A power converter includes at least two power conversion sections operating in parallel. The power converter receives a variable input power and generates an AC output voltage. When the power source is generating enough power to supply a DC voltage to the power converter greater than or equal to the peak magnitude of the desired AC voltage output, each power conversion section operates in parallel, converting the DC voltage to the desired AC voltage output. When the power generated by the variable power source results in a DC voltage having a magnitude less than the peak magnitude of the desired AC voltage output, the power conversion sections operate in series. One power conversion section operates as a boost converter to boost the DC voltage level to a suitable level for the second power conversion section, which generates the desired AC output voltage.

The subject matter disclosed herein relates to a method and system for boosting the magnitude of the voltage on the direct current (DC) link of an inverter. More specifically, one inverter section operating in parallel with another inverter section may be selectively configured to either boost the magnitude of the voltage on the DC bus or convert the DC power to alternating current (AC) power.
There is an ever increasing demand for energy supplied by renewable energy sources. The power supplied by many renewable energy sources varies in magnitude and/or frequency. For example, photovoltaic (PV) arrays typically generate DC power which is dependent on the amount of light reaching the array and wind turbines typically generate AC power that varies in frequency according to the velocity of the turbine blades driving the generators. However, electronic devices are designed to be operated by power supplied at a fixed magnitude and frequency, such as the utility grid. Consequently, power converters are utilized with these power sources to convert the variable power supplied by the renewable energy source into power supplied at a fixed magnitude and frequency.
Power converters are available in many configurations. For example, power converters may convert DC to AC, AC to DC, DC at a first voltage level to DC at a second voltage level, or AC at a first frequency to AC at a second frequency. PV arrays typically generate DC power and utilize a power converter to convert the power generated by the array into AC power compatible with a utility grid. Wind turbines typically drive AC generators and utilize a two-stage converter that first converts the variable frequency AC power into DC power and subsequently converts this DC power into AC power compatible with the utility grid. Pulse width modulation (PWM) is one well known technique for converting DC power into AC power compatible with the utility grid.
Pulse width modulation is a high speed switching technique used to convert a DC voltage to an AC output voltage having a desired magnitude and frequency. Over a predefined switching period, the DC voltage is connected to the output for a percentage of the switching period, such that the output voltage alternates between zero volts and the DC voltage. The resulting average DC voltage observed at the output is equal to the magnitude of the switched DC voltage multiplied by the percentage of the switching period during which the reference voltage is connected to the output. The PWM routine may vary this percentage during each switching period such that the average DC voltage at the output changes at a desired AC output frequency. If the switching frequency is much greater than the desired AC output frequency, the voltage observed at the output approximates an AC output voltage.
Because the AC output voltage is generated by PWM switching of the DC reference voltage, the maximum value that the peak AC output voltage may be is equal to the magnitude of the switched DC voltage. Consequently, the DC voltage present in the power converter must be equal to or greater than the peak value of the desired AC output voltage in order for the converter to generate the desired output voltage.
However, due to the variable nature of many renewable energy sources, the DC voltage generated by the energy source is not always greater than the peak value of the desired AC output voltage. For example, the amount of power generated by PV arrays typically follows a bell-shaped curve. During early morning or late evening hours, the amount of power generated by the PV array drops below a minimum power threshold at which the necessary DC voltage to the converter may be maintained. Similarly, wind turbines have a cut-in speed, which is the minimum wind speed at which the wind turbine may operate. If the wind speed drops below this cut-in speed, the amount of power generated by the turbine is again not sufficient to maintain the necessary DC voltage for the converter.
Historically, attempts to overcome this limitation include lowering the magnitude of the desired output voltage. For example, a transformer may be included at the output of the converter. Utilizing the transformer to step-up the output voltage from a lower magnitude to match the magnitude of the grid voltage permits a lower desired output voltage from the power converter and, therefore, the power converter may continue operating at lower DC voltage levels.
However, including a transformer on the output of the converter is not without drawbacks. First, the transformer itself may require a substantial increase in the cost of the system. Second, the renewable energy source generates a specific amount of power, which is the product of the output voltage multiplied by the output current. If the power level remains the same and the output voltage is reduced, the output current necessarily increases. Consequently, the power converter components must be sized to handle the increased current, which similarly increases the cost of the system.
Other attempts to overcome the limitation of a low DC voltage include adding a DC boost converter to the input of the power converter. The DC boost converter increases the DC voltage on the DC link if the voltage level is not of sufficient magnitude to convert the DC voltage to an AC voltage of the desired magnitude. However, adding the DC boost converter requires additional switching devices and their related control components, again increasing the cost of the system.
Thus, it would be desirable to provide a power converter capable of operating over an increased range of DC voltages without a significant increase in cost.

Method and apparatus for boosting DC bus voltage


The present disclosure provides a semiconductor structure. The semiconductor structure includes a semiconductor substrate; and a gate stack disposed on the semiconductor substrate. The gate stack includes a high k dielectric material layer, a capping layer disposed on the high k dielectric material layer, and a metal layer disposed on the capping layer. The capping layer and the high k dielectric material layer have a footing structure.

In advanced technology nodes of integrated circuit industry, high k dielectric material and metal are adopted to form a gate stack of a field-effect transistor (FET) such as a metal-oxide-semiconductor field-effect transistors (MOSFETs). In the existing method to pattern the metal gate stack, due the film uniformity, the work function of a metal layer in the metal gate stack is shifted toward the mid-gap at the gate edge. Accordingly, the threshold voltage is unexpectedly changed, leading to poor short channel control at the constant sub-threshold leakage current. Additionally, the drive current is degraded due to the increase of source drain extension resistance. Furthermore, the poor uniformity of the metal films in the existing method leads to the worsen work function variation within the gate. Therefore, a structure of a metal gate stack and a method making the same are needed to address the issues identified above.

Structure and method for MOSFETS with high-K and metal gate structure

Taiwan Semiconductor Manufacturing Company, Ltd.


Electromechanical devices that generate an electrical signal in response to an external source of mechanical vibrations can operate as a sensor of vibrations and as an energy harvester for converting mechanical vibration to electrical energy. The devices incorporate a magnet that is movable through a gap in a ferromagnetic circuit, wherein a coil is wound around a portion of the ferromagnetic circuit. A flexible coupling is used to attach the magnet to a frame for providing alignment of the magnet as it moves or oscillates through the gap in the ferromagnetic circuit. The motion of the magnet can be constrained to occur within a substantially linear range of magnetostatic force that develops due to the motion of the magnet. The devices can have ferromagnetic circuits with multiple arms, an array of magnets having alternating polarity and, encompass micro-electromechanical (MEM) devices.

As wireless computing and distributed sensor networks become more mature and widespread, a bottleneck for the technology deployment becomes the power source. Conventionally, a wireless, portable sensor or microprocessor is powered by a battery. Though battery technologies have improved, energy densities and lifetimes are still issues for many systems. A battery holds a finite amount of energy; when that energy has been used by its load, the battery must be recharged. For many remote systems, recharging a battery is not an option. If a system is required to remain idle for months or years and then spring to life at a certain moment, a battery may have been depleted already due to leakage or self-discharge. Finally, batteries often involve chemicals which are harmful to humans and to the environment. The present invention provides a solution to these problems in the form of an energy harvesting device for supplying power to (inter alia) small remote systems and conversely as a sensor for sensing vibrations in its environment and generating an electrical signal in response thereto. Applications where harvesting or sensing vibrations can be desired include; air, water and land-based vehicles, oil rigs, heavy machinery, bridges and other architectural structures subjected to vibrations. The terms "vibration sensing device", "vibrational energy converter", "vibrational energy harvester", "energy harvester", and "mechanical vibration to electrical energy converter" are interchangeable in the context of this specification.

Mechanical vibration to electrical energy converter


A method includes inductively coupling an electrical sensor to a transmission line associated with a node of an electrical network, and capturing power transmission information associated with the node through the electrical sensor. The method also includes communicating, through an electrical sensing device including the electrical sensor, information associated with a location of a power outage and/or a sub-optimal performance in the node to a processing node and/or a central control node associated with the electrical network.

When a service interruption occurs, a utility company may deploy resources (e.g., specialized personnel, instruments, etc.) to determine a cause that contributes thereto. The service interruption (e.g., a power outage, a surge, etc.) can create severe risks (e.g., security, financial, hazard, customer satisfaction) that the utility company may wish to avoid. It may take many hours before an accurate location of a contributing factor to the service interruption is determined. As a result, the utility company may be exposed to prolonged risks that adversely affect operations thereof.

Inductive monitoring of a power transmission line of an electrical network


A classifying device having two or more classifying passages is provided, the classifying device including a first classifying passage to which particle dispersion liquid is fed; plural discharge ports provided in the first classifying passage, the plural discharge ports including a discharge port of coarse particle dispersion liquid and a discharge port of fine particle dispersion liquid; a second classifying passage; and a connecting passage that transports the coarse particle dispersion liquid to the second classifying passage, wherein the discharge port of the coarse particle dispersion liquid is provided in more upstream part of the first classifying passage than the discharge port of the fine particle dispersion liquid.

1. Technical Field
The present invention relates to a classifying method and a classifying device.
2. Related Art
A method for classifying fine particles includes a dry method and a wet method. Since a specific gravity difference between a fluid and the fine particle is large in the dry method, the dry method may be highly accurate. In the wet method, the specific gravity difference between a liquid and the fine particle is small, however, since the fine particles are easily dispersed in the liquid, a high classifying accuracy is obtained for a micro power area. The classifying device ordinarily includes a rotor of a rotating part and a stator of a stationary part to classify the fine particles by a balance between a centrifugal force and an inertia force. Further, in the dry method, the classifying device using a "Coanda effect" having no rotating part is merchandized. On the other hand, in recent years, various kinds of methods for carrying out a chemical reaction and a unit operation in a micro area are have been studied and a method and a device have been investigated for efficiently classifying the fine particles without producing impurities.

Classifying method and classifying device


The present application describes a multilayer film having low water vapor permeability. The multilayer film of the present application is readily thermoformed and is, therefore, suitable for blister packaging sheets as well as for food packaging, medical barriers and device packaging, and other general purposes where low water vapor permeability is desired.

Packaging for pharmaceuticals and other medical implements typically employ multilayer films to provide adequate dust and moisture barriers for maintaining the integrity of the items contained within the packages. Conventional films used in these applications contain one or more polymers that are formed from halogenated molecules such as polyvinyl chloride (PVC), polyvinyldiene chloride (PVdC), or fluorinated-chlorinated resins such as poly-chloro-tri-fluoro-ethylene (PCTFE). Although films that incorporate these resins provide effective barriers, manufacturing and disposal of these films can result in undesired effects and sometimes dangerous byproducts. For example, dioxin can be formed from PVC production and disposal, and PVdC can cause excessive corrosion of equipment and packaging machinery.
Producing multilayer films and utilizing such films in a variety of packaging applications is well known. Multilayer films can be produced in a variety of ways and often include extrusion or co-extrusion steps followed by thermal or adhesive lamination, extrusion lamination, and/or extrusion coating. However, some films can be produced solely by co-extrusion.
Co-extrusion of multilayer films is well known in the art and includes co-extrusion blown films and cast films as described, for example, in U.S. Pat. Nos. 3,479,425, 3,797,987, 3,959,431, and 4,406,547. Multilayered films can be produced by co-extruding two or more melt streams through a die to produce a layered structure when allowed to cool. The co-extruded films can further be laminated to other film layers or can be coated with additional polymers to incorporate more layers into a final film product. Since not all polymers readily adhere to each other, some films may also incorporate tie or adhesive-containing layers that facilitate the adhesion of two or more layers in a film. These tie layers can be co-extruded with the other polymeric layers or can be introduced during a lamination process.
Packaging for pharmaceuticals or other moisture-sensitive materials requires not only low moisture permeability but also other properties such as chemical inertness, clarity, rigidity, or uniform thickness. Properties of the finished film such as overall thickness can be controlled by the relative speed and output of the individual extruders delivering the melt streams to the die. In addition, polymer viscosity and melting temperatures of the individual polymers can affect the thickness and adhesion of the layers to each other following extrusion. However, many of the desired finished film properties are unique to each layer within the multilayer film and, therefore, can make co-extrusion of certain films very challenging.
Multilayer films can be shaped into packaging by subjecting them to a thermoforming process. Plastic thermoforming processes are well known in the art and are described, for example, in U.S. Pat. Nos. 4,421,721, 4,994,229, 5,106,567, and 6,086,600. Generally, thermoforming is a process for forming a plastic container or packaging structure by heating a sheet of plastic film to a desired forming temperature and shaping the film by subjecting it to vacuum or pressure shaping in a mold.
Thermoformed blister packaging is often used for commercial packaging of food products, personal care products, and human health products such as pharmaceuticals and medical devices or other implements. The use of this type of packaging has become widespread mainly due to the ability to incorporate suitable moisture, dust, UV and/or gas barriers into the packages when such properties are desired for maintaining the product contained by the package. For example, pharmaceutical blister packaging is effective for maintaining drug tablet integrity. However, the common packaging today typically contains the undesired halogenated polymers described above.
Therefore, there is still a need for multilayer films and thermoformed packaging, especially for pharmaceuticals, that is free of halogenated polymers, is chemically inert and non-corrosive, is aesthetically pleasing enough to present the products contained therein, is durable enough to protect the packaging contents, and is capable of being manufactured on existing equipment in pharmaceutical fill/finish manufacturing plants.


A method of authentication in an IP Multimedia Subsystem (IMS) is provided. After receiving a Register message from a User Equipment (UE), a Proxy-Call Session Control Function (P-CSCF) locates a Connection Location Function (CLF) according to information contained in the Register message and a pre-configured corresponding relationship between the information contained in the Register message and the CLF. The P-CSCF obtains a query result by querying the CLF about attachment information of the UE in an access network, and sends the Register message carrying the query result to an Interrogating-Call Session Control Function (I-CSCF). The I-CSCF forwards the Register message carrying the query result to a Service-Call Session Control Function (S-CSCF). The S-CSCF authenticates the UE according to an authentication mechanism obtained from a User Profile Service Function (UPSF) or a Home Subscriber Server (HSS), and sends an authentication result to the UE.

A Next Generation Network (NGN) as well as a mobile network may generally be divided into an access network and a service network. A user may access an IP network via the access network provided by an access network operator, and then enjoy different services such as voice, video, stream media, etc., through service networks provided by one or multiple service network operators.
When the access network and the service network belong to different operators, authentications of the user in the access network and the service network are independent. In such a scenario, the user needs two types of authentications before enjoying the service. One authentication is in the access layer; after the authentication in the access layer succeeds, the user is able to access to the NGN network. The other authentication is in the service layer; and after the authentication in the service layer succeeds, the user is able to enjoy the services provided by the service network.
When the service network and the access network belong to the same operator, or when there exists cooperation between the access network operator and the service network operator, the service network operator may bind the authentication in the service layer with that in the access layer under some networking scenarios. In other words, the user is regarded to be legal after the authentication in the access layer succeeds, and the authentication in the service layer is no longer required.
In the IMS access layer, an Authentication and Key Agreement (AKA) scheme is usually employed for the authentication of the UE in the IMS service layer.
Referring to FIG. 1, the IMS AKA scheme includes:
Block s101: a User Equipment (UE) sends a Register message to a Proxy-Call Session Control Function (P-CSCF).
Block s102: The P-CSCF, acting as a Session Initial Protocol (SIP) proxy server, forwards the Register message of the UE to an Interrogating-CSCF (I-CSCF).
Block s103: The I-CSCF interacts with a Home Subscriber Server (HSS) through a Cx-Selection-Info message to select a corresponding Service-CSCF (S-CSCF), i.e., the I-CSCF sends a request to the HSS to search a user profile in the HSS to select the S-CSCF for processing the Register message.
Block s104: The I-CSCF forwards the Register message of the UE to the S-CSCF selected in the Block s103.
Block s105: The S-CSCF sends a Cx-Put message to the HSS to update S-CSCF indication information in the HSS and notify the HSS that it has been assigned to serve this user.
Block s106: The S-CSCF sends an AV-Req message to the HSS requesting an authentication vector of the user.
Block s107: The HSS returns an AV-Req-Resp message to the S-CSCF carrying the authentication vector of the user.
Block s108: The S-CSCF determines that the UE needs to be authenticated according to the authentication vector received in Block s107 and the Register message of the UE, then the S-CSCF sends a 4xx Auth_Challenge message containing authentication-relevant information indicating that the UE needs to be authenticated to the I-CSCF. The 4xx denotes a kind of error and the xx stands for a number within 00˜99.
Block s109: The I-CSCF forwards the 4xx Auth_Challenge message to the P-CSCF.
Block s110: The P-CSCF forwards the 4xx Auth_Challenge message to the UE.
Block s111: after receiving the 4xx Auth_Challenge message, the UE sends another Register message to the P-CSCF, at this time, the Register message carries an authentication parameter.
Block s112: The P-CSCF forwards the Register message of the UE to the I-CSCF.
Block s113: after receiving the Register message, the I-CSCF sends a Cx-Query message to the HSS to determine the S-CSCF for processing the Register message, i.e., the I-CSCF queries the HSS about the S-CSCF which has been assigned to serve this user. The HSS returns the S-CSCF name which was previously selected to the I-CSCF according to the S-CSCF indication information stored in the HSS.
Block s114: The I-CSCF forwards the Register message to the S-CSCF determined in the Block s113.
Block s115: The S-CSCF sends a Cx-Put message to the HSS to update the S-CSCF indication information in the HSS and notify the HSS that it has been assigned to serve this user.
Block s116: The S-CSCF downloads a user profile from the HSS through a Cx-Pull message.
Block s117: The S-CSCF authenticates the UE according to the user profile and the authentication parameter in the Register message of the UE. If the authentication succeeds, the S-CSCF sends a 2xx Auth_OK message to the I-CSCF indicating that the registration succeeds, wherein the 2xx indicates that the message is success relevant, and the xx is a number within 00˜99. If the authentication fails, the S-CSCF sends an authentication failure message indicating that the authentication is failed to the I-CSCF.
Block s118: if the authentication succeeds, the I-CSCF forwards the 2xx Auth_OK message to the P-CSCF. If the authentication fails, the I-CSCF forwards the authentication failure message to the P-CSCF.
Block s119: if the authentication succeeds, the P-CSCF forwards the 2xx Auth_OK message to the UE. If the authentication fails, the P-CSCF forwards the authentication failure message to the UE.
France Telecom has put forward a Network Attach Sub System (NASS) Bundled Authentication (NBA) scheme to implement IMS-NASS bundled authentication at the Telecommunications and Internet Converged Services and Protocols for Advanced Networking (TISPAN) #6bis. In the NBA scheme, a Connection Location Function (CLF) in the NASS holds a bundled indication and a corresponding relationship between an IP address of the UE and association information of the UE in the access network. Each connection of the user holds one piece of association information.
Referring to FIG. 2, the NBA scheme includes:
Block s201: The UE sends a Register message to the P-CSCF.
Block s202: The P-CSCF queries the CLF about NASS attachment information of the UE according to a source IP address of the Register message, wherein the NASS attachment information contains the association information of the UE and the bundled indication.
Block s203: The P-CSCF compares the association information and an IP Multimedia Private Identity (IMPI) in an authentication header of the Register message. If the association information is consistent with the IMPI, it means that the authentication in the IMS service layer succeeds, proceed to Block s205; otherwise, it means that the authentication in the IMS service layer is failed, proceed to Block s204 to send a 403 Forbidden to the UE.
Block s205: The P-CSCF forwards the Register message carrying an indicator indicating whether the authentication succeeds to the I-CSCF.
Block s206: The I-CSCF interacts with the HSS through a Cx-Selection-Info message to select a corresponding S-CSCF, i.e., the I-CSCF sends a request to the HSS to search the user profile in the HSS to select the S-CSCF for processing the Register message.
Block s207: The I-CSCF forwards the Register message to the S-CSCF selected in the Block s206.
Block s208: after confirming that the user has successfully registered, without requesting the HSS for the authentication vector of the user, the S-CSCF sends a Cx-Put message to the HSS to update the S-CSCF indication information in the HSS and notify the HSS that it has been assigned to serve this user, and downloads the user profile from the HSS through a Cx-Pull message.
Block s209: The S-CSCF returns a 2xx Auth_OK message to the I-CSCF indicating that the authentication succeeds.
Block s210: The I-CSCF forwards the 2xx Auth_OK message to the P-CSCF.
Block s211: The P-CSCF forwards the 2xx Auth_OK message to the UE.
In the above scheme, the IMPI contained in the Register message is required to be consistent with the association information, i.e., the IMPI in the service layer and the association information in the access layer are the same identity. However, the service network operator is usually not the same with the access network operator. Thus the requirement of using the same identity for the service network operator and the access network operator restricts the flexibility of network applications. Moreover, it is unreasonable that the bundled indication is saved in the NASS. The reasonable method should be that the bundled indication is saved in the service layer (e.g., the HSS), while the access layer is only responsible for providing relevant information. Further, it is also unreasonable for the P-CSCF to implement the authentication. It may be more reasonable that the S-CSCF in a home network implements the authentication in the service layer, and the P-CSCF only provides relevant information of the authentication.
Further, when the state of the user changes, e.g., the user may employ different terminals when in different locations, the authentication adopting the IMS authentication bundled with NASS, which is configured as a default authentication mechanism, will fail. Thus the quality of service is decreased. Therefore, a second authentication mechanism pre-configured in the HSS is required to authenticate the user. However, there are no such solutions in the related art.

This patent is subject to a terminal disclaimer.

Method of authentication in IP multimedia subsystem


A fuel delivery system for removing air from fuel delivered to an engine, and particularly a diesel engine, includes an engine, a primary water separation filter, and a secondary air separation filter. The air separation filter is located downstream from the water separation filter for delivering substantially gas-free fuel to the engine. The air separation filter includes a vessel, a fuel inlet into the vessel, a fuel outlet leading to the engine, a fuel return discharge leading to the fuel tank, and a filter cartridge including filter media presenting numerous small openings therein for permitting the passage of fuel therethrough but screening out bubbles entrapped in the fuel. As the bubbles are trapped on the screen, they float upward to the fuel level and then spill over the upper margin of an upright tube within the vessel leading to the fuel return discharge and then to the fuel tank so that only substantially gas-free fuel is delivered to the engine.

1. Field of the Invention
A novel fuel delivery system for removing entrained air from a source of fuel is provided. The system advantageously includes not only a water separator, but also a separation chamber including filter media for removing air from the fuel.
2. Description of the Prior Art
Internal combustion engines are designed and configured to operate on fuel of a standard quality, and the introduction of impurities into the fuel may impair or prevent operation of the engine. For example, it is well known that even a small quantity of water in diesel fuel may prevent operation of a diesel engine. As a result, most diesel engines in motor vehicles include, in addition to a filter for removing sediment or other solids in the fuel, a water separator for removing water vapor which has condensed in the fuel line or fuel tank, or was introduced into the fuel tank in a liquid state.
Many diesel engines used in over-the-road trucking consume prodigious amounts of fuel. For example, a six cylinder diesel engine operating at full power may utilize 22 to 25 gallons per hour. Fuel is delivered to the cylinder for combustion with the air in precise amounts by fuel injectors. Since the amount of air in the cylinder in a diesel engine is known (determined by the volume of the cylinder), the fuel/air mixture is normally tightly controlled, often by electronic fuel injection which may even compensate for temperature and other variables in the air supply. Unfortunately, when air has been entrained in the diesel fuel and delivered to the cylinder, it has been found that engine performance suffers. The greater the amount of air in the diesel fuel, the more deleterious the effect. Thus, there has developed a need for a fuel delivery system which can remove entrained air and other gases and vapors from the fuel delivered to the engine.


An alignment system aligns a laser beam to a desired position in a reference plane and to a desired direction in the reference plane. The system diffracts the laser light into different diffraction orders that are projected onto a detection plane using different lenses. As the locations of the projections of the different diffraction orders in the detection plane respond differently to changes in position and in direction of the beam in the reference plane, the locations of the projections enable to determine how to adjust the beam so as to get the beam properly aligned. The diffraction and the projection can be implemented by a hologram.

A lithographic apparatus is a machine constructed to apply a desired pattern onto a substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithographic apparatus may for example project a pattern from a patterning device (e.g. a mask) onto a layer of radiation-sensitive material (resist) provided on a substrate.
The wavelength of radiation used by a lithographic apparatus to project a pattern onto a substrate determines the minimum size of features which can be formed on that substrate. A lithographic apparatus which uses extreme ultraviolet (EUV) radiation, being electromagnetic radiation having a wavelength within the range 4-20 nm, may be used to form smaller features on a substrate than a conventional lithographic apparatus (which may for example use electromagnetic radiation with a wavelength of 193 nm).
A lithographic system may comprise one or more radiation sources for producing electromagnetic radiation of the proper wavelength to be used for imaging the pattern on the mask onto a substrate covered with a photosensitive layer. Such a radiation source may involve the use of a high-power laser system to eventually produce the electromagnetic radiation used for the imaging. For example, in order to produce electromagnetic radiation in the EUV range, a high-power CO2-laser may be used to turn a droplet of tin into plasma by stripping the electrons away from the tin atoms, that are left behind as ions. The plasma emits the electromagnetic radiation in the EUV range when the ions and electrons recombine.
In order to get the laser beam from the laser to a point of interest, the lithographic system includes a beam delivery system comprising optical components such as a beam-splitter, a lens or a mirror. It is important that the laser beam is accurately aligned, especially if the laser beam is of high-intensity, in order to prevent damage to the beam delivery system or to hardware beyond and in roder to make efficient use of the laser beam at the pointy of interest, such as the tin droplet. To control alignment of the laser beam, or generally of a beam of electromagnetic radiation, also colloquially referred to herein as a beam of light, one or more of the optical components in the beam delivery system may be manipulated. The manipulation of the beam of light may include alignment of linear components and/or angular components of beam pointing (or beam pointing stability or accuracy) of the beam of light. The linear component of beam pointing may originate from displacement of the beam of light in a direction perpendicular (or substantially perpendicular) to an axis of propagation of the beam of light. The term "linear component" may be indicative of a position of the beam in a reference plane intersected by the beam. The angular component of beam pointing may originate from a tip or tilt of the beam of light relative to some reference axis, i.e., the angular component of the beam may originate from the electromagnetic radiation having a propagation direction different from the direction of the reference axis. The term "angular component" may encompass or be referred to as beam pointing and is indicative of the direction of propagation of the beam of light relative to a reference direction of the reference axis.
Methods for determining the alignment of the beam of light may involve the use of an alignment system that comprises, e.g., one or more beam splitters, mirrors and/or lenses in order to create an image of the beam on a detector such as a camera. The image captured by the camera can then be rendered on a display monitor for inspection by a human operator. However, the use of such an alignment system may require additional space wherein the alignment system is to be installed for operational use. This may make these methods becoming unsuitable for use in a lithographic system, where space may be restricted.
Using such alignment system may lead to information on only one of the linear component and the angular component of the beam as detected by the detector. A user may need to shift or re-orient the beam splitters, mirrors and/or lenses in a path of the beam of light to receive information on either of the linear component or the angular component of the beam of light. This may lead to an increase in the time necessary for alignment of the beam of light in the lithographic system.
It is an object of the present invention to obviate or mitigate at least one problem of prior art techniques.


A process for producing a hydrogenated polymer, which includes a step of hydrogenating aromatic rings of an aromatic vinyl compound—(meth)acrylate copolymer. In the process, the copolymer having a ratio, A/B, of from 0.25 to 4.0 (A is a molar number of constitutional units derived from the (meth)acrylate monomer, and B is a molar number of constitutional units derived from the aromatic vinyl monomer) is hydrogenated in a solvent in the presence of a catalyst which is composed of zirconium oxide supporting palladium. By the process, a highly transparent, hydrogenated polymer is stably and rapidly produced for a long period of time or repeatedly.

1. Field of the Invention
The present invention relates to a process for producing hydrogenated polymers including a step of hydrogenating the aromatic rings of a copolymer of an aromatic vinyl compound and a (meth)acrylate in the presence of a catalyst which is composed of palladium supported on the carrier mainly constituted by zirconium oxide. The hydrogenated polymers obtained by the above process exhibit a high transparency, a low birefringence, a high heat resistance, a high surface hardness, a low water absorption, a low specific gravity, a high transfer property and an excellent mold releasability. Particularly, because of their excellence in the properties required in optical materials, the hydrogenated polymers are used in wide applications such as optical lenses, light guide plates, light diffuser plates, optical disk substrates, and display front panels.
2. Description of the Prior Art
In recent years, amorphous plastics such as acrylic resins, methacrylic resins, styrene-based resins, polycarbonate resins and cyclic polyolefin resins have been used in various applications, in particular, there is an increasing demand for the amorphous plastics in the fields of optical materials such as optical lenses and optical disk substrates because of their excellent optical properties. These optical materials have been required to have not only a high transparency but also a high performance excellent in the balance in a high heat resistance, a low water absorption, mechanical properties, etc.
However, the conventional optical materials do not necessarily satisfy all of these properties and still have problems to be solved. For example, polystyrenes are mechanically brittle, large in the birefringence and poor in the transparency. Although having a good heat resistance, polycarbonates have a large birefringence and a poor transparency nearly equal to that of the polystyrenes. Polymethyl methacrylate has a high transparency, but has a poor dimensional stability due to a very high water absorption and a low heat resistance. Polyvinyl cyclohexane obtained by hydrogenating the aromatic ring of polystyrene exhibits a high transparency, but has a low mechanical strength, a poor heat stability and a poor adhesion to other materials (Japanese Patent 3094555, JP 2004-149549A and JP 2003-138078A). In order to improve the adhesion property, there has been proposed a method of mixing an aromatic ring-hydrogenated product of polystyrene, a double bond/aromatic ring-hydrogenated product of a conjugated diene-styrene copolymer, or a saturated hydrocarbon resin (Japanese Patent 2725402). However, the above method requires a complicated operation. Also, there is disclosed that a hydrogenated product, which is obtained by copolymerizing a vinyl aromatic compound such as styrene with an unsaturated dibasic acid such as maleic anhydride and then hydrogenating 30% or more of the aromatic rings of the resultant copolymer, is improved in the transparency and birefringence as compared with polystyrene (JP 7-94496B). However, the proposed hydrogenated product is still insufficient in the optical properties as compared with acrylic resins.
In addition, copolymers of methyl methacrylate (MMA) and styrene (MS resins) exhibit a high transparency and are well-balanced in the dimensional stability, rigidity and specific gravity, but have a large birefringence.
Aromatic ring-hydrogenated products of MS resins (MSH resins), in particular, MSH resins having an MMA copolymerization rate of 50% or higher, are considerably improved in the birefringence and exhibit a good balance in the transparency, heat resistance and mechanical properties as compared with MS resins.
The hydrogenation of the aromatic rings of aromatic polymers is known in the art (DE 1131885A). It has been recognized in the art that the degree of hydrogenation of the aromatic rings should be increased for a high transparency and the degree of hydrogenation should reach near 100%, otherwise a highly transparent resin cannot be obtained. This is because when the degree of hydrogenation of the aromatic rings is low, the resultant hydrogenated polymers form a block structure to reduce the total light transmittance.
A solid catalyst composed of a carrier such as activated carbon, alumina, silica and diatomaceous earth and a metal such as Pd, Pt, Rh, Ru, Re and Ni supported on the carrier is preferably used because of easiness of separation from the reactants. Although many examples are known about the hydrogenation of not only aromatic polymers but also other polymers such as conjugated diene polymers, it has been difficult to obtain a high degree of hydrogenation and a high reaction rate because of a low reactivity due to the high molecular weight. It is also known that the catalytic activity is easy to be reduced when repeatedly used in the reaction. The reduction in the catalytic activity results in a lowered degree of hydrogenation, to impair the transparency of the resins. To improve the reaction activity, the kind, fine pore structure and particle size of carrier have been examined. For example, there have been reported a method of producing a hydrogenated polystyrene having a degree of aromatic ring-hydrogenation of about 70% by using a catalyst composed of palladium supported on a silica carrier having a particle size of less than 100 μm (Japanese Patent 3094555), and a method of producing a hydrogenated polystyrene by using a catalyst formed by supporting Pt and Rh on a silica carrier having a large pore size of exceeding 600 Å (JP 11-504959A). There is also disclosed a hydrogenation method in which the degree of aromatic ring-hydrogenation is kept low while hydrogenating the ethylenically unsaturated bond in a high degree of hydrogenation in the presence of a catalyst obtained by supporting a group VIII metal on a porous carrier. In the porous carrier, 95% or more of the total pore volume is occupied by pores with a pore size of 450 Å, and the surface area of the supported metal occupies within 75% of the surface area of the carrier (Japanese Patent 320057).
JP 2002-521509A reports that the aromatic rings of polystyrene are completely hydrogenated without decreasing the molecular weight in the presence of a catalyst formed by supporting a group VIII metal on a carrier such as silica and alumina in which the pores having a pore size of 100 to 1000 Å occupy 70 to 25% of the total pore volume, and JP 2002-521508A reports that the aromatic rings of polystyrene are completely hydrogenated without decreasing the molecular weight in an ether linkage-containing hydrocarbon in the presence of a commercially available catalyst for the hydrogenation of low-molecular weight compounds, which is formed by supporting a subgroup VIII metal on a carrier such as silica and alumina in which the pores having a pore size of 100 to 1000 Å occupy less than 15% of the total pore volume of the carrier. JP 1-213306A discloses that a catalyst formed by supporting a metal on an oxide of a group IVa element such as titanium oxide and zirconium oxide exhibits a high catalytic activity even when reused in the hydrogenation of a conjugated diene-based polymer such as NBR. However, this patent document describes only the hydrogenation of a conjugated diene-based polymer and is completely silent about the hydrogenation of the aromatic rings. JP 2000-95815A discloses that the unsaturated bond (inclusive of aromatic ring) of an aromatic-conjugated diene copolymer is efficiently hydrogenated without the elution of the metal components in the presence of a catalyst which is obtained by adding an alkali metal or an alkaline earth metal to a carrier in which the pores with a pore size of 100 to 100000 nm occupy 50 to 100% of the total pore volume of the carrier, and then, supporting a platinum group metal on the carrier so that 90% or more of the metal is present within the surface portion of the carrier (depth within 1/10 of the pore diameter).
JP 2003-529646A reports that the catalyst activity can be improved by conducting the hydrogenation after removing catalyst poisons from a polymerization product solution by an activated alumina, and JP 2002-249515A reports that the productivity can be increased by improving the linear reaction rate in a fixed bed reaction.
The hydrogenation of aromatic rings is largely affected by the solvent used because it is a polymer reaction. In the known hydrogenation methods, various reaction solvents such as hydrocarbons, alcohols, ethers and esters are used (JP 2001-527095A). However, hydrocarbons and alcohols are poor solvents for the resins. Ethers such as 1,4-dioxane have a low ignition point and the solvent should be replaced with another solvent such as toluene before the volatilizing extrusion at a high temperature. Further, tetrahydrofuran as the ether solvent is unstable because readily undergoes a ring opening reaction. Esters are safe and relatively stable, and allow the hydrogenation to proceed rapidly. However, esters make the obtained reaction solution and solid resin cloudy, to reduce the transparency. To solve this problem, there has been proposed a method in which a highly transparent hydrogenated aromatic polymer is safely, stably and rapidly produced by conducting the hydrogenation in a mixed solvent of an ether and an alcohol. However, the separation of two kinds of solvents makes the process complicated. Japanese Patent 2890748 discloses that a high transparency can be achieved even at a low degree of hydrogenation by using a mixed solvent of an ether solvent with an alcohol or water. However, the proposed method is not applicable to many polymers because it is effective for only limited aromatic polymers.
As described above, the conventional production of aromatic ring-hydrogenated polymers having high optical properties involves various difficulties and problems. In particular, although the hydrogenated polymers obtained by hydrogenating the aromatic rings of a copolymer of an aromatic vinyl compound and a (meth)acrylate exhibit excellent properties such as a high transparency, low birefringence, high heat resistance, high surface hardness, low water absorption and low specific gravity, no method suitable for stably and rapidly producing such polymers repeatedly or for a long period of time has been provided until now.

Process for producing hydrogenated polymers


A method and an apparatus are provided for impedance matching using an analog circuit. The method comprises providing the analog circuit to substantially match a start impedance to an end impedance and tuning a performance parameter of an associated circuit using the analog circuit operating at a high power level. The analog circuit may transform the start impedance to the end impedance using a characteristic impedance in a range above the start impedance and the end impedance. By reconfiguring the analog circuit, the associated circuit may operate at one of a first, second, or higher order frequency bands. By using a matching transformation process, reconfigurable matching circuits for medium and/or high power applications may be provided by using available lower power reconfiguration elements. In the matching transformation process, the intermediate impedance at which the reconfiguration is performed is higher than the matching processes used for lower power reconfiguration elements. A relatively smaller and cheaper reconfiguration element having lower parasitics may be used.

1. Field of the Invention
This invention relates generally to telecommunications, and more particularly, to wireless communications.
2. Description of the Related Art
Communications systems typically comprise software and hardware, including a variety of analog and digital electronic circuits. To improve performance of communication systems, old circuit designs are routinely replaced with new designs that meet specifications for more advanced products. However, one constant goal is to reduce costs of the circuits to be competitive in the market. Therefore, the product circuit designers are generally searching for creative ways to reduce the cost of the electronic circuitry and systems. One means to reduce the costs is to use only one type of analog hardware. For example, in reconfigurable or tunable circuits, one type of reconfigurable matching circuits has been routinely used to serve different frequency bands. A reconfigurable matching circuit may optimize the performance of an analog circuit to the instantaneous operating frequency band. This "one hardware" approach leads inherently to a reduction in cost for the hardware due to higher volume, less design risk and design time and less liability.
To implement reconfigurable matching circuits, continuous variable components like varactors, variometers and potentiometers and/or switching components like relays, switches and PIN-diodes are usually deployed. One problem with continuous variable components or elements is that they have relatively low maximum ratings for power and current, which generally limits their use to low-power stages. As a result, reconfigurable elements for higher power and current are not readily available. One type a reconfigurable element that may be used with higher power and current is bulky, expensive and cannot be integrated into an analog circuit because they lack a form and fit equivalent to other surrounding circuits.
A matching process generally involves a start impedance, for example, the low output impedance of a RF power amplifier, which is to be transformed to an end impedance, for example, a commonly used 50 Ohm system. Matching of the impedance may be achieved by using one or more matching reconfiguration elements with characteristic impedances that lie between the start and the end impedance. One particular disadvantage of such reconfigurable elements is their low maximum rating for power and current, which limits use of this matching to low-power stages. In other words, this matching process may not be optimized to the extent desired for reducing the current and/or DC-dissipation load of the matching reconfigurable components. Thus, for medium or high power applications, the traditional design approach, that results in, with a single dedicated hardware for a particular dedicated frequency band, is still valid.
For example, growth of wireless communication systems has increased the demand for highly efficient analog circuits, such as power amplifiers including radio frequency (RF) power amplifiers. A power amplifier is an active, two-port device that exhibits both linear and non-linear behavior. Some design parameters for RF power amplifiers include high output power, high linearity, and good efficiency.
Moreover, newer technologies demand transmission of large amounts of data with only a small portion of the spectrum being used. This may be accomplished using sophisticated modulation techniques, leading to wide, dynamic signals that benefit from linear amplification. For instance, some modern wireless applications, such as those based on the Wideband Code Division Multiple Access (WCDMA) standard, use non-constant envelope modulation techniques with a high peak-to-average ratio. In many modern mobile communication networks, however, the transmission gets more and more complex using higher power levels.

Reconfiguring impedance matching for high power circuits


According to one embodiment, an electronic device includes a housing including a shield region, and a non-shield region formed of a dielectric, a part of the shield region is formed of a conductor, an antenna in the non-shield region, a vibration generating member including a casing formed of a dielectric, the vibration generating member being in the housing such that a surface of a part of the casing in the shield region and another part of the casing in the non-shield region, and an elastic support member which is sandwiched between the housing and the part of the casing, the elastic support member having a conductive property.

Several types of electronic devices such as notebook PC or mobile PC comprise telecommunication functions. As antennas for communication mounted on the electronic devices, for example, antennas for wireless LAN, antennas for Long Term Evolution (LTE), and antennas for the fifth generation mobile communication system (5G) are known. When the antenna is mounted on a housing together with a circuit board and the like, the performance of the antenna needs to be secured in consideration of the influence of the noise produced by electronic components such as CPU.


A multi-head tandem printer is disclosed which includes an optical encoder or other device mounted on a roller (the xe2x80x9cencoder rollerxe2x80x9d) in contact with the print media. The device and encoder roller serve as a tachometer to measure the media transport speed (referred to herein as the xe2x80x9cprint speedxe2x80x9d). The print heads are arranged so that the unloaded receiver length between two print heads is an integral multiple of the unloaded receiver length transported for each revolution of the encoder roller. In one embodiment, the print heads are arranged so that the inter-head spacing is an integer multiple of the circumference of the encoder roll. Adjustments may be made to the inter-head spacing to take into account factors such as the thickness of the receiver and the curvature at the line of receiver contact with the encoder roll. Such techniques may be employed to reduce the effect of mechanical errors on color registration.

This application is related to copending, commonly-assigned U.S. patent application Ser. No. 10/080,883, filed on Feb. 22, 2002, entitled xe2x80x9cA High-Speed Photo-Printing Apparatus,xe2x80x9d which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to reducing registration errors in tandem printers and, more particularly, to reducing registration errors in tandem printers by equalizing roller diameter and print head spacing.
2. Related Art
Conventional color thermal printers typically include multiple thermal print heads, each of which is responsible for printing a distinct color. In a four-head printer, for example, the four print heads may be responsible for printing cyan, magenta, yellow, and black, respectively. The print heads are typically spaced some distance apart from each other in a row or other configuration.
The medium on which output is to be printed (referred to as the xe2x80x9coutput medium,xe2x80x9d xe2x80x9cweb,xe2x80x9d or xe2x80x9creceiverxe2x80x9d) is typically provided on a continuous roll, referred to as the xe2x80x9creceiver roll.xe2x80x9d The receiver is pulled from the receiver roll through the printer by a drive capstan roller located after the final print head. In this manner the receiver passes by and makes contact with each print head in succession. Each print head transfers pigment of a corresponding color from a donor element to the receiver as the receiver passes by it. In this way, a four color image may be printed by successively printing each of four single-color layers on the output medium. The processes of printing distinct colors of an image at successive print stations is referred to as xe2x80x9ctandem printing.xe2x80x9d
Printing a single four-color image in this manner requires that the image layers be in precise registration (alignment) with each other. The xe2x80x9cregistrationxe2x80x9d of multiple layers (and of individual dots within them) refers to the relative position between the layers. Ideally, all layers in an image are superimposed exactly on (i.e., precisely registered with) each other. Even a slight misregistration may cause noticeable visual artifacts, thereby detracting from the perceived quality of the resulting image.
Misregistration may be caused by any of a variety of factors. For example, although in an ideal printer the receiver moves through the printer at a constant speed, in practice the speed of the receiver may vary. Such variations in speed, if not properly taken into account, may cause a particular print head to print some or all of an image at the wrong location on the receiver, causing misregistration and other problems. For example, variation in the speed of the receiver while a print head is printing may cause the image layer being printed either to be compressed (if the receiver slows down) or stretched (if the receiver speeds up) on the receiver. Although such a distortion may not be objectionable in an image printed by a single print head, multiple such distortions superimposed on each other by multiple print heads can cause problems such as objectionable color variations in what should be areas of uniform color.
Various attempts have been made to ensure proper registration among the various layers of an output image by correcting for variations in receiver speed. For example, in at least one system registration marks have been printed along the lateral edges of the output medium. Optical sensors positioned at each print head have read the registration marks to enable the printer to continuously recalculate the correct printing position for each layer of the image to be printed, thereby allowing the printer to compensate for shifting and stretching of the image on the output medium that may occur at or between each print head. In at least one other system, an integral relationship has been established between the circumference of two output capstan drive rollers and the distance between successive print heads.
Although these approaches may provide some improvement over systems which do not include any corrections for speed variation, they may fail to measure variations in web speed with the accuracy required. The capstan drive roller, for example, may not provide a perfect measurement of web speed because it can slip as the back tension on the web varies.
What is needed, therefore, are improved techniques for correcting for registration errors in tandem printers.
A multi-head tandem printer is disclosed which includes an optical encoder or other device mounted on a roller (the xe2x80x9cencoder rollerxe2x80x9d) in contact with the print media. The device and encoder roller serve as a tachometer to measure the media transport speed (referred to herein as the xe2x80x9cprint speedxe2x80x9d). The print heads are arranged so that the unloaded receiver length between two print heads is an integral multiple of the unloaded receiver length transported for each revolution of the encoder roller. In one embodiment, the print heads are arranged so that the inter-head spacing is an integer multiple of the circumference of the encoder roller. Adjustments may be made to the inter-head spacing to take into account factors such as the thickness of the receiver and the curvature at the line of receiver contact with the encoder roller. Such techniques may be employed to reduce the effect of mechanical errors on color registration.
In one aspect, for example, the present invention features a printing apparatus comprising a plurality of print heads, means for feeding a receiver past each of the plurality of print heads, and an encoder roller, wherein the unloaded receiver length between at least two of the plurality of print heads is an integral multiple of the unloaded receiver length transported between the at least two print heads for each revolution of the encoder roller.
The unloaded receiver length between each successive print head may be an integral multiple of the unloaded receiver length transported between the at least two print heads for each revolution of the encoder roller.
In particular, the distance between at least two of the plurality of print heads may be an integral multiple of the circumference of the encoder roller. The distance between each successive print head, for example, may be an integral multiple of the circumference of the encoder roller.
The encoder roller may be located prior to the plurality of print heads in the path of the receiver. The printing apparatus may further include print speed measuring means for measuring an instantaneous print speed of the printing apparatus, the print speed measuring means including the encoder roller and an encoder mounted to the encoder roller.
The printing apparatus may further include means for receiving output from the print speed measuring means, and means for adjusting an output timing of an least one of the plurality of print heads based on the output received from the print speed measuring means.
Other features and advantages of various aspects and embodiments of the present invention will become apparent from the following description and from the claims.

Registration error reduction in a tandem printer


The present invention relates to an automatic unbuckling seat belt system adapted to easily buckle and unbuckle the seat belt, wherein the system comprises a seat belt tongue formed with a groove and a seat belt buckle with a latch for suspending in the groove and maintaining the coupled state with the seat belt tongue. An ignition key detecting switch detects whether the ignition key is inserted. An Electronic Control Unit (ECU) controls the latch of the seat belt buckle to be removed from the groove of the seat belt tongue if the ignition key detecting switch detects that the ignition key is taken out. A first relay provides power by being activated according to the control of the ECU. A first electromagnet generates the magnetic force via the power provided through the first relay and pulls the latch from the groove.

In general, a vehicle's seat belt is designed to protect the driver during a vehicle collision or the like to prevent injury. The seat belt, constructed with two or three supporting points, typically supports a driver's abdominal region and the chest. The buckling and unbuckling operation of the seat belt is normally manually performed. Therefore, there is a drawback in the conventional seat belt system in that the manual manipulation of the seat belt is inconvenient in emergency situations such as when escaping from the vehicle in the event of a vehicle collision or the like.