A pneumatically actuated valve assembly for use as intake and/or exhaust valves on two- or four-stroke internal combustion engines. The assembly includes a valve (100), valve housing (200), and compressed gas distribution and timing mechanisms (FIGS. 5–8). The valve (100) is comprised of a short light weight hollow cylindrical body with a capped lower end and an opened upper end. The valve is further defined by a plurality of ports (104) adjacent to the lower end and a collar (198) encircling the body adjacent the upper end. The valve housing (200) is hollow and tubular having a larger diameter upper section and a smaller diameter lower section in which the valve (100) slides up to close and down to open. The housing (200) further includes hollow channels which direct compressed gas, managed by the distribution and timing mechanism, alternately towards the areas above and below the valve collar at regular intervals to open and close the valve, respectively.

Generally, four stroke internal combustion engines utilized valves to allow exhaust to leave the working (combustion) chamber of the engine cylinder after the combustion stroke, as well as to allow a new air charge to enter the cylinder to begin the cycle anew during the intake stroke. Two stroke internal combustion engines on the other hand may utilize valves for both intake and exhaust or a valve for intake and a port for exhaust. Such valves have traditionally been invariably actuated by a cam affixed to a shaft (the cam shaft), or alternatively by an electromagnetic or hydraulic device.
It would be greatly advantageous to provide another more efficient way to actuate valve reciprocation on internal combustion engines. Valves which rely on a cam shaft usually require heavy springs and a large number of other moving parts that absorb a large amount of energy and create a great deal of friction. Additionally, such systems are relatively expensive to operate.
U.S. Pat. No. 6,349,691 to Klein (one of the inventors named herein) describes a partial solution in the form of a valve for air intake. The valve is responsive to pressure differential between the manifold and combustion chamber. Specifically, the valve closes in response to the increase in pressure in the cylinder as the piston rises (after passing bottom dead center and approaching the top of the cylinder). Unfortunately, a problem with this intake valve assembly is that inertia and, to a lesser extent friction, retards the valve's speedy closure, thus negatively affecting engine performance.
Therefore, it would be advantageous to provide an externally regulated pressure actuated valve system.
The present inventors have also filed U.S. patent application Ser. No. 10/449,754 on May 30, 2003, which introduces a system of using a spring to accelerate the valve closing, and a means to vary non-cyclically the base force of the spring so that the proper amount of spring force can be used under varying conditions of engine speed and load. While this variable spring force intake valve system is reliable, it still presents a lingering concern. Specifically, when the spring force is adjusted (i.e. during a regime of higher engine speed) the period of time during which the valve is open to allow ventilation is shortened. Thus, an insufficient amount of intake air enters the cylinders, negatively effecting engine performance.
Additionally, the present inventors have filed a U.S. Provisional Patent Application No. 60/444,532 on Jan. 31, 2003, which introduced another more energy efficient intake valve assembly. The provisional patent application disclosed both a unique compressed air actuated intake valve system (either wholly air operated or spring-assisted) and a unique air distribution system using a single air source for actuating the intake valve. The valve is short and lightweight, having collar. The valve sits in a housing atop an engine cylinder and is connected to the air distribution system. Compressed air is either directed over the top of the valve forcing it downward and open or into a hollow chamber within the valve housing where the compressed-air applies pressure under the valve collar, forcing the valve upward and closed. The disclosed air distribution system uses a rotating disk assembly with air outlets to direct airflow as necessary to raise and lower the valve. While the valve assembly disclosed in this provisional patent application is sound, there is a slight disadvantage associated with this air distribution system. Namely, the air distribution system, as disclosed, requires lubrication for the rotating disks and upon heating the presently available lubrications may release unwanted and harmful hydrocarbons into the atmosphere. Additionally, the valve was illustrated for use only as an intake valve, not as either an intake or exhaust valve.
It would be advantageous over the prior art to provide a wholly forced-air actuated valve system, using one or multiple air sources, operable on either a four stroke or a two stroke internal combustion engine, to open and/or close intake and/or exhaust valves. It would also be advantageous to provide a system for efficiently regulating the timing of the valve open/close (reciprocation) cycle relative to the engine speed. It would further be advantageous to provide such a system that does not require the use of lubricants that may release harmful by-products into the environment.

Pneumatically actuated valve for internal combustion engines


Improved techniques for loading class files into virtual computing machines are disclosed. The techniques seek to provide a mechanism that will generally improve the efficiency of virtual machines by selectively loading information into a virtual machine. A new class attribute (“load-attribute”) is defined and implemented for class files. This can be, for example, implemented as a “load-attribute” table that lists the components that have been selected for loading into the virtual machine. In addition, the load-attribute may provide references to the selected components in the class file. Accordingly, various components of the class file can be marked for loading and selectively loaded.

1. The Field of the Invention
The present invention relates generally to object-oriented programming environments. More specifically, the invention relates to improved frameworks for loading class files into virtual computing machines.
2. The Relevant Art
The present invention relates generally to object-based high level programming environments, and more particularly, to virtual machine instruction sets suitable for execution in virtual machines operating in portable, platform independent programming environments.
Recently, the Java™ programming environment has become quite popular. The Java™ programming language is a language that is designed to be portable enough to be executed on a wide range of computers ranging from small devices (e.g., pagers, cell phones and smart cards) up to supercomputers. Computer programs written in the Java programming language (and other languages) may be compiled into Java Bytecode instructions that are suitable for execution by a Java virtual machine implementation.
The Java virtual machine is commonly implemented in software by means of an interpreter for the Java virtual machine instruction set but, in general, may be software, hardware, or both. A particular Java virtual machine implementation and corresponding support libraries together constitute a Java™ runtime environment.
Computer programs in the Java programming language are arranged in one or more classes or interfaces (referred to herein jointly as classes or class files). Such programs are generally platform, i.e., hardware and operating system, independent. As such, these computer programs may be executed, without modification, on any computer that is able to run an implementation of the Java™ runtime environment.
Object-oriented classes written in the Java programming language are compiled to a particular binary format called the "class file format." The class file includes various components associated with a single class. These components can be, for example, methods and/or interfaces associated with the class. In addition, the class file format includes a significant amount of ancillary information that is associated with the class. FIG. 1A illustrates a class file structure. The class file format (as well as the general operation of the Java virtual machine) is described in some detail in The Java Virtual Machine Specification by Tim Lindholm and Frank Yellin (ISBN 0-201-31006-6), which is hereby incorporated herein by reference.
Generally, when a class file is loaded into the virtual machine, the virtual machine essentially makes a copy of the class file for its internal use. The virtual machine's internal copy is sometimes referred to as an "internal class representation." In conventional virtual machines, the internal class representation is typically almost an exact copy of the class file. This is true regardless of whether the loaded information is likely to be used or not. For example, typically, an exact copy of common Java classes (e.g., class PrintWriter) are loaded into the virtual machine. These common classes typically have a large size. For example, the class PrintWriter may take up as much as 40 KiloBytes (40 K) of memory. However, 90% of the common class is often not used during the execution of a computer program. This, of course, results in a grossly inefficient use of memory resources. In some circumstances, particularly in embedded systems with limited memory resources, this inefficient use of memory resources is a significant disadvantage.
In view of the foregoing, improved techniques for loading class files into virtual computing machines are needed.

Loading attribute for partial loading of class files into virtual machines


A system and method for communicating messages includes receiving, from a first client associated with a calling party, a request for connection with a second client. A called party associated with the second client is notified that the request for connection was received, in response to receiving the request for connection. A connection processing instruction may be received from a third client associated with the called party. In accordance with a particular embodiment of the present invention, the request for connection may be processed in accordance with the connection processing instruction.

Voice messaging is widely used in the business community to record messages from people trying to contact others that are not available. This modality enables people to communicate from any POTS or simple IP phone. Instant messaging (IM) allows people to communicate with others while being on a computer or a hand-held device connected to a network. This gives them the benefit of mobility while being able to stay in touch with others.

Method and system for managing communication sessions between a text-based and a voice-based client


Various embodiments of wafer bonding apparatuses and methods are described herein for reducing distortion in a post-bonded wafer pair. More specifically, the present disclosure provides embodiments of wafer bonding apparatuses and methods to reduce post-bond wafer distortion that occurs primarily within the center and/or the edge of the post-bonded wafer pair. In the present disclosure, post-bonded wafer distortion is reduced by correcting for variations in the pre-bond wafer shapes. Variations in pre-bond wafer shape are corrected, or compensated for, by making hardware modifications to the wafer chuck. Such modifications may include, but are not limited to, modifications to the surface height and/or the temperature of the wafer chuck. Although hardware modifications are disclosed herein for reducing post-bond wafer distortion near the center and/or the edge of the post-bonded wafer pair, similar modifications can be made to reduce post-bond wafer distortion within other areas or zones of the post-bonded wafer pair.

The present disclosure relates to the processing of substrates. In particular, it provides an improved chuck design and wafer bonding process that reduces post-bond wafer distortion.
A wafer bonding apparatus (or "wafer bonder") physically joins two wafers (an upper wafer and a lower wafer) together through interfacial adhesion. The lateral misalignment along the bonding interface is referred to as the post-bond distortion error. The post-bond distortion error is a function of the pre-bond wafer shapes and the wafer bonding process (e.g., the tool recipe), and is often used to judge the performance of the wafer bonding apparatus.
There are two main types of wafers used in wafer bonding processes: device/device pair and device/carrier pair. A device wafer is a patterned wafer with nanoscale electrical circuits created on the surface of the wafer. A carrier wafer is typically a blank wafer without any patterns on the surface of the wafer. For a device/device wafer pair, the absolute lateral misalignment between the two wafers anywhere along the bonding interface is critical, and may typically be around 100 nm for state-of-the-art technology. In contrast, the relative lateral misalignment is more important in a device/carrier wafer pair. Since there are no patterns in a carrier wafer, the absolute lateral misalignment between the two bonded wafers is affected by the ability of the lithography tool to pattern the carrier wafer in subsequent processing step(s). This misalignment can be corrected, at least partially, by the lithography tool. Therefore, the relative lateral misalignment for a device/carrier wafer pair is the absolute misalignment minus the correction that can be applied in subsequent processing step(s). Depending on the correction capability of the subsequent step(s), the relative lateral misalignment between a device/carrier wafer pair may be less than 10 nm for state-of-the-art technology. The absolute and relative lateral misalignments will be referred to as "distortion" in the following paragraphs.
FIGS. 1A-1C (Prior Art) illustrate a conventional wafer bonding apparatus 10 and process that may be used to bond two wafers together. The wafer bonding apparatus 10 includes an upper chuck 12 and a lower chuck 14, which hold an upper wafer 16 and lower wafer 18 in place, respectively. In some cases, vacuum pressure may be used to hold the wafers on the chucks. As shown in FIG. 1A, the two wafers are initially separated by a small gap (g). Next, the center of the upper and lower wafers are pushed into contact, sometimes assisted by a mechanical force applied to the center of the upper wafer 16. As shown in FIG. 1B, for example, a striker pin (or bonding pin) 19 may be used to apply a mechanical force to the center of the upper wafer 16, which causes the upper wafer to bow or bend until the center of the upper wafer 16 makes contact with the center of the lower wafer 18. This contact initiates a bonding front that spontaneously propagates radially outward from the center of the upper and lower wafers. As the contact surface area increases, the upper and lower wafers elastically deform in order to close the initial gap (g) between the wafers. The vacuum pressure to the upper chuck 12 is turned off. When the contact surface area is large enough, the vacuum seal between the upper chuck 12 and upper wafer 16 breaks, due to either the deformation of wafers or the predetermined recipe setting. The bonding front continues to propagate outwards until the two wafers are fully bonded. Once the bond is complete, the striker pin 19 retracts and the vacuum pressure to the lower chuck 14 is turned off, as shown in FIG. 1C. The post-bonded wafer pair 16/18 may then be released from the wafer bonding apparatus 10, sent to a metrology tool for distortion characterization and/or continue on to the next processing step.
In some cases, the conventional wafer bonding apparatus 10 and process shown in FIGS. 1A-1C may result in poor post-bonded wafer distortion near the center and/or the edge (e.g., within the outermost 15 mm) of the post-bonded wafer pair 16/18. Specifically, FIG. 1C illustrates an upward bending of the post-bonded wafer pair 16/18 near the edge or outer periphery of the post-bonded wafer pair. The upward bending shown in FIG. 1C is one example of post-bonded wafer distortion (e.g., an outward distortion) that may occur after a conventional wafer bonding process is used to bond two wafers together. Distortion may also occur within other regions (e.g., near the center) of the post-bonded wafer pair when a conventional wafer bonding process is used. Regardless of location, post-bonded wafer distortion causes a lateral shift (or lateral misalignment) between the two wafers in the area of distortion.
The post-bonded wafer distortion shown in FIG. 1C may be due to a number of reasons. First, pre-bonded wafers typically have different specifications near the edge. For example, some wafers may have a tapered edge, or a smaller thickness near the edge or outer periphery (e.g., the outermost 3 mm) of the wafer. This leads to a difference in the mechanical performance of the wafer at/near the edge (compared to the rest of the wafer), which may lead to poor distortion in the post-bonded wafer pair. In addition, pre-bonded wafers may be processed differently in other processing steps (e.g., different patterning arrangements) to improve device yield. The difference in process often results in different pre-bonded wafer shapes near the edge or outer periphery. Variations in pre-bonded wafer shape is another cause of post-bonded wafer distortion. Furthermore, a wafer bonding process can be conceived as a two-phase process—before and after the chuck vacuum seal is broken. Once the vacuum seal is broken between the chuck and the wafer, there are fewer distortion controls from the wafer bonding apparatus, which may result in poor distortion at the edge.
FIG. 2 is a graph illustrating distortion of a post-bonded wafer pair (i.e., post-bond wafer distortion) as a function of radius (r) when a conventional wafer bonding apparatus and process is used to bond two wafers together, as discussed above for example in reference to FIGS. 1A-1C. In the graph shown in FIG. 2, the distortion 20 increases significantly near the edge of the post-bonded wafer pair. In some wafer bonding processes, the distortion 20 near the edge of the post-bonded wafer pair can be up to, e.g., 20 nm worse than the distortion 20 across the rest of the wafer pair. It is estimated that the post-bond distortion error can improve, e.g., by 15% or more, when wafer edge distortion is improved.

Wafer bonding apparatus and methods to reduce post-bond wafer distortion


Embodiments provide WiFi and LTE tailored transceiver radio frequency (RF) filtering techniques and configurations to enable coexistence between WiFi and LTE transceivers operating in close proximity. In particular, embodiments provide filtering techniques to reject emissions from LTE into WiFi, and vice versa. The filtering techniques eliminate the need for additional isolation between LTE and WiFi antennas (approximately 50 dB), which is beyond what is achievable in practice. Embodiments can be tailored according to different use cases of the WiFi and LTE transceivers (e.g., fixed CPE, portable router, smart phone with tethering).

1. Field of the Invention
The present invention relates generally to wireless communications.
2. Background Art
According to the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard, WiFi devices may operate on eleven channels (channels 1 through 11) located in the 2.4-GHz ISM (Industrial, Scientific, Medical) band, which spans from 2400 MHz to 2483.5 MHz. Each WiFi Channel is 22 MHz wide, and consecutive WiFi channels are separated by 5 MHz. Channels 1, 6, and 11 are non-overlapping channels centered at 2412 MHz, 2437 MHz, and 2462 MHz, respectively.
The WiMAX (Worldwide Interoperability for Microwave Access) forum has published three licensed spectrum profiles (2.3 GHz, 2.5 GHz, and 3.5 GHz) for IEEE 802.16e WiMAX devices. The 2.5 GHz spectrum profile corresponds to the Federal Communication Commission (FCC) Broadband Radio Service (BRS) band (2496 MHz to 2690 MHz). The FCC BRS band is divided in 5.5-MHz or 11-MHz channels with corresponding 5-MHz and 10-MHz WiMAX system bandwidths.
Accordingly, in certain scenarios, the guard band between WiFi and WiMAX operating bands may be less than 20-MHZ (e.g., in the case of WiFi operating on channel 11 and WiMAX using an 10-MHz channel centered at 2496 MHz, only 18 MHz separate the operating channels). Thus, when a WiFi transceiver and a WiMAX transceiver operate in close proximity to each other, the two transceivers may interfere with one another in the absence of synchronization. Accordingly, there is a need to ensure coexistence between WiFi transceivers and WiMAX transceivers operating in close proximity to each others.
The present invention will be described with reference to the accompanying drawings. Generally, the drawing in which an element first appears is typically indicated by the leftmost digit(s) in the corresponding reference number.

This patent is subject to a terminal disclaimer.

Wireless transceivers with filter arrangement for WiFi and LTE coexistence


A power supply apparatus includes a plurality of power storage modules that are connected in parallel and a backup power storage module that is connected in parallel with the plurality of power storage modules. When charging or discharging of at least one of the power storage modules is disabled, charging of the other power storage modules is inhibited, discharging of the backup power storage module is permitted, states of charge of the backup power storage module and the other power storage modules are detected, and charging of the backup power storage module and the other power storage modules is permitted in accordance with the detected states of charge.

The present disclosure relates to a power supply apparatus using a battery and a power supply switching method.
In recent years, secondary batteries, such as lithium-ion batteries, have rapidly found extensive application in power storage apparatuses for storing electric power, storage batteries for vehicles, and the like which are combined with new energy systems, such as solar batteries and wind power systems. In order to generate high output power, when many power storage elements, for example, unit batteries (also called battery cells, electric cells, or cells) are used, a configuration is employed in which a plurality of power storage modules are connected in series. A battery block is configured such that a plurality of battery cells, for example, four battery cells, are connected in parallel and/or in series. A power storage module (also called an assembled battery) is configured such that many battery blocks are housed in an exterior case.
There is a power storage system in which a plurality of power storage modules are connected and a control device common to the plurality of power storage modules is provided. A configuration is provided in which each power storage module has a module controller and communication is performed between the module controller and the control device via a communication device.
When the power storage system is used as a power supply, in some cases, a power storage module has to be switched to a backup power storage module even during flow of current. Because it is difficult to turn off, for example, an emergency power supply or a power supply of a base station for mobile phones, switching between the power storage modules is performed during flow of current. However, when batteries that are different in terms of the amount of charge are connected with each other, a large current exceeding a rating flows from a battery having a large amount of charge into a battery having a small amount of charge, and such a current may damage a power storage module.
In terms of switching a power supply to a backup power supply, techniques disclosed in Japanese Unexamined Patent Application Publications Nos. 2002-095173 and 2005-176461 have been suggested in the related art. In the technique disclosed in Japanese Unexamined Patent Application Publication No. 2002-095173, the outputs of two batteries are each connected to a common power supply circuit via a field-effect transistor. When a battery is accidentally disconnected in a state in which power is supplied from the battery to a load, the state is switched to a state in which power is supplied from the other battery to the load.
In the technique disclosed in Japanese Unexamined Patent Application Publication No. 2005-176461, when power supply trouble occurs in a load device operated by direct-current power, direct-current backup power is supplied. There are provided battery packs that each include a plurality of secondary batteries connected in series so that a voltage necessary for the load device is obtained. The life of each battery pack is determined and, when it is determined that a battery pack reaches the end of its life, only that battery pack is taken off and replaced.

Power supply apparatus and power supply switching method


A method for fabricating a cylindrical capacitor is described. Semiconductor device structures, including a capacitor node contact region, are formed on a semiconductor substrate. A first insulating layer is deposited over the device structures and planarized. A silicon nitride layer and then a second insulating layer are deposited over the first insulating layer. A contact opening having a first width is etched through the insulating layers and the silicon nitride layer to the capacitor node contact region. A photoresist mask is formed over the second insulating layer having a mask opening over the contact opening wherein the mask opening has a second width wider than the first width and wherein photoresist residue remains at the bottom of the contact opening. A second opening is etched in the second insulating layer corresponding to the mask opening wherein the photoresist residue protects the semiconductor substrate within the contact opening during etching. The photoresist mask and residue are removed. A first layer of polysilicon is deposited to fill the contact opening. The first polysilicon layer overlying the second insulating layer is polished away to form the bottom electrode of the capacitor. The second insulating layer is removed. A capacitor dielectric layer is deposited over the silicon nitride layer and the first polysilicon layer. A second polysilicon layer is deposited overlying the capacitor dielectric layer to form the top electrode of the capacitor.

(1). Field of the Invention
The present invention relates to a method of fabricating a dynamic random access memory device, and more particularly, to a method of forming a cylindrical capacitor in the fabrication of a dynamic random access memory device.
(2). Description of the Prior Art
Dynamic random access memory (DRAM) devices are widely used in the art. In recent years there has been a dramatic increase in the packing density of DRAMs. Large DRAM devices are normally silicon based, and each cell typically embodies a single MOS field effect transistor with its source connected to a storage capacitor. This large integration of DRAMs has been accomplished by a reduction in individual cell size. However, the reduction in cell size results in a decrease in storage capacitance leading to reliability drawbacks, such as a lowering of source/drain ratio and undesirable signal problems. In order to achieve the desired higher level of integration, the technology must keep almost the same storage capacitance on a greatly reduced cell area.
Efforts to maintain or increase the storage capacitance in memory cells with greater packing densities have included the use of a stacked cylindrical capacitor design in which the capacitor cell uses the space over the device area for the capacitor plates. In U.S. Pat. No. 5,346,844 to Cho et al, there is described a method of forming a cylindrical capacitor using a poly plug process. FIGS. 1 through 4 illustrate such a conventional poly plug process.
Referring to FIG. 1, there is illustrated a partially completed DRAM integrated circuit device in which is shown a semiconductor substrate 10. Semiconductor device structures, such as gate electrodes, not shown, are fabricated in and on the semiconductor substrate and covered with a thick oxide layer 15. A layer 17 of silicon nitride is deposited over the oxide layer. An opening is etched through the silicon nitride and oxide layers and filled with polysilicon which is etched back to form the poly plug 19. This opening is typically 0.3 to 0.35 microns wide. If the opening is too deep, it may be difficult to completely fill the opening. If the polysilicon is not etched back enough, polysilicon residue 21 may be left on the surface of the silicon nitride layer.
Referring now to FIG. 2, a second oxide layer 23 is deposited over the silicon nitride layer and the poly plug. A second photoresist mask is used to provide an opening having a width of between about 0.5 to 0.6 microns. The opening is etched through the second oxide layer 23 to the poly plug 19. A second polysilicon layer 27 is conformally deposited within the opening, as shown in FIG. 3, to form the bottom plate electrode of the capacitor.
If there is misalignment of the second photoresist mask 25, as shown in FIG. 4, the second polysilicon layer 27 does not completely cover the poly plug 19. Next, the polysilicon layer 27 is patterned, and the oxide layer 23 is stripped. If there is misalignment, as in FIG. 4, the portion of the poly plug 33 not covered by the polysilicon layer 27 will be exposed. This is a weak point. The oxide etch, such as buffered oxide etch (BOE) will etch through the weak point 33 and cause peeling of the silicon nitride layer 17 at that point.
Metal plug processes are discussed in ULSI Technology, by Chang and Sze, McGraw-Hill, New York, N.Y., c. 1996, pp. 444-445. U.S. Pat. Nos. 5,409,855 to Jun and 5,554,557 to Koh teach methods of forming cylindrical capacitors without using a poly plug process, but do not address the misalignment and deep recess problems.

Method for forming a cylinder capacitor in the dram process

Taiwan Semiconductor Manufacturing Company, Ltd.


Edge portions of detection electrodes, such as a first linear electrode and a second linear electrode, that include the side surfaces of the detection electrodes and parts of surfaces of the detection electrodes, the surfaces continuing from the side surfaces and facing a photoconductive layer for recording, are covered with dielectrics. Further, surfaces of the detection electrodes and the dielectrics are coated with an anti-crystallization layer to prevent crystallization of a photoconductive layer for readout. At this time, the surfaces of the electrodes are smoothly covered with the dielectrics at angles θ of contact of 5 to 60 degrees so that no bump is present, thereby preventing generation of a crack in the anti-crystallization layer on the dielectrics and the electrodes. Accordingly, crystallization of the photoconductive layer for readout, which is induced by injection of charges from the edge portions of the detection electrodes or the like, is prevented.

1. Field of the Invention
The present invention relates to a radiation image detector for recording radiation images by generating charges by irradiation with radiation and by storing the charges.
2. Description of the Related Art
Conventionally, in the medical field or the like, various kinds of radiation image detectors that record radiation images related to a subject have been proposed and used in practical situations. The radiation image detectors record the radiation images related to the subject by irradiation with radiation that has passed through the subject and output electric signals based on the recorded radiation images.
The radiation image detectors are classified into a direct-conversion type and an indirect-conversion type. In the direct-conversion type, radiation is directly converted into charges and the charges are stored (accumulated). In contrast, in the indirect-conversion type, radiation is temporarily converted into light by using a scintillator, such as CsI:Tl and GOS (Gd2O2S:Tb), and the light is converted into charges in the photoconductive layer. Then, the charges are stored. Further, the readout types of the radiation image detectors are basically classified into a light readout type using readout light and an electrical readout type using a thin film transistor (TFT).
As the light-readout-type radiation image detector, the following radiation image detector is known, for example. In the light-readout-type radiation image detector, charges generated in a photoconductive layer for recording by irradiation with radiation are stored and linear electrodes are charged (electrified) with charges that have the opposite polarity to the polarity of the stored charges. Pairs of charges (charge pairs, dipoles or the like) are generated in the photoconductive layer for readout by irradiation with readout light and the charges of the pairs of charges that have two different polarities are combined with the stored charges and the charges that have charged the linear electrodes, respectively. Accordingly, the stored charges are read out.
As the electrical-readout-type radiation image detector, the following radiation image detector is known, for example. In the electrical-readout-type radiation image detector, charges generated by irradiation with radiation are collected by pixel electrodes for respective pixels and stored in a storage capacity (accumulation capacity) connected to the pixel electrodes. Then, the stored charges are read out, pixel by pixel, by turning on/off electrical switches, such as thin film transistors (TFT's), a charge coupled device (CCD), or a complementary metal oxide semiconductor (CMOS) sensor.
A technique of covering the entire surfaces of pixel electrodes with an insulation coating or a coating made of an insulating substance containing carbon particles or metal particles in an electrical-readout-type radiation image detector is disclosed in Japanese Unexamined Patent Publication No. 2006-156555. In the technique, the pixel electrodes are covered in such a manner to make the surface of the coating smooth (even) and to improve the properties of the coating.
Further, U.S. Pat. No. 5,861,052 discloses a technique of providing a semiconductor that separately covers each of edge portions of the pixel electrodes in an electrical-readout-type radiation image detector. The semiconductor is provided to prevent charges that have once trapped by the pixel electrodes from moving to other pixels electrodes adjacent thereto.
The aforementioned linear electrodes and pixel electrodes are detection electrodes for detecting signals based on charges generated by irradiation with radiation. In such detection electrodes, an electric field tends to concentrate in the edge portions thereof. Therefore, charges tend to be injected into the photoconductive layer from the edge portions of the detection electrodes. As the material for the photoconductive layer, an amorphous (non-crystalline) substance, such as amorphous selenium, is generally used. If excessive charges are injected into the photoconductive layer from the edge portions of the detection electrodes, heat is generated at the portion of the photoconductive layer into which the charges have been injected. Consequently, crystallization occurs in the photoconductive layer. If crystallization occurs in the photoconductive layer, an artifact is generated in a detected image because the electrical property of the crystallized portion and that of the amorphous portion differ from each other. Consequently, the image quality deteriorates.
Such injection of charges can be effectively prevented by covering the pixel electrodes with an insulating substance. Japanese Unexamined Patent Publication No. 2006-156555 discloses structure in which pixel electrodes are covered with an insulation coating. However, the entire surfaces of the pixel electrodes that include not only the edge portions of the pixel electrodes but flat portions of the pixel electrodes are covered. Therefore, the charge transfer characteristic becomes lower and the sensitivity and the residual image characteristic (afterimage characteristic) deteriorate. Japanese Unexamined Patent Publication No. 2006-156555 discloses a technique of covering the entire surfaces of the pixel electrodes with a coating containing particles that have a charge transfer characteristic to improve electrical conductivity. However, in this structure, charges tend to be injected into the photoconductive layer Consequently, crystallization of the photoconductive layer tends to occur.
U.S. Pat. No. 5,861,052 discloses structure in which the edge portions of the pixel electrodes are covered with a semiconductor. The electrical conductivity of the semiconductor is high. Therefore, the sensitivity and the residual image characteristic do not deteriorate, but the amount of charges injected into the photoconductive layer increases. Therefore, the structure is not effective to prevent crystallization of the photoconductive layer.
Further, even if injection of excessive charges into the photoconductive layer is reduced, there is a problem that crystallization of the photoconductive layer occurs and progresses by using the radiation image detector repeatedly.


A particle counter for counting a number of particles in an air sample includes a sampling probe connected to a counter body with an intake section of the sampling probe having an adjustable area. The intake section is constructed of a plurality of telescopically interconnected shaped pieces that slide within one another to permit lengthening and shortening. The degree of lengthening or shortening determines the adjustable area of the sampling probe, which corresponds to an air speed of the air sample to provide precise particle measurements.

1. Field of the Invention
The present invention relates to a particle counter having an adjustable probe, and more particularly, to a particle counter having an adjustable probe that is capable of reducing particle count measurement errors by varying the intake area of a sampling probe according to the speed of the air within a clean room to be measured.
2. Discussion of the Related Art
Present manufacturing processes and methods require ultra-precision, high-purity, and contamination free environments. Technology related to cleaning and reducing contaminants in the manufacturing process substantially improves the performance and the production yield of many present day products.
Clean rooms, in particular, have been used widely in many industries, including: the electronics industry for such products as semiconductors and liquid crystal displays; the precision instrument field; the chemical field, especially when manufacturing chemicals for semiconductor devices where chemical purity is important; and hospitals, medical supply factories, and the food industry where microbe pollution becomes an issue.
In particular, clean rooms in the semiconductor industry seek to control the amount of particles floating in the air so that the particles do not reach and contaminate the working object in the space. In the clean room, the temperature, humidity, interior pressure, illumination, noise and vibration, etc. are controlled and managed simultaneously. Clean room management is based on relative degrees or classes of cleanliness, as determined by the concentration and diameter of particles existing in the space.
Various measurement apparatuses have been developed to facilitate clean room management. One such measurement apparatus, a condensation particle counter, operates under the principle that the particle size increases during an alcohol evaporation process. Another measurement apparatus, an optical particle counter, measures the intensity of light scattered by the particles after projecting a laser into the sampled air containing the particles.
FIG. 1 is a perspective view showing a conventional optical particle counter. In the particle counter 10, a counter body 12 and a sampling probe 20, for sampling the air containing particles, are connected via a sampling tube 18. Formed in the counter body 12 are a display section 14, which is capable of displaying a measurement result, and an adjusting section 16, which is capable of adjusting a switch or setting a value. Also, a pump (not shown) is operated to suction the air to be measured through the sampling probe 20. A laser tube (not shown) projects the laser light into the sampling air to be measured, and a photo detector (not shown) detects the scattered laser light caused by collisions between the projected laser light and particles.
FIG. 2 is a perspective view showing the conventional sampling probe 20 of FIG. 1 in greater detail. A handle 22 is provided at the connection point between the funnel-shaped sampling probe 20 and the sampling tube 18 so that an operator can hold it while taking particle measurements. The interior wall 21 of the sampling probe 20 is flat.
In operation, a technician orients the sampling probe 20 toward a specific flow direction of the air to be measured in order to sample the air. It is preferable that the air speed as suctioned by the pump through the intake 23 of the sampling probe 20 should coincide with the air speed of the atmosphere in close proximity to the probe 20. When the air speed of the atmosphere to be measured does not coincide with the air speed at the intake 23 of the probe 20, measurement errors occur. As a result, the cleanliness management of the clean room is less than optimal.
FIGS. 3A, 3B and 3C illustrate various air flows that result according to the relationship between an interior air speed (hereinafter referred to as `probe air speed`) at the intake 23 of the probe 20 and the atmospheric air speed in close proximity to the probe 20.
FIG. 3A depicts the situation where the atmospheric air speed is greater than the probe air speed, FIG. 3B depicts the situation where the atmospheric air speed is less than the probe air speed, and FIG. 3C depicts the situation where the atmospheric air speed is equal to the probe air speed.
As shown by the arrows in FIG. 3A, when the atmospheric air speed, as generated by a clean air circulating pump (not shown) for the clean room system, is greater than the probe air speed generated by a sample suction pump within the air particle counter 10, outward eddy flows 26 are generated near the edges of the intake area 23 of the probe 20. The lower pump suction pressure causes particles that would normally have been suctioned into the probe 20 to be scattered away from the probe 20 by the outward flowing eddies 26. Accordingly, the number of particles entering the probe 20 and measured by the particle counter 10 are decreased, resulting in measurement errors and decreased reliability in the management of the clean room.
As shown by the arrows in FIG. 3B, when the atmospheric air speed, as generated by a clean air circulating pump (not shown) for the clean room system, is less than the probe air speed generated by a sample suction pump within the air particle counter 10, inward eddy flows 26 are generated near the edges of the intake area 23 of the probe 20. However, in this case, the higher pump suction pressure causes particles that would normally not have been suctioned into the probe 20 to be suctioned into the probe 20. Accordingly, the number of particles entering the probe 20 and measured by the particle counter 10 are increased, resulting in measurement errors and decreased reliability in the management of the clean room.
The preferred or optimum case would be as shown in FIG. 3C where the atmospheric air speed is equal to the probe air speed, whereby the correct amount of particles enter the probe 20, thereby minimizing measurement errors.
Present air particle counter probes have intakes that are manufactured to a general specification based on an average air speed of a typical clean room. For example, an air particle counter may be designed to sample the air at a speed of 1 cubic foot per minute according to an international standard. Accordingly, for a probe having an intake diameter of 3 cm, the probe air speed should be 0.667 m/sec for optimum results.
However, the air speeds in clean rooms for a semiconductor production are different, ranging from 0.1 m/sec to 0.7 m/sec, for example. A problem thus exists since the precise number of particles cannot be measured with the conventional fixed intake sampling probe, except for the one condition where the atmospheric air speed precisely matches the probe air speed. Since the various types of clean rooms in other industries also have different air speeds according to the type and function of the clean room, the above problem is continuously evident throughout the art.

Particle counter with sampling probe having adjustable intake area


Provided is a storage receptacle stacking system comprising a set of receptacles. Each receptacle is an open rectangular prism defined by, a back panel, which has a top edge, a bottom edge, a right edge, and a left edge, and a first back panel surface, and a set of side panels. The set of side panels has top, bottom, left, and right panels. Each receptacle is removably engaged to at least one other receptacle by a first set of fasteners. For each receptacle, at least one of the panels in the set of side panels is adjacent to and parallel with at least one of the panels in the set of side panels of another receptacle, and any one of the panels in the set of side panels may be engaged in the alternative with any one of the panels in the set of side panels of any other receptacle.

It is desirable to provide storage articles, in particular, open box style five-sided receptacles. These open receptacles may be used for storage and these receptacles may be stacked to provide a stacked storage system.
Ready to assemble furniture has been around since the late 1940s. Companies such as Sauder have been producing ready to assemble items since the 1950s.
It remains desirable to provide a ready to assemble storage receptacle stacking system.


A wafer having an interlayer insulating film on a silicon substrate and an Al alloy layer on the interlayer insulating film coated with a resist pattern is introduced into an etching chamber where the Al alloy layer is selectively etched in etchant gas plasma. A main etching process is performed under the etching conditions of a high plasma density until the interlayer insulating film 12 is exposed, and a succeeding over etching process is performed under the etching conditions of a low plasma density. A dry etching method and system is provided which can suppress generation of an abnormal shape or notch of a wiring pattern etched in low pressure and high density plasma, without sacrificing etching selectivity and with productivity being maintained high.

a) Field of the Invention
The present invention relates to a dry etching method and apparatus for patterning a fine conductive wiring layer of a semiconductor integrated circuit or the like by using etchant gas plasma.
b) Description of the Related Art
Wafers for semiconductor integrated circuits are nowadays becoming large in diameter and have finer wiring patterns. In place of batch processing systems which process a plurality of wafers at the same time, single wafer processing systems have been used recently which process one wafer at a time in order to reduce process variations among wafers. For example, in the case of a plasma etching system, it is essential to use a high plasma density in order to ensure practical productivity of a single wafer processing system. From this reason, ECR (electron cyclotron resonance) plasma, helicon wave plasma, inductively coupled plasma, and the like are used for plasma etching systems.
An amount of etching species (active species) in high density plasma is large so that a high etching efficiency is obtained and a productivity higher than that at a low density plasma can be obtained. However, since a high gas pressure is used for a conventional RIE system in order to obtain high density plasma, the mean free path of ions becomes short. Therefore, etching anisotropy is lowered. If high ion energy is used to maintain anisotropy, etching selectivity of resist, underlying insulating layer, and the like is degraded. For realizing both a good productivity and a good etching anisotropy, plasma etching system of low pressure and high density has been developed which can independently control plasma density and ion energy and can maintain high etching anisotropy by lowering ion energy.
However, if polysilicon is etched by using plasma of a low pressure and a high density at a low ion energy, the bottom of a patterned silicon layer near at the interface to the underlying layer is locally side etched and an abnormal shape called a notch is formed. This phenomenon is reported, for example, in the following papers:
(1) N. Fujiwara, et al: Proc. 15th Symp. Dry Process, (1993) 45; PA0 (2) D. Takehara, et al: Proc. 15th Symp. Dry Process, (1993) 51; PA0 (3) N. Fujiwara, et al: Proc. 16th Symp. Dry Process, (19934) 31; PA0 (4) T. Nozawa, et al: Proc. 16th Symp. Dry Process, (1994) 37; and PA0 (5) D. Kimura, et al: Proc. 38th Symp. Semiconductors and Integrated Circuits Technology, pp. 91-96 (1995).
The following facts of the abnormal shape called a notch are known. A notch is formed at an area where fine lines with narrow adjacent spaces are densely distributed (hereinafter called a line and space (L & S) structure). A notch is not formed at the L & S structure having a plurality of lines connected in common, but it is observed at an outer line of an isolated L & S structure. A notch is not observed in the state of just etching but it is observed in the state of over etching. The cause of a notch may be ascribed to disturbance of ion orbits by charge-up of the L & S structure during plasma etching, or to other reasons.
An abnormal shape reported to date is formed in polysilicon during plasma etching at a low pressure and a high density. A similar abnormal shape has also been confirmed when Al alloy is etched at a low pressure and a high plasma density to pattern a fine L & S structure. FIG. 8 shows a test pattern of Al alloy used by notch observation experiments. This test pattern has an L & S structure including wiring patterns (lines) L1, L2, . . . , L7 of 1 .mu.m width being disposed with a space of 0.8 .mu.m between each pair of adjacent lines (L/S=1.mu.m/0.8 .mu.m). The center wiring pattern L4 is connected to an antenna 84 having a length of about 130 mm and a space of, for example, 10 .mu.m or wider.
FIG. 9 is a cross sectional view of the wiring structure of FIG. 8 taken along line A-A'. On an insulating film 81 such as a silicon oxide film deposited on a silicon substrate 80, an Al alloy layer 82 is formed on which a resist mask 83 is formed. The substrate 80 is introduced into a plasma etching system and the Al alloy layer 82 is selectively etched to form an L & S structure shown in FIGS. 8 and 9. The etching rate becomes lower at the narrow space than at the broad space. When the underlying insulating film 81 is exposed at the broad space, the Al alloy layer 82 is still left at the narrow space in the L & S structure 86 with dense wiring patterns. If over etching is performed until all the unnecessary Al alloy layer 82 is removed, notches 85 are formed, as shown in FIG. 9, at the bottoms of the wiring pattern L4 connected to the antenna 84 and of the outermost wiring patterns L1 and L7 on the pattern dense side.
Similar notches are also observed when the wiring pattern L4 is connected to the substrate 80 via a contact 87 instead of being connected the antenna, as shown in FIG. 8, and is subjected to etching.
Generation of similar notches is also recognized by any one of plasma etching systems of low pressure and high density, such as an inductively coupled plasma etching system and a microwave plasma etching system (in particular, electron cyclotron resonance (ECR) plasma etching system).
In order to prevent notches, etching may be performed at a plasma density lower than an ordinary case or at a high ion energy with a high plasma density. However, at a low plasma density, the etching rate is lowered. This contradicts the primary object of obtaining high productivity at a high plasma density. Etching anisotropy is degraded at a high pressure. If ion energy is raised in order to maintain high anisotropy, etching selectivity is lowered so that a wiring process margin becomes small, and/or production yield is lowered.
Instead of using a low pressure and high density plasma etching system, a lower plasma density RIE system may be used for effectively preventing notches. Also in this case, however, the etching rate is lower than the low pressure and high density plasma etching system, and high productivity is impossible. If the pressure is raised in order to increase the amount of active etching species, etching anisotropy (directivity) is degraded. If gas such as flon (fuorocarbon) gases easy to form a side wall protection film is added in order to maintain high etching anisotropy, a great amount of reaction byproducts are attached to the inner wall of an etching chamber.

Dry etching suppressing formation of notch


In an ink remaining amount checking routine to be performed at every one line of printing, when a flag indicative of the ink amount in a sub-tank less than or equal to a predetermined amount, an alarm is generated. Also, while the flag is set, predetermined number of lines capable of printing is performed. Thereafter, ink is supplied. By this, operator may check alarm for ink supply and perform ink supply at a predetermined time interval.

1. Field of the Invention
The present invention relates generally to a printing apparatus. More specifically, the invention relates to an ink-jet printing apparatus for textile printing performed by ejecting ink toward a cloth.
2. Description of Prior Art
In a printing apparatus employing an ink as printing agent, an ink is generally supplied at the timing where the ink provided at a predetermined amount in the printing apparatus is used out or the remaining amount of the ink becomes small. Supplying of ink is performed by exchanging an ink cartridge storing ink to new one or by supplying the ink to an ink tank to refile it.
In the printing apparatus, such ink supply operation is enabled by stopping printing operation in response to an ink supply command automatically generated by detecting spending out of the ink or manually entered by the operator, for example. However, in typical printing apparatus, even when such ink supply command is detected, on-going printing operation at the detection is continued and printing operation is terminated after completion of printing operation, for the current page, for example, for enabling ink supply. Namely, since the conventional printing apparatus has a margin of remaining amount of ink upon detection of spending out, the foregoing process should not cause any significant problem.
However, when an elongated rolled paper or cloth (a continuous printing medium) is used as printing medium, the amount of image to be continuously printed is relatively large. In such case, even after detection of the ink supply demand, state it is likely to require printing for large amount of image, and the printing operation of non-ink state likely exists and continues for a long time. In such case, it is possible to cause failure in a printing head or so forth. Particularly, in case of so-called bubble-jet printing apparatus employing an ink-jet head assembly, in which the ink-jet head generates bubble in the ink utilizing heat energy and the ink is ejected by generation of the bubble, continuing of printing under the condition where the ink is spent out, may results in damaging of the head.
As a solution for this, it may be considered to terminate printing operation at the timing of spending out of the ink for supplying ink. However, this should make on-going printing incomplete to waste printing medium and ink. Also, in case of large amount printing, the printing period spent becomes wasted to cause degradation of efficiency.
As another solution, for example, an ink reservoir is provided at a location out of motion range of the printing head and so forth in printing operation, and is connected to the printing head by means of movable tube or so forth. With such arrangement, when shorting of ink is detected by a ink remaining amount sensor, the operator may supply new ink to the ink reservoir so that printing operation can be continued without interruption and without causing possibility of damaging of the head.
However, even in this case, upon shorting of ink, for instance, at the occurrence of alarm signal of the ink remaining amount sensor upon detection of shorting of ink, ink supply operation per se is inherent. Also, since the printing operation will never stop, when continuous printing is to be performed for long period, the operator should monitor shorting of the ink throughout the printing period so that the ink can be instantly supplied at the occurrence of shorting of the ink.


An ice making device may include an ice tray; a drive part which is provided with an output shaft to which the ice tray is attached and in which the ice tray is turned by turning of the output shaft; and a frame body to which the drive part is attached. A twisting operation is applied to the ice tray during a turning operation for separating ice pieces from the ice tray. The drive part may include a drive side attaching part. The frame body may include a frame body side attaching part. The frame body side attaching part and the drive side attaching part are fitted to each other along a direction that is perpendicular to the output shaft, thereby attaching the drive part to the frame body.

Conventionally, a refrigerator such as a household refrigerator has been known which is provided with an ice making function in which ice pieces are manufactured and manufactured ice pieces are supplied to an ice storage container for storing ice pieces that is arranged within the refrigerator.
As this type of an ice making device, for example, the ice making device described in Patent Literature 1 and the like has been known. Specifically, as shown in FIG. 8(a), an ice making device 60 is disclosed which is provided with an ice tray 61 for manufacturing ice pieces, a turning drive part 62 which turns the ice tray 61 to make manufactured ice pieces drop from the ice tray 61, and a frame body 63 to which the ice tray 61 and the turning drive part 62 are attached.
[PTL 1] Japanese Patent Laid-Open No. 2001-165538
In the ice making device 60 shown in FIG. 8(a), in order to attach the ice tray 61 and the turning drive part 62 to the frame body 63, the following method is conceivable. In other words, as shown in FIG. 8(b), one end 61a of a turning shaft of the ice tray 61 is inserted into a through hole 63a of the frame body 63 and the one end 61a of the turning shaft is supported by the frame body 63. After that, while the other end 61b of the turning shaft of the ice tray 61 is fitted to an output shaft 62a of the turning drive part 62, a fixing pawl piece 62b of the turning drive part 62 is inserted into a pawl piece fixing part 63b of the frame body 63. In this case, the fixing pawl piece 62b is deformed to be inserted into the pawl piece fixing part 63b. However, it is difficult for the fixing pawl piece 62b and the pawl piece fixing part 63b to secure a sufficient strength which is capable of enduring the deformation.
On the other hand, for example, a method may be conceivable in which the output shaft 62a of the turning drive part 62 is fitted to the other end 61b of the turning shaft of the ice tray 61 while the turning drive part 62 is slid in a direction of the arrow "A" in FIG. 8(a) (direction of the output shaft 62a of the turning drive part 62). However, in this case, for example, the following design change is required. In other words, a wall part located on an outer side in the direction of the output shaft 62a of the turning drive part 62 is removed, or the frame body 63 is extended to the outer side to secure a space so that the turning drive part 62 is capable of sliding. When the wall part located on the outer side in the direction of the output shaft 62a of the turning drive part 62 is removed, the strength of the frame body 63 is decreased and thus this design change is difficult. Alternatively, when a space where the turning drive part 62 is capable of sliding is provided, after the output shaft 62a has been fitted to the other end 61b, a dead space is formed on the outer side of the turning drive part 62 in the direction of the arrow "D" and thus the size of the ice making device 60 is unnecessarily made larger in the direction of the output shaft 62a of the turning drive part 62.


An integral circulating fluidized bed steam generation system having a particle separator which is formed by the membrane walls of the reactor chamber. The particle separator has a serpentine configuration which includes a first turn which is capable of causing the solid particles in the flue gas to move toward the rear membrane wall and a second turn which is capable of causing smaller sized solid particles and the flue gas to be disposed between the front membrane wall and the larger sized solid particles wherein the flue gas passes through the solid particles to a discharge conduit which is disposed within the rear membrane wall and wherein the smaller sized solid particles are retained between the front membrane wall and the larger sized solid particles. The particle separator also includes a means for recycling the solid particles from the particle separator to the reactor chamber.

The use of circulating fluidized bed systems for burning carbonaceous materials to generate steam from heat exchangers disposed within fluidizing reactors is well documented throughout the literature.
Circulating fluidized bed systems involve a two phase gas-solids process which promotes solids entrainment within the upflowing gas stream in the reactor chamber and then recycles the solids back into the reactor chamber with a high rate of solids circulation. The rate of solids circulation in the circulating fluidized bed process is about fifty times that of a bubbling bed process. Circulating fluidized bed systems differ from bubbling bed systems in that they typically employ air to move the fuel in a circulating path as it combusts which increases turbulence, residence time, and a higher bed temperature in contact with the heat absorbing surfaces throughout the combustor system, thus increasing carbon combustion efficiency, increasing heat transfer throughout the system and decreasing carbon monoxide emission levels.
Various examples of known circulating fluidized bed systems are described in U.S. Pat. Nos. 4,165,717 (Reh et al.) and 3,625,164 (Spector), and an article by A.M. Leon and D.E. McCoy, presented at the First International Conference on Circulating Fluidized Beds, Halifax, Nova Scotia, Canada (Nov. 18-20, 1985), and entitled "Archer Daniels Midland Conversion to Coal."
Common to all circulating fluidized bed systems is the need for a fluidized bed reaction chamber or combustor, a solids separation unit and a solids re-injection unit. All of the circulating fluidized bed systems disclosed in the above patents and article have particle separators (i.e., cyclones) and solids re-injection units (i.e., FluoSeals.RTM.) which are disposed external of the reaction chamber.
In most conventional systems the combustor, particle separator and solids re-injection unit are supported independently. Thus, requiring their own structural support systems, refractory protected flue gas ducts with expansion joints and in some designs separate water-cooled or steam-cooled systems with their own supply and relief piping.
Still other have attempted to provide a combustor reactor having a particle separator disposed within the reactor chamber. Some examples of these integral combustor/separator systems are shown in U.S. Pat. No. 4,546,709 (Astrom), which issued on Oct. 15, 1985, U.S. Pat. No. 4,301,771 (Jukkola et al.), which issued on Nov. 24, 1981, U.S. Pat. No. 5,117,770 (Hassinen), which issued on Jun. 2, 1992, and U.S. Pat. No. 5,070,822 (Kinni et al.), which issued on Dec. 10, 1991.
The Astrom patent discloses a reaction chamber with a fluidized bed and a cyclone separator disposed within the reaction chamber in order to attain a high degree of separation, which is desirable if the gases are to pass through a turbine.
The Jukkola et al. patent discloses a fluidized heat exchanger which comprises a housing, a reaction chamber and a convection heat exchange chamber above the reaction chamber. The convection heat exchange chamber is separated from the reaction chamber by a slanted baffle. The baffle defines a gas passageway between the reaction chamber and the convection heat exchange chamber. At the bottom of the baffle is a hopper portion wherein dust is collected and removed from gases passing through the convection heat exchange chamber.
The Kinni et al. and Hassinen patents each disclose a reactor chamber having a particle separator disposed therein. The particle separator has an outer casing and an inner casing. These casings both have a circular horizontal cross-section and center lines which are arranged essentially to coincide with the center line of the reactor chamber.
The Astrom, Kinni et al. and Hassinen patents each require that an independent particle separator unit be built and installed within the reaction chamber. This is extremely costly, technically difficult to install and extremely difficult to service.
The baffle design of Jukkola et al. relies solely upon gravity for particle separation of large particles, but does not provide sufficient means for separating fine particles from the flue gases. That is, the combustion gases exiting the combustion chamber have entrained therein a substantial amount of dust. In traversing the convection chamber the larger particles of unburned fuel, ash and limestone drop out and are collected by the hopper. These particles slide down the inclined surfaces of the baffle and hopper into the ash conduit for recycling into the fluidized bed. The gases leaving the reactor vessel through the exhaust gas conduit will have entrained therein a substantially reduced amount of fine dust but it may be desirable to provide a cyclone external to the reaction vessel to capture these fine solids and return them to the fluidized bed through a cyclone return conduit. Therefore, the slanted baffle of Jukkola et al. does not remove sufficient amounts of fine particles to avoid the need altogether of an externally disposed cyclone or particle separator. Moreover, the fluidized bed boiler of Jukkola et al. is directed primarily to a bubbling bed system rather than to a circulating fluidized bed system and is not concerned with the recycling of a substantial portion of entrained solid particles since it does not generate nearly as much entrained solid particles as normally associated with a circulating fluidized bed system.
The present invention is directed to a circulating fluidized bed boiler system which is a single integrated or integral fluidized bed reactor, solids separation unit and solids re-injection unit. These three normally separate and independent components are combined into a single integral system within the water-cooled combustor system. The present inventor has discovered that incorporating these components into a single integral system simplifies the structural support and eliminates the high maintenance refractory lined breeching with expansion joints.
The integral circulating fluidized bed boiler system according to the present invention also provides the following advantages over conventional multiple component systems: (1) lessens the complicated structural supports for the various units, (2) eliminates expansion and sealing problems between the reactor and particle separator and between the solids re-injection unit and the reactor, (3) reduces the cost of manufacturing and field construction, (4) reduces the required plan area thus saving real estate costs, (5) provides a larger range of boiler applications, (6) reduces maintenance costs and requires that fewer replacement parts be stocked, and (7) simplifies the exterior maintenance platforms and walkways.
Also, the unique arrangement of the system of the present invention allows the conventional back-pass convection superheater/economizer unit to be incorporated into the water-cooled membrane enclosure thus providing one uniformly expanding singularly supported piece of equipment.
The present invention also provides many additional advantages which shall become apparent as described below.

Integral water-cooled circulating fluidized bed boiler system


A passive noise reduction apparatus has a headset with at least one ear cup attached to the headset, the ear cup having an ear side and a shell side. An inner shell, having a cup side and an outer side, is mounted to and substantially covers the shell side of the ear cup wherein the cup side of the inner shell faces the shell side of the ear cup. An outer shell, having an inner side and a distal side, is mounted to and substantially covers the inner shell, wherein the inner side of the outer shell is in substantially contiguous contact with the outer side of the inner shell.

A number of applications exist for devices that can reduce ambient noise levels for individuals. Many occupations expose employees to high noise levels and, for the protection of employees auditory senses, equipment is required that can reduce the ambient noise levels to which those employees are exposed. In addition, individuals often use headphones while listening to music. The quality of the music listening is enhanced if the headphones utilized are capable of blocking or reducing ambient noise. Further, headsets are regularly used for telecommunication devices. The individuals using telecommunication headsets can communicate more easily if they have a device for blocking out or reducing ambient noise. In addition to the above-mentioned additional applications also exist for devices that can reduce ambient noise levels for individuals.
Headphones and headsets exist in the art that reduce ambient noise levels via use of electrical circuitry. Unfortunately, such manner of ambient noise reduction is costly and not entirely effective. Common passive noise reduction headphone design involves constructing a single hard shell on the earpiece of the headphones. In this design, ambient noise sound waves must permeate the single hard shell. However, sometimes these single hard shells are not capable of blocking out a significant portion of the ambient noise. Ideally, the hard shell design could be augmented to create a more effective passive noise reduction device.
Another problem with existing headphones and headsets, having the passive noise reducing hard shell, is the headphones and headsets are primarily produced with an unimaginative and unoriginal appearance. Most of these devices have a hard, rounded, exterior shell in some variation of black. Part of the problem is that other colors, while more imaginative, are not appropriate for professional settings or are otherwise aesthetically dissatisfying. Ideally, these headphones and headsets could be constructed with a more imaginative and original appearance, while maintaining a style that is aesthetically pleasing and appropriate for a professional setting.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.

System and method for providing passive noise reduction


The invention relates to a rotary canister base comprising a loudspeaker, a drinking pipe and an air-intake pipe, wherein the loudspeaker serves as a communicating tool and the drinking pipe, which may be connected to a canteen, are all arranged within the confined space of the canister base. In addition, the drinking pipe, when unused, may be fixed onto the canister base. Most importantly, the air-intake pipe connected to the canister can be rotated and positioned at different angles so that the wearer may adjust the direction of the canister to avoid interference with the ambient space when fleeing for life.

1. Field of Invention
The invention relates to a canister base of a mask, which is mounted on the oral and nasal part of the mask with an air-intake pipe connected to the canister. The air-intake pipe may be rotated and thereby the direction of canister is adjusted to adapt to the ambient space.
2. Description of the Related Art
A mask generally includes three primary components: a mask body, a canister, and a canister base connected to the mask body and the canister. The canister base may further comprise a loudspeaker, a drinking pipe, and an air-intake pipe.
The loudspeaker serves as a communication tool for the wearer. Since the air in the mask is blocked therein by the mask, the wearer's voice is mostly isolated from propagation. Thus, a loudspeaker is needed to amplify the sound to make it audible.
The drinking pipe is provided to serve the needs of the wearer of the mask when the wearer has to wear the mask for a long period of time. The drinking pipe extends out from inside of the canister base. When in use, one end of said drinking pipe is put into the wearer's mouth while the other end is connected to a canteen. When unused, the drinking pipe may be fixed onto the canister base.
The air-intake pipe is used in combination with the canister. Contaminated or toxic air becomes clean and non-toxic after filtered by the filter contained in the canister and then flows into the canister base through the air-intake pipe.
The canister usually protrudes substantially from the mask and takes up substantial space. In a confined space, a protruding canister often causes interference and hinders the wearer's action of fleeing or lifesaving.
There are about two viable ways to avoid interference on the canister. One is to manufacture a smaller canister without reducing its filtering efficiency. The possibility to reduce the size of a canister can be expected if more efficient filtering material is developed and larger filtering area can be packed into the limited space in a filter. Another feasible way is make the canister adjustable in orientation to adapt to the confined space where the wearer is in. And thus, the canister may still be adapted to the space without changing its volume.

The 204th Arsenal, Materiel Production Center, Armament Bureau, M.N.D.


A pallet comprises a deck having an upper support surface; a plurality of support members depending from the deck; pallet stacking structure for retaining a second pallet stacked on the pallet, and tray retaining and stacking structure for retaining a tray on the pallet. The pallet stacking structure includes a plurality of first recessed regions formed in the upper support surface for receiving support members of a second pallet stacked on the first pallet. The tray retaining and stacking structure includes a plurality of second recessed regions formed in the upper support surface of the pallet for receiving the legs of a tray when the tray is supported on the pallet. The second recessed regions are formed within the outer boundaries of the first recessed regions and are deeper than the first recessed regions. The depths of the second recessed regions are slightly less than a length of the tray legs such that the bottoms of the tray legs touch the floors of the second recessed regions to transfer the weight of the trays downwardly through the tray legs and to the pallet rather than through the upper support surfaces of the tray.

Pallets are often used for supporting and moving various types of articles. Pallets may be constructed from many different materials, including wood, metal, fiberglass or plastic, and are typically designed to be loaded and moved by forklifts, hand trucks, cranes or other specialized handling or loading equipment.
Most pallets have a deck with an upper support surface and a number of support members depending from the deck to elevate the deck and hence the articles supported on its upper surface above the ground to prevent moisture, dirt and other debris from coming into contact with the supported articles. When not in use, the pallets are often stacked to conserve floor space. Some pallets are therefore formed with pallet stacking structure that supports and stabilizes multiple pallets when stacked.
Pallets are often used to support trays that may be used to hold miscellaneous small objects such as fruit. The trays typically have an upper support surface with a circumscribing outer lip or wall and a number of legs that depend from the support surface to support the upper support surface above a pallet or other surface. The trays are typically designed to be stacked on top of one another such that a number of the trays may be supported on a single pallet. Unfortunately, when multiple trays are stacked on a pallet in this manner, the weight of the trays and the parts held in the trays can exert tremendous forces on the trays at the bottom of the stack and damage the trays. Such damage can be exacerbated by the pallet stacking structure described above because it often interferes with the proper placement and alignment of the trays on the pallet.


A system for conditioning the air within an enclosure which houses heat producing equipment. The system includes a passive heat removal system, for precooling the air, and a thermoelectric temperature control system used in conjunction with the passive heat removal system to achieve additional cooling, temperature control and heating. The passive heat removal system includes a heat pipe system. A power control system includes a programmable control means which receives signals, from a temperature sensor, which are indicative of the temperature of the air in the enclosure. Based upon these signals, the power control system controls the activation of thermoelectric devices in the thermoelectric temperature control system and controls the activation of fans to remove a desired amount of heat from the air in the enclosure and discharge the unwanted heat to the outside air. A switching device operates to apply battery power to the power control system if the electrical power source for the thermoelectric temperature control system fails. A polarity reversal circuit reverses the DC polarity of the DC voltage applied to the thermoelectric devices to reverse the heat pumping of the thermoelectric devices in the situation where the air in the enclosure needs to be heated. Circuitry and sensors are provided to monitor the speed of the fans to detect any failure of a fan. A current control circuit supplies power to and temperature control of thermoelectric cooling devices.

1. Field of the Invention
The present invention relates to air conditioning systems, and more particularly, but not by way of limitation, to a passive heat removal system in conjunction with a thermoelectric temperature control system for conditioning the air in an enclosure which shelters heat producing equipment such as a microwave repeater station, or electronic equipment sheltered in a remote location, or other sealed enclosure such as an automobile.
2. History of the Prior Art
Heat producing equipment such as, for example, remote microwave repeater stations or remote cell sites for cellular phone systems, are frequently subjected to very high ambient temperatures which may have an adverse affect on the life, reliability and/or performance of the equipment. Several systems are available for the cooling or conditioning of the air in the electronic enclosures. The technology used for cooling relate to and include passive cooling systems, conventional compressor-based systems and thermoelectric systems.
In passive cooling systems, the air to be cooled is circulated over an air-to-air heat exchanger, which includes folded, finned heat exchangers, heat pipes, etc. The heat is then exchanged with the outside ambient air. As the amount of heat to be removed from the enclosure increases, the size of the air-to-air heat exchanger must be increased in size, which may be a drawback. Another drawback of the passive cooling system is that the amount of heat the system can remove from the enclosure is determined by the ambient temperatures of the air surrounding the enclosure. Therefore, if the ambient temperature is at, for example, 55.degree. C., the temperature inside the enclosure can only be lowered to a temperature slightly above the ambient temperature by the passive cooling system.
Compressor based systems function by using a refrigerant and the cooling function is achieved by the compression and expansion of the refrigerant. The compressor based systems are efficient but are bulky, have large maintenance costs and consume large amounts of electricity. Also, all the cooling is done actively, which may not be necessary when, for example, the ambient outside air is sufficiently cool.
Thermoelectric temperature control systems use thermoelectric devices that pump heat using the Peltier effect. The thermoelectric devices are highly reliable and very economical at low wattage applications. As the number of watts to be removed are increased, the cost of this type of system increases as the cost is directly related to the number of thermoelectric devices that are needed for the particular function. The cooling capacity may be limited because of the power supply requirements since more thermoelectric devices necessitates more power.
The most typical thermoelectric device incorporates a thermoelectric module/component that utilizes electrical current to absorb heat from one side of the module and dissipate that heat on the opposite side. If the current direction is reversed, so is the heat pumping. Generally, cold sides and hot sides are developed necessitating an effective means of removing or adding heat from or to a solid, liquid or a gas (typically air).
It would be advantageous to provide a system which would condition the air in the electronic enclosures in an improved manner which would be low cost, reliable, efficient and low maintenance.
The present invention provides such an improvement over the prior art by eliminating the need for refrigerant while providing high energy efficiency with improved cooling capacity, low maintenance, low cost and low noise, and which is light weight and compact.

Hybrid air conditioning system and a method therefor


A method and apparatus are provided. The method includes establishing a pathway from a first transceiver to a second transceiver, determining a power level at the second transceiver, and determining whether the power level at the second transceiver is at an acceptable level over the pathway. The method also includes adjusting a power level at the first transceiver in response to determining whether the power at the second transceiver is at the acceptable level. The apparatus includes a first and second logic. The first logic is capable of establishing a pathway with a transceiver. The second logic is capable of determining a power level at the transceiver, determining whether the power level at the transceiver is at an acceptable level over the pathway, and adjusting a power level of the apparatus in response to determining whether the power at the transceiver is at the acceptable level.

1. Field of the Invention
This invention relates generally to telecommunications devices, and, more particularly, to a method and apparatus employing a cutback probe. Specifically, the present invention relates to a method and apparatus employing a politeness and off-hook cutback probe.
2. Description of the Related Art
In communications systems, particularly telephony, it is common practice to transmit signals between a subscriber station and a central switching office via a two-wire, bi-directional communication channel. The Plain Old Telephone System (POTS), designed primarily for voice communication, provides an inadequate data transmission rate for many modem applications. To meet the demand for high-speed communications, designers have sought innovative and cost-effective solutions that take advantage of the existing network infrastructure. Several technological advancements have been proposed in the telecommunications industry that make use of the existing network of telephone wires. One of these technologies is the xDSL technology. DSL technology uses the existing network of telephone lines for broadband communications. An ordinary twisted pair equipped with DSL interfaces can transmit videos, television, and high-speed data.
DSL technologies typically leave the POTS service undisturbed. Traditional analog voice band interfaces use the same frequency band, 0-4 Kilohertz (kHz), as telephone service, thereby preventing concurrent voice and data use. A DSL interface, on the other hand, operates at frequencies above the voice channels from 100 kHz to 1.1 Megahertz (MHz). Thus, a single DSL line is capable of offering simultaneous channels for voice and data.
DSL systems use digital signal processing (DSP) to increase throughput and signal quality through common copper telephone wire. Certain DSL systems provide a downstream data transfer rate from the DSL Point-of-Presence (POP) to the subscriber location at speeds of about 1.5 Megabits per second (MBPS). The transfer rate of 1.5 MBPS, for instance, is fifty times faster than a conventional 28.8 kilobits per second (KBPS) transfer rate.
One popular version of the DSL technology is the Asymmetrical Digital Subscriber Line (ADSL) technology. The ADSL standard is described in ANSI T1.413 Issue 2, entitled, xe2x80x9cInterface Between Networks and Customer Installationxe2x80x94Asymmetric Digital Subscriber Line (ADSL) Metallic Interface,xe2x80x9d the most recent revision of which as of the filing date of this specification is incorporated herein by reference in its entirety.
ADSL modems use two competing modulation schemes: discrete multi-tone (DMT) and carrierless amplitude/phase modulation (CAP). DMT is the standard adopted by the American National Standards Institute. The standard defines 256 discrete tones. Each tone represents a carrier signal that can be modulated with a digital signal for transmitting data. The specific frequency for a given tone is 4.3125 kHz times the tone number. Tones 1-7 are reserved for voice band and guard band (i.e., tone 1 is the voice band and tones 2-7 are guard bands). Data is not transmitted near the voice band to allow for simultaneous voice and data transmission on a single line. The guard band helps isolate the voice band from the ADSL data bands. Typically, a splitter may be used to isolate any voice band signal from the data tones. Tones 8-32 are used to transmit data upstream (i.e., from the user), and tones 33-256 are used to transmit data downstream (i.e., to the user). Alternatively, all the data tones 8-256 may be used for downstream data, and upstream data present on tones 8-32 would be detected using echo cancellation. Because more tones are used for downstream communication than for upstream communication, the transfer is said to be asymmetric.
Through a training procedure, the modems on both sides of the connection sense and analyze which tones are less affected by impairments in the telephone line. Each tone that is accepted is used to carry information. Accordingly, the maximum capacity is set by the quality of the telephone connection. The maximum data rate defined by the ADSL specification, assuming all tones are used, is about 8 MBPS downstream and about 640 KBPS upstream.
ADSL modems generally employ some mechanism for regulating the power levels to reduce cross talk and non-linear effects from high signal levels. Two mechanisms of regulating power levels are politeness cutback and off-hook cutback. Politeness cutback is generally a cutback applied to prevent overload of an analog-to-digital (A/D) converter of a receiver. The A/D converter of the receiver is likely to be overloaded, for example, when the subscriber loop is short and the attenuation of the line is relatively small. The off-hook cutback is primarily utilized to provide reduction in signal level to remove non-linear elements.
Existing communications systems that employ some form of politeness cutback are generally unreliable, inefficient, and unnecessarily constrictive. Existing communications systems, for example, typically rely on open loop systems to determine politeness cutback, which means that there is no direct communication of power levels. Thus, for instance, a device may measure upstream receiver power to indirectly infer the downstream power required for transmission. This method has several shortcomings. First, such a method requires a priori power level and thereby may be unnecessarily constrictive, and perhaps inefficient. Second, such a method may be unreliable since it employs an indirect approach for determining the required downstream power. This indirect approach is especially prone to inaccuracies in instances where different wires or frequencies are utilized for upstream and downstream communications.
Prior communications systems employing a method to determine off-hook cutback also tend to be unreliable, inefficient, and unnecessarily constrictive. Such systems transmit maximum power, estimate existing distortion levels, and then determine the cutback needed to reduce the distortion to an acceptable level. This method of determining cutback, however, has several shortcomings. First, such a method virtually ensures a strong signal on the line, causing interference to other services, thereby producing the very result the off-hook cutback is intended to avoid. Second, such a method requires a priori power level and therefore may be unnecessarily constrictive, as well as inefficient.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
One aspect of the present invention is seen in a method that includes establishing a pathway from a first transceiver to a second transceiver, determining a power level at the second transceiver, and determining whether the power level at the second transceiver is at an acceptable level over the pathway. The method also includes adjusting a power level at the first transceiver in response to determining whether the power at the second transceiver is at the acceptable level.
Another aspect of the present invention is seen in an apparatus that includes a first and second logic. The first logic is capable of establishing a pathway with a transceiver. The second logic is capable of determining a power level at the transceiver, determining whether the power level at the transceiver is at an acceptable level over the pathway, and adjusting a power level of the apparatus in response to determining whether the power at the transceiver is at the acceptable level.

Method and apparatus employing cutback probe


Upper and lower compartments are provided in metal-clad switchgear that are mirror images of each other. The compartments have doors that move toward one another to lock. The upper compartment has rails at the bottom for receiving a fuse truck, and the lower compartment has a division sheet between the compartment that has openings in it for receiving mating projections on the doors.

1. Field of the Invention
This invention relates to arc resistant metal clad switchgear and particularly to switchgear having upper and lower compartments that are mirror images of one another and arc resistant doors to the compartments. The doors lock against a division sheet between the compartments.
2. Background Information
Metal-clad switchgear design is the first choice design of most consultants and utilities, particularly for medium voltage switchgear operating at voltages of from 5 to 38 KV. Circuit breakers and/or other elements in the switchgear are housed in metal enclosures and are removable. Drawout apparatus are used to move the circuit breakers or other elements between a disconnect position in which the primary contacts are fully disengaged and a connect position in which the primary contacts are fully engaged. The switchgear typically includes a variety of auxiliary devices and related control circuitry, including potential transformers, power transformers and fuse drawer compartments.
The metal-clad design for switchgear concentrates on structure that reduces the possibility of arcing faults within the enclosure. For instance, all primary elements such as breakers, voltage transformers and control power transformers have disconnect means with isolating shutters establishing isolation from the high voltage source.
All operations on breakers, potential transformers and control power transformers, engagement/isolation/test in metal-clad switchgear are preferably performed with the compartment doors closed for operator safety. The front door is interlocked with the shutter assembly to reduce the chance of accidental opening of the front door during even partial levering-in of the breaker/potential transformer/control power transformer drawout element.
The switchgear enclosures containing primary elements have been compartmentalized and grounded for maximum isolation and confinement such as the breaker compartment, main bus compartment and cable compartment. Within these compartments all live parts where possible are fully insulated reducing the possibility of an arcing fault to occur. This need to eliminate or reduce the possibility of an arcing fault has driven the design development to metal-clad switchgear construction for many years.
Although arcing faults are rare, injuries from arcing faults in metal-clad switchgear have continued. When it does occur, the results can be very destructive because of the energy levels reached within a confined compartment. The structural containment may be inadequate to prevent arcing products and hot gases escaping the faulted compartment. Burns can result if operating personnel are in close proximity to the faulted switchgear.
Arcing faults can occur within a switchgear compartment as a result of insulation failure or human error. The pressure from an electric arc is developed from two sources: the expansion of the metal in boiling, and the heating of air by the arc energy. Copper expands by a factor of 67,000 times in vaporizing. This accounts for the expulsion of near-vaporized droplets of molten metal from the arc. One test has shown that droplets could be propelled up to 10 feet. The pressure also generates plasma outward from the arc for distances proportional to the arc energy. One cubic inch of copper vaporizes into 1.44 cubic yards of vapor. The air in the arc stream expands in warming up from its ambient temperature to that of the arc temperature (approximately 35,000.degree. F). All this happens within the first half cycle of the fault and results in a sudden, large rise in pressure inside of the compartment. Switchgear structure is needed to reduce arcing and contain such pressures and to prevent personal injury.
There are several known designs for metal-clad switchgear to allow the doors to withstand the pressure generated from an internal arcing fault, some of which are:
The doors are stiffened, using welded angles and channels and then bolted using many bolts around the perimeter of the door into weld nuts in the cell; PA1 Multi point latch handles that when turned rotate pins or bars into hasps that brace the doors around the perimeter; PA1 A special handle assembly that as the handle rotates the door is either pushed up or down causing mating notches to overlap--this overlapping of the notches gives the door latching system the ability to withstand the pressure; and PA1 A handle that turns a three point latch which extends steel pins into steel pads welded onto one side of the cell in combination with special hinges on the opposite side of the door.
Some medium voltage switchgear include upper and lower switchgear compartments and separate doors for the compartments. An improved switchgear enclosure and door latch system is needed for providing structural containment of pressure that may develop from possible arcing within the switchgear enclosure.
There is need, therefore, in switchgear having an improved latching mechanism for containing pressures that may result if arcing occurs in the switchgear.
There is a more particular need for improved switchgear having upper and lower fuse truck compartments that are mirror images of one another and doors on the compartments that provide improved arc resistance.
There is an additional need for such improved medium voltage switchgear which provides a more efficient and convenient arrangement of compartments and especially for an improved door latch system for the switchgear.


Techniques to integrate a slot antenna with a wireless network card for use with a wireless communication network.

Wireless networks are becoming increasingly prevalent due to the convenience provided to a user. For example, a physical location such as a home or office may include a number of computers, such as a personal computer, laptop computer, handheld computer, and so forth. Such devices are traditionally connected to a network using wired communications media, such as twisted-pair wire or co-axial cable. Wireless networks, however, are currently available that eliminate the need for such wired communications media. An example of a wireless network may comprise an 802.11 network as defined by the Institute of Electrical and Electronics Engineers (IEEE). To arrange a computer for operation with a wireless network, however, may require the use of an antenna. The antenna is typically separate from the PC, thereby introducing additional cables, connectors and space requirements. Consequently, there may be a need for improvements in antenna design for a wireless network.