earth boring drill bits


A membrane filtration system with reverse osmosis (RO) or nanofiltration (NF) elements is adapted to provide high recovery from difficult wastewater. The system has a plurality of stages. The system is configured to provide concentrate staging. The last stage also has concentrate recirculation. The valves and pumps of the system are arranged such that the order of flow and a recirculation pump may be switched between the first stage and the last stage at some times.

Reverse osmosis (RO) and nanofiltration (NF) membranes are typically used in the form of elements, also called modules, such as spiral wound elements, hollow fiber elements or tubular elements. A number of elements, typically between 1 and 8, are mounted in series in a pressure vessel, alternatively called a housing, with a feed inlet, concentrate outlet, and permeate outlet. Multiple pressure vessels may be connected together in parallel to form a bank, alternatively called a stage, in a filtration system. The stages of a filtration system are collectively referred to as a membrane block.
A filtration system may have multiple stages connected together in various configurations. In concentrate staging, alternatively called a multi-stage array, feed water is first pumped into a first stage of elements. Concentrate from each upstream stage is fed to each downstream stage. The concentrate port of the last stage is fitted with a concentrate valve. The flow and pressure through the membrane block are controlled by the feed pump and concentrate valve. Permeate flows from each stage to a common permeate header. The concentrate staging increases permeate recovery. Filtration systems with high recovery rates, for example 80% or more, typically have at least two stages.

Membrane filtration system with concentrate staging and concentrate recirculation, switchable stages, or both


Shoulder pads for a player playing a contact sport, such as hockey, lacrosse or football, are provided. The shoulder pads comprise a front member, a back member, left and right shoulder arches, left and right shoulder protectors, and an adjustment system allowing the player to adjust a fit of the shoulder pads. The adjustment system may allow the player to adjust various components of the shoulder pads, including the front member, the back member, and the left and right shoulder protectors, in various directions.

Shoulder pads are worn by players of contact sports, such as hockey, lacrosse and football, for upper body protection. Typically, shoulder pads comprise front and back members for respectively protecting front and back regions of a player's thorax and left and right shoulder protectors for respectively protecting the player's left and right shoulders.
A fit of a player's shoulder pads can be important to properly protect the player and facilitate movement of the player. However, the shoulders pads may be limited in terms of how well they can fit the player and this may adversely affect protection and/or movement of the player. For example, the shoulder pads' front and back members may be sewn or otherwise permanently joined such that their shoulder arches arching over the player's shoulders and interconnecting the front and back members are fixed. This may cause the shoulder pads to "sit" or lay poorly on the player. For instance, the shoulder pads may "float" on top of the player, i.e., they may not lay down on the player's shoulders between the player's chest and back. Also, the shoulder arches may be padded and their fixed nature may cause their padding to bunch up or not flex properly.
For these and other reasons, there is a need for improvements in shoulder pads, including improvements directed to improving a fit of a player's shoulder pads.