There is provided a hard-material-coated member which is suitable as a long-life mold for plastic working of metals and which has a metal as base material and coating layers formed at least on its working plane by physical vapor deposition. At least three layers, i.e., a layer a) as the outermost layer, a layer c) just above the base material and a layer b) between layer a) and the layer c) are formed as coating layers. The hardness values of these layers in terms of hardness symbol HV 0.025 are as follows:                2500>(the hardness of the layer a)>1000,        3500>(the hardness of the layer b)>2300,        2500>(the hardness of the layer c)>1000,        (500+the hardness of the layer a)<(the hardness of the layer b), and

The present invention relates to a hard-material-coated member excellent in durability which is the most suitable as, for example,
(1) a mold for plastic working which is used for forging, pressing or the like and is required to have wear resistance, and
(2) a casting member used in contact with a molten metal, such as a mold used for die casting or casting, a core pin, a piston ring used in an injection machine for die casting, or the like.
Molds obtained by using a metal or steel, such as cold-die steel, hot-die steel, high-speed steel, a hard alloy or the like as a base material have been used for plastic working such as forging or pressing. Methods for the above working are classified into cold working in which working is conducted near room temperature and warm or hot working (hereinafter referred to also as warm-hot working) in which a material to be processed is heated at 400° C. or higher. A mold used in either of these working methods is required to have wear resistance on its working plane.
In recent years, a load on the surface of a mold has been increased with an increase in the strength of a material to be processed, an increase in the precision of a product and an increase of the speed of a molding cycle. Therefore, molds having a working plane coated with a hard material such as TiC or TiN by chemical vapor deposition (hereinafter referred to also as a CVD method) have increased in number. However, as characteristics required of a mold, not only wear resistance but also increased precision of the mold itself has come to be required. Therefore, a CVD method employing a coating temperature of 1,000° C. or higher has become unable to satisfy the above-mentioned requirement sufficiently because the mold is remarkably deformed during the coating and a steel-based mold material involves a problem of heat-treatment distortion caused by heat treatment such as quenching and tempering conducted after the coating.
In such circumstances, physical vapor deposition (hereinafter referred to also as a PVD method) has come to be often adopted which permits coating at a temperature lower than a tempering temperature for a mold material. For example, in the case of cold working, there have been proposed a method in which a base material for a mold in a specific composition range is subjected to a nitriding treatment and then a coating layer of TiN is formed by a PVD method (patent document 1) and a method in which the surface of a mold is coated with a nitride, carbide or carbonitride composed mainly of V, by a PVD method (patent document 2). In the case of hot working, there have been proposed a method in which a pretreatment for a PVD method is specified and coating with CrN or TiAlN is conducted after a nitriding treatment (patent documents 3 and 4) and a method in which a CrAlWN coating film containing Al and W is formed (patent document 5).
On the other hand, steels such as hot-die steel, high-speed steel, stainless steel and the like have been used in casting members used for molding by casting of a molten metal. A metal to be molded that is most frequently used for molding by casting is an aluminum alloy. In the case of the above-mentioned steel materials used in casting members such as molds, the steel material in a portion of the casting member in contact with the aluminum alloy is wasted by melting in a melt of the aluminum alloy to increase the iron content of the aluminum alloy melt and deteriorate the quality of a cast product. Moreover, the waste by melting of the molds and the like causes various operational troubles.
As a measure against the above problem, nitriding on the working plane of a casting member has been often conducted because it gives a deep hardened layer and can be conducted at a very low cost. However, since employment of a high-melting aluminum alloy as a material to be molded has become frequent for the purpose of increasing the strength of a cast product, nitriding has the following disadvantages: N in the hardened layer is easily diffused into an aluminum melt at a high temperature, so that the resistance to the waste by melting is deteriorated by the disappearance of the hardened layer, resulting in rapid progress of the waste-by-melting phenomenon.
In order to solve such a problem, employment of a mold having a working plane coated with a ceramic hardly reactive with a molten metal by physical vapor deposition (hereinafter referred to also as a PVD method) has become frequent. There have been proposed, for example, a method in which a base material for a mold is subjected to carburizing or nitriding and then a coating layer of TiC, TiN or the like is formed by a PVD method (patent document 6), and a method in which the surface of a mold is coated with a Ti intermediate layer and then TiAlN (patent document 7). There have also been proposed methods in which CrN is used as a coating layer (patent documents 8 and 9).
Patent document 1: JP-A-58-031066
Patent document 2: JP-A-2002-371352
Patent document 3: JP-A-11-092909
Patent document 4: JP-A-2003-245738
Patent document 5: JP-A-2005-008920
Patent document 6: JP-A-61-033734
Patent document 7: JP-A-07-112266
Patent document 8: JP-A-10-137915
Patent document 9: JP-A-2001-011599
As to a mold for plastic working, a coating layer of TiC or TiN formed by a CVD method has a high hardness and a relatively large thickness of about 10 μm and hence has satisfactory characteristics, but the precision of a mold having such a coating layer is not satisfactory because of, for example, the deformation of the mold caused by a high coating temperature. On the other hand, the coating layer formed by a PVD method, which has been proposed in any of patent documents 1 to 5, gives a satisfactory precision to a mold but is inferior in adhesion to a layer formed by a CVD method. Therefore, when an attempt is made to impart a sufficient durability to the mold by increasing the layer thickness, the coating layer becomes easily peelable. Accordingly, the function of the coating layer cannot sufficiently satisfy the requirements in the use environment of molds for forging or pressing which has become severe year by year.
As to a casting member, an aluminum alloy melt is cast at a relatively high temperature because of a recent increased speed of casting cycles. Therefore, the use environment of a member used in contact with the melt, such as a casting mold, has become more severe. That is, the following troubles have come to be remarkably caused: the thermal expansion of a mold or other members by a molten metal during casting; and the deflection of the mold or the members by shrinkage thereof by application of a mold release agent after the solidification of a material to be processed or by the solidification and shrinkage of the material to be processed. As a result, the coating layers having the compositions proposed in patent documents 6 to 9 are peeled off during use of a member having the coating layer, and a molten metal infiltrates into the member through the peeled portion and reacts with iron in a base material just under the surface treatment layer of the member to form an alloy. When a portion just under the surface coating layer is expanded by the formation of the alloy, the following phenomenon is observed: the treatment layer is peeled off in a moment, so that the waste of the member by melting proceeds rapidly.
In recent years, die cast products of aluminum alloys or magnesium alloys have come to be used as the boxes of hard discs, personal computers, mobile phones and the like, which are required to be reduced in weight. Therefore, such cast products have been reduced in thickness. In order to reduce the thickness of the cast products, the speed of injection of a melt into a mold has to be increased. The above proposed coating layers have insufficient resistance to wear by a melt. An explanation is given below by taking the case of a casting mold. Since the coating layer is worn away by a fluid in a region near the gate of the mold where a melt is introduced into the mold at a high speed, the mold repairing cycle and the mold life are decreased, and the shape of a cast product is unsatisfactory.
The present invention is intended to provide a hard-material-coated member that is excellent in durability because of the excellent adhesion of its coating film in various use environments. Specifically, the present invention is intended to provide a hard-material-coated member which is the most suitable as a mold for plastic working which is used for plastic working of a metal, such as cold or warm-hot forging or pressing and is free from the above problems involved in a mold required to have wear resistance. Furthermore, the present invention is intended to provide a hard-material-coated member which is the most suitable as a casting member free from the above problems which is used with its working plane being in contact with a molten metal at a high temperature, such as a die casting mold or a core pin.

Hard-material-coated member excellent in durability

Abstract: (500+the hardness of the layer c)<(the hardness of the layer b); the thickness of the layer b) is smaller than that of the layer c); and the total thickness of the coating layers is 5 to 15 μm.


A detachable toe strap and ankle strap mounting arrangement for a simple shoe, the arrangement includes at least one pairs of locating members, each locating member having a plug hole and a serrated constraint tongue in the plug hole, at least one pair of mounting strips detachably connected to the locating members, each mounting strip having a transverse insertion slot at the top, and at least one downwardly extended, serrated plug strip at the bottom for plugging into the plug hole on one locating member for engagement with the corresponding serrated constraint tongue, and at least one strap fastened to the at least one pair of mounting strips for securing at least one part of the user's foot to the sole of the shoe, each strap having two ends respectively inserted through the insertion slots on one pair of mounting strips and fixedly secured thereto by stitches, and a pin kept in a hole thereon, the pin being used for insertion into the plug hole on one locating member to disengage the respective serrated plug strip from the respective serrated constraint tongue.

The present invention relates to a detachable toe strap and ankle strap mounting arrangement for a simple shoe, and more particularly to such an arrangement which enables the user to set the shoe into a sandal or a slipper.
A regular slipper is generally comprised of a sole, and a toe strap fastened to the sole. When making a sandal, an additional ankle strap is added to the sole. Conventionally, the toe strap and the ankle strap are fastened to the sole by stitches. This stitching operation must be operated by skilled persons. Further, the stitches wear out quickly with use, and the protruded portions of the stitches make the user feel uncomfortable. In recent years, press sealing techniques have been intensively used to fasten a toe strap or ankle strap to a sole. According to these techniques, insertion holes made on the sole, then the ends of the toe strap or ankle strap are respectively inserted into the insertion holes, and the ends of the toe strap or ankle strap are sealed to the sole by a press. However, this mounting process is still complicated. Furthermore, when a toe strap and an ankle strap are fastened to a sole to form a sandal, the ankle strap cannot be detached from the sole to change the sandal into a slipper.

Detachable toe strap and ankle strap mounting arrangement for a simple shoe


This invention relates to a vacuum processing method and apparatus. When a sample is plasma-processed under a reduced pressure, a sample bed is cooled by a cooling medium kept at a predetermined temperature lower than an etching temperature, the sample is held on the sample bed, a heat transfer gas is supplied between the back of the sample and the sample installation surface of the sample bed, and the pressure of the heat transfer gas is controlled so as to bring the sample to a predetermined processing temperature. In this way, a sample temperature can be regulated rapidly without increasing the scale of the apparatus.

1. Field of the Invention
This invention relates to a method and apparatus for vacuum processing. More particularly, the present invention relates to a method and apparatus for vacuum processing which is suitable for controlling a sample such as a semiconductor device substrate to different temperatures and vacuum processing the sample.
2. Description of the Prior Art
As disclosed in, for example, Japanese Patent Laid-Open No. 76876/1984, a conventional technology for vacuum-processing a sample by controlling it to different temperatures is such that an object (hereinafter referred to as a "substrate") to be etched is placed on an electrode disposed in a vacuum vessel, a reactive gas is introduced into the vacuum vessel, a voltage is applied to the electrode so as to generate gas discharge and the substrate is etched by this discharge gas at two or more different electrode temperatures.
In the prior art technology described above, a substrate temperature (to 60.degree. C. in this prior art technology) is raised in view of the etching selection ratio of MoSi.sub.2 to a resist and of producibility when an MoSi.sub.2 film is etched, and the substrate temperature (to 30.degree. C. in this prior art technology) is lowered in view of over-etching. This prior art technology in the electrode is divided into an electrode on a high temperature side and another on a low temperature side. Etching of the substrate is carried out on the higher temperature electrode side, and after this etching, the substrate is transferred to the lower temperature electrode, and over-etching of the substrate is carried out. Alternatively, only one electrode is provided and the electrode temperature can be changed to high and low temperatures while the substrate is kept placed on the same electrode. The substrate temperature is raised to a high temperature to conduct its etching during processing and is lowered to achieve overetching of the substrate after the etching.


A portable system for stunning an animal is provided that includes a hood into which the animal's head is inserted and then is filled with a gas, such as carbon dioxide. The hood includes a gasket or covering with a slit on one end, which allows the hood to be placed over the head of the animal by a user while containing much of the carbon dioxide gas. The hood includes a handle and may have a trigger or other mechanism to control the flow of carbon dioxide gas, which is contained in a tank strapped to a user and connected to the hood via a hose or tubing. In this way, the system allows animals to be humanely stunned or euthanized individually with carbon dioxide gas using a portable system that is carried and controlled by an individual user.

There are many techniques for euthanizing animals, including domesticated animals, other livestock, and pests. Some of these techniques include the use of a gas, such as carbon dioxide, to cause the animals to become unconscious and/or euthanized. This is typically accomplished by placing a group of animals into a large chamber and filling it with carbon dioxide gas. There is a need for an improved technique that uses a gas.

Portable controlled atmospheric stunning device


A method and a semiconductor device are provided. The semiconductor device includes a partial via etched in a stacked structure and a trough above the partial via. The method includes performing thick wiring using selective etching while etching the partial via to an etch stop layer.

1. Field of the Invention
The invention generally relates to a semiconductor device and method of manufacture and, more particularly, to a semiconductor device having analog, or super thick, wires and a method of manufacturing thereof using a dual-damascene process.
2. Background Description
Super thick damascene copper (Cu) wires (e.g., >2 um thick) are currently fabricated with single damascene processing. The use of a single damascene process is mainly due to integration problems associated with dual-damascene processing, including the problem of contacting both MIM capacitors and underlying wiring layers during the via and wire etching processes.
In the super thick dual-damascene Cu wire processes, the vias and trenches are defined using conventional lithography steps. In these conventional processes, the via is about 5.5. μm in height and at about 1.5 μm in width. After the formation of the via, the via is filled with spin on organic material such as, for example, anti-reflective coating (ARC), to the underlying Cu wiring layer Mx, for a trough lithographic step.
However, it has been found that the second dual-damascene lithography step is difficult to make work in the super thick damascene Cu wire processes. By way of example, for a via first, trench last process, it has been found that the ARC forms an hourglass formation in the via which, in turn, results in large voids in the via. More specifically, it has been found that none of the industry standard mid UV (MUV) or Deep UV (DUV) ARCs achieved more than 40% fill, with all of them leaving large voids in the vias which opened up during trough etch. And, due to these voids, subsequent etching caused corrosion in an underlying metal layer due to the etchant etching through the voids.
If the ARC, for example, is made thicker, there is better fill properties within the via; however, other problems arise during the subsequent etching process. For example, acceptable via fill can be achieved using an 0.8 um layer, but this severely complicates the trough RIE due to the very long ARC open step required, and due to large fences or rails generated around the vias during trough RIE. More specifically, during the RIE process using the thicker ARC fill, fences are formed on the sides of the via, early in the trough RIE process. This leads to preferential etching along the via edges down to an underlying metal (Mx) layer. Thus, it was found that when the ARC is of about 0.8 um, there is resist erosion, massive fencing and trough RIE (reactive ion etching) problems.
The invention is directed to overcoming one or more of the problems as set forth above.

Dual-damascene process to fabricate thick wire structure


An apparatus for removing an outer layer from a portion of a multi layer tube is disclosed. The apparatus includes a support assembly which holds the portion of the tube at a preset position. A nozzle is fluidly connected to a source of high pressure water and has its outlet directed towards the portion of the tube. A relative, rotary motion about a concentric axis between the nozzle and the tube directs the water such that it removes the outer layer from the tube portion around the entire circumfery of the tube. In one embodiment, the nozzle is held stationary while the tube portion is rotated relative to the nozzle while in a second embodiment the tube portion is held stationary while the nozzle is rotated relative to the tube portion. The apparatus is particularly useful for removing an outer nylon covering from a metal tube.

I. Field of the Invention
The present invention relates to a device for removing an outer layer from a portion of a multi layer tube.
II. Description of the Prior Art
Multi layer tubes are used in a multiplicity of different applications including the auto industry. For example, such multi layer tubing is used for the brake tube assembly for automotive vehicles.
The brake tube assembly for automotive vehicles typically comprises a multi layer construction in which the innermost layer consists of a metal tube, typically made of copper coated low carbon steel. The metal tube is rolled from flat stock into a tube and brazed together in order to form the inner metal tube.
In order to protect the inner metal tube from corrosion, a corrosion resistant coating, typically made of zinc-based alloy, is provided around the entire circumfery of the inner metal tube. An outer protective sleeve, typically constructed of nylon, is then applied over the corrosion resistant coating to protect the corrosion resistant coating, and thus the inner metal tube, from abrasion and other mechanical impact. Consequently, the entire brake tube assembly comprises a three layer construction having an inner metal tube, a middle corrosion resistant coating and an outer nylon sleeve.
In order to attach a metal end connector, such as a brake tube nut, to the brake tube assembly, it is necessary to first remove the outer nylon sleeve from the end portion of the brake tube assembly. However, since the nylon exhibits substantial adherence to the corrosion resistant coating, it has been previously difficult to achieve both rapid and complete removal of the nylon from the end portion of the brake tube assembly. The inability to rapidly remove the nylon from the end portion of the brake tube assembly increases the overall manufacturing cost while the failure to completely remove the nylon from the end portion of the brake tube assembly can result in an inadequate and unacceptable seal between the end connector and the end portion of the brake tube assembly.

Apparatus for removing an outer layer from a portion of a multi layer tube


One or more X10 gateway components of an apparatus in one example communicate one or more messages between one or more mobile communication devices and one or more module components.

People desire to automate a home, apartment, or office using X10 technology offered by X10 Wireless Technology, Inc. (Seattle, Wash., www.x10.com). X10 technology employs a signaling language to control one or more electrical devices through one or more electrical lines of the home, apartment, or office. One example of X10 technology is an X10 gateway component. A user employs the X10 gateway component and one or more module components to automate and/or monitor the home, apartment, or office. In one example, the user sends one or more messages to the X10 gateway component to control the electrical devices through employment of the module components. In another example, the user receives one or more messages from the X10 gateway component. For example, the user employs the messages to monitor the electrical devices at the home, apartment, or office.
The user in one example desires to communicate the messages between the X10 gateway component and the communication device from a remote location. The communication device connects to a processing center. Upon connection to the processing center, the user gives an employee of the processing center one or more messages to control the electrical devices in the home, apartment, or office. The employee sends the messages through the internet to a landline modem coupled to the X10 gateway component. The X10 gateway component obtains the messages from the landline modem to control the electrical devices.
As one shortcoming, the user can only communicate with the X10 gateway component through the processing center. For example, the user may want to communicate directly with the X10 gateway component. As another shortcoming, the X10 gateway component cannot communicate with the user of the communication device through a mobile network or a broadband internet connection.
Thus, a need exists for an X10 gateway component that communicates messages with a communication device without an intermediate processing center. A further need exists for the X10 gateway component to communicate messages with the communication device through a non-landline internet connection.

X10 communication of one or more messages between one or more mobile communication devices and one or more module components


A direct-writing electron beam is used for defining features in a resist layer and hence ultimately in an underlying workpiece, such as in a phase-shifting mask substrate or a semiconductor integrated circuit wafer. The resist layer is located on a top major surface of the workpiece.. In a specific embodiment, the resist layer is located underneath a protective layer of polyvinyl alcohol ("PVA"); and a grounded conductive layer, such as a conductive organic layer, is located on the protective layer. After exposing the top major surface of the resulting structure to the direct-writing electron beam, the following steps are performed:. (1) a plasma etching completely removes the entire thickness of the conductive layer as well as a small fraction of the thickness of the PVA layer; PA0 (2) the PVA layer is then completely removed by dissolving it in water; PA0 (3) another plasma etching removes a small fraction of the thickness of the resist layer, including any unwanted residues; and PA0 (4) the resist layer is developed.

Charged beam lithography involves bombarding a resist layer with a scanning charged beam whose intensity varies with time (i.e., a spatially selective scanning beam having a prescribed resulting lateral pattern). The charged beam is typically an electron beam (a "direct-writing electron beam"). The resist layer is located on a workpiece. The workpiece typically comprises a transparent substrate to be used for a phase-shifting mask or a semiconductor wafer to be used for an integrated circuit.
The resist layer is developed after the bombardment, whereby a desired pattern of openings is formed in the resist layer in accordance with the resulting lateral pattern of the charged beam. Then the thus patterned resist layer is used for defining features in the workpiece--i.e., for patterning the workpiece in accordance with the lateral pattern of the beam, using the patterned resist layer as a patterned mask. For example, using a semiconductor wafer as the workpiece, the patterned resist layer is bombarded with ions that are thus implanted into the wafer or that react with the wafer to form indentation ("recess") regions in the wafer. Alternatively, the patterned resist layer is used as a patterned mask for the deposition of patterned metal layers on the wafer, in order to metallize integrated circuits. Using a transparent substrate (with a patterned layer of opaque portions on typically one of its major surfaces) the patterned resist layer is used as a patterned mask for spatially selectively removing portions of the thickness of the transparent substrate, or portions of the thickness of the opaque layer, or of both--i.e., portions of the workpiece. Moreover, the patterned resist layer is typically completely removed after being used as a patterned mask in conjunction with the semiconductor wafer or with the transparent substrate.
A known method for defining a desired pattern in a resist layer involves exposing the resist layer to a direct-writing, scanning electron beam, followed by wet developing the resist layer, whereby the desired patterned resist layer is formed. One problem that arises is called "charging effects"--that is, electronic charges that are introduced by the electron beam at earlier moments of times during the scanning undesirably laterally defect the electron beam at neighboring locations at subsequent moments of time, whereby the resulting pattern of exposure of the resist layer to the electron beam is not the same as was desired.
In a paper authored by Keiko Yano et al., entitled "A New Process for Reducing the Charging Effect in Electron Beam Lithography," and published in JJAP Series 4, Proc. of 1990 Intern. MicroProcess Conference, pp. 147-150 (1990), a method of patterning an electron-beam-sensitive resist layer is taught with desirably reduced charging effects. In that method, a direct-writing (scanning) electron beam is used for producing the desired pattern in the resist layer after the latter has been exposed to the beam and has been wet developed, but with the addition of a grounded electrically conductive organic layer overlying the resist layer during the electron beam bombardment of the resist layer, and with the addition of an intermediate protective layer intervening between the conductive organic layer and the resist layer. The conductive organic layer is transparent to the electron beam, and its purpose is to remove the undesirable charges by conducting them to ground.
The conductive organic layer is formed by spin-coating from a solution of the polymer in an organic solvent. The purpose of the intermediate protective layer is to suppress undesirable global removal of the resist layer by the organic solvent during the spin-coating process. Ibis protective layer can simply be a polyvinyl alcohol (hereinafter "PVA") layer, which can be removed--subsequent to a removal of the conductive organic layer after the electron bombardment has been completed--by means of simply dissolving it in water.
Disadvantages of the foregoing method can arise from a formation and subsequent accumulation of unwanted polymer residues at the interface of the PVA and resist layers. More specifically, the unwanted residues can coat the workpiece and thus render it difficult to transfer the pattern of the patterned resist layer to the workpiece. Disadvantages can also arise from the random localized formation of unwanted pinholes in the resist layer during the removal of the conductive organic layer, owing to the porousness of the PVA layer and to the solubility of the resist in the organic solvent that is used to dissolve the conductive organic layer. More specifically, pinholes in the protective layer enable the solvent, which is subsequently used for removing the conductive organic layer after the electron bombardment has been completed, to penetrate down to, and to dissolve localized portions of, the resist layer. Therefore, alleviation of one or both of these disadvantages is desirable.

Electron beam lithography with reduced charging effects


A sludge protector canopy baffle system for use in a clarifier tank with a tank bottom, and peripheral vertical wall bounding the interior of the tank is formed by a plurality of individual perforated baffles interconnected and supported by other components of the tank forming a rigid ceiling of sloped and curved perforated baffles allowing the incoming water to pass on its surface minimizing sludge re-suspension and directing the flow on top of the blanket in the settling zone of the tank. Each baffle has a curved surface in the lateral direction to allow drainage of solids and openings to allow gas release and water flow. The baffles are interconnected along the length by cross connectors to ensure rigidity. The resulting system provides a sludge protector canopy baffle system by which the water flows uniformly through the tank without disturbing or re-suspending settled or thickened sludge and overall tank performance is enhanced.

1. Field of the Invention
This invention relates to a system of interconnected sludge protector canopy perforated baffles for use in solids separation and settling tanks, the baffle system consisting of a plurality of interconnected perforated baffles attached to other components of the tank and forming a rigid ceiling of sloped and curved perforated baffles covering the sludge layer at the bottom of the tank.
2. Description of the Related Art
The present invention relates to a baffle system for a tank for separation of solids from the water by gravitational forces in water and wastewater treatment. The tank where the inventive baffle device is used is typically circular, square or rectangular in shape.
In water and wastewater treatment where sedimentation tanks, also known in the art as clarifiers or settling tanks, are used, the efficiency of the tanks is governed by the amount suspended matter removed and the quality of the sludge produced from the bottom of the tank. The energy and momentum of the flow entering the tank as well the density currents resulting from the difference in specific gravity between suspended matter and water or the differential temperature between the atmosphere and the water contained in the tank represent a major deterrent to the tank removal efficiency and quality of the sludge produced. High level of energy of the flow entering the tanks and/or strong density currents create strong water fall that disturbs the sludge blanket leading to sludge re-suspension and deterioration of tank performance.
Representative examples of prior art of baffles and the like are disclosed in U.S. Pat. No. 2,702,124 to Stengel, U.S. Pat. No. 3,175,692 to Edgerton, U.S. Pat. No. 3,486,628 to Darby, U.S. Pat. No. 3,966,617 to Zaenkert, U.S. Pat. No. 4,270,676 to Green, U.S. Pat. No. 4,985,148 to Monteith, U.S. Pat. No. 5,378,378 to Meurer, U.S. Pat. No. 5,384,049 to Murphy, U.S. Pat. No. 5,714,068 to Brown, U.S. Pat. No. 6,099,743 to Pederson, U.S. Pat. No. 6,276,536 to Esler and U.S. Pat. No. 6,800,209 to Wright. All these inlet designs focused on dissipating the energy of the incoming water to improve settleablity of the sludge without providing protection to the settled and thickened sludge or prevention of sludge re-suspension.
Other representative examples of prior art are disclosed in U.S. Pat. No. 7,637,379 to Pophali et al., U.S. Pat. No. 7,981,299 to Triglavcanin, U.S. Pat. No. 8,021,559 to Triglavcanin, U.S. Pat. No. 8,087,518 to Kwon et al., and U.S. Pat. No. 8,182,701 to Lake. Some of these inventions presented apparatus for improving thickening of sludge or complete clarifier feed structures comprised of a series of energy dissipating, flocculation and short circuiting baffles. None of the above mentioned inventions was intended to protect sludge blanket only neither could be applied to all tank shapes, circular, rectangular or square.
Moreover, no prior art reference discloses a plurality of interconnected individual perforated baffles sloped in all directions with each baffle containing gas release and water flow-through openings and curved in lateral direction to allow drainage of solids and supported on one or both ends to a structural element within circular, rectangular or square tank.
It is, therefore, an object of the present invention to provide a system of plural, interconnected perforated baffles, supported from the circular feed well, center column and/or energy dissipating tub in case of circular tank or alternatively, attached to the tank inlet wall in case of non-circular tank, forming a rigid ceiling of curved baffle system covering the sludge blanket.

This patent is subject to a terminal disclaimer.


A monitoring system includes a plurality of monitoring devices adjacently provided to a group of integrated fuel cell stacks for measuring a voltage of the fuel cell units. Each of the monitoring devices includes a plurality of monitoring sensors adapted for electrically connecting to a predetermined set of fuel cell units and a MCU (Micro-Chip-Unit) for sequentially and circularly switching each two neighboring monitoring sensors for reading the voltage of each respective fuel cell. A CAN bus is provided for electrically and collectively interconnecting the monitoring devices with a central operator which is arranged in such a manner that when said the voltage of the respective fuel cell unit exceeds a safety range, the central operator generates an alert signal for indicating an abnormal operation of the respective fuel cell.

1. Field of Invention
The present invention relates to fuel cells, and more particularly to a monitoring system for fuel cell stack by monitoring the output voltage of each cell unit of the fuel cell stack to ensure the fuel cell stack working under an optimum condition.
2. Description of Related Arts
Electrochemical fuel cell is a kind of electrochemical energy conversion device which is capable of converting the hydrogen and oxidant into electrical energy. The core component of such device is the membrane electrode assembly (MEA). The MEA comprises a proton exchange membrane sandwiched by two porous sheets made of conductive material such as carbon tissue. Catalyst like metal platinum powder, adapted for facilitating the electrochemical reaction, are evenly and granularly provided on two carbon tissue sheets to form two catalytic interfaces. Furthermore, electrically conductible members are provided on two sides of the MEA to form a cathode and an anode in such a manner that electrons generated due to the electrochemical reaction are capable of being lead out through an electrical circuit.
The anode of the MEA is supplied with fuel, such as hydrogen, for initiating the electrochemical reaction. The fuel is forced through the porous and diffused carbon tissue sheet, and loses electrons to form positive ions on the catalytic interface due to the electrochemical reaction. The positive ions are capable of transferably penetrating the proton exchange membrane to reach the cathode. On the other hand, an oxidant-containing gas, such as oxygen and air, is supplied to the cathode of the MEA, wherein the oxidant-containing gas penetrates the porous and diffused carbon tissue sheet to generate negative ions due to the electrochemical reaction occurred on the catalytic interface. Finally, the positive ions transferred from the anode meets the negative ions to form reaction product.
The fuel cells employ hydrogen as the fuel and oxygen containing air (or pure oxygen) as the oxidant. The fuel hydrogen forms hydrogen positive ions (protons) at the anode portion due to the electrochemical reaction. The proton exchange membrane is capable of facilitating the hydrogen positive ions to migrate from the anode to the cathode. In addition, the proton exchange member also separates the hydrogen gas flow and the oxygen gas flow to prevent the mixture of hydrogen and oxygen as well as the explosive reaction therefor.
Oxygen obtains electrons from the catalytic interface to form negative ions at the cathode portion of the fuel cell due to the electrochemical reaction. The negative ions reacts with the hydrogen positive ions transferred from the anode portion to form reaction water product. In the fuel cells which utilize the hydrogen as the fuel and oxygen containing air as oxidant, the electrochemical reaction can be expressed by the following formula:Anode: H2→2H++2eCathode: ½O2+2H++2e→H2O
In the typical proton exchanging membrane fuel cell system, the MEA is disposed between two electrically conductible electrode plates wherein the contacting interface of each electrode plate defines at least one flowing channel. The flowing channel could be embodied by conventional mechanical method such as pressure casting, punching, and mechanical milling. The electrode plate could be embodied as metal electrode plate or graphite electrode plate. So the flowing channels provided on the electrode plate are capable of respectively directing fuel and oxidant into the anode portion and the cathode portion positioned on opposite sides of the MEA. For a single fuel cell structure, only one MEA is provided and disposed between an anode plate and a cathode plate. Here, the anode plate and the cathode plate not only are embodied as current-collecting device, but also as a supporting device for securely holding the MEA. The flowing channels provided on the electrode plates are capable of delivering fuel and oxidant to the catalytic interfaces of the anode and cathode, and removing the water discharged due to the electrochemical reaction of fuel cell.
To increase the overall power output of the proton exchanging membrane fuel cell, two or more fuel cells are electrically connected in series in a stacked manner or a successive manner to form a fuel cell stack. In such stacked series manner, each electrode plate provides flowing channels on opposite side of plate respectively wherein one side of the electrode plate is applied as an anode plate contacting with the anode interface of a MEA, while another side of the electrode plate is applied as a cathode plate contacting with the cathode interface of an adjacent MEA. That is to say, one side of such electrode plate serve as an anode plate for one fuel cell unit and the other side of plate serve as a cathode plate for the adjacent cell. This kind of structure is called bipolar plate. Conclusively, the fuel cell stack comprises a plurality of fuel cell units electrically connected with each other, and a pair of end plates disposed at two ends of such stack for securing the plurality of fuel cell units in position.
It is well known that fuel cell stack is used as power system for propelling vehicles and vessels, and for operating other electrically operated machines such as portable generators.
To support such powerful operator, a plurality of individual fuel cell units, commonly hundreds or thousands of fuel cell unit, is interconnected in series manner. As a result, a monitoring system is very important for monitoring the voltage output of each single fuel cell unit in order to prevent abnormal operation, such as overcurrent or excess working temperature of the fuel cell stack.
Accordingly, the overall output voltage of the fuel cell stack is determined by the accumulation of the outputs of the individual fuel cells electrically connected in a series manner. Therefore, when one of the individual fuel cells fails to operate, the overall performance of the fuel cell stack would be downgraded. In other words, it is crucial to monitor the performance of individual cell to ensure the overall performance of the fuel cell stack in good shape. Especially, when an electrode is disruptive, the voltage output of such electrode will reach an abnormal value, such as a value close to zero, or even a negative value. In contrary, the voltage output value of a normal fuel cell unit should be within a range between 0.5–1.2V. And more importantly, the extended service of such abnormal fuel cell unit would cause severe consequences. Therefore, it is necessary to monitor every single fuel cell unit of a fuel cell stack that, whenever certain fuel cell units monitored indicated an abnormal voltage value, the controlling system of such fuel cell stack would be able to provide alert or alarm signals and to shut down the whole system.
Shanghai Shenli Co. introduced an innovative device and method for monitoring voltage of individual fuel cell unit of a fuel cell stack, Chinese Patent No. 02136838.4. According to Shenli's invention, the live voltage output of each fuel cell unit could be directly measured and that once an abnormal voltage is detected, an alerter is provided for initiating an order for protecting the fuel cell stack.
Referring to the FIG. 1, the conventional monitoring device comprises a MCU (micro chip unit) processor which has an A/D converter and a plurality of switches, and a plurality of measuring lines extended from individual fuel cell unit of the fuel cell stack to electrically couple with the plurality of switches respectively, wherein each of the measuring lines is electrically connected to the A/D converter via a decoding matrix, such that a voltage signal is sent out from each of the measuring lines to the MCU processor through the decoding matrix for monitoring the voltage output of each of the individual fuel cells.
Theoretically, the above mentioned monitoring system would be effective in practice. However, in case the fuel cell stack to be monitored contains too many fuel cell units or there are several fuel cell stacks needed to be monitored simultaneously, such monitoring device would suffer some unavoidable drawbacks. First of all, the RS485 communicating mode is vulnerable in reliability and inefficient in transmitting speed. Second, as shown in FIG. 1, a plurality of corresponding decoding matrix circuit would be needed for facilitating the operation. Unfortunately, such decoding circuits are rather bulky and not suitable to be used for large scale fuel cell stacks. Third, since there is considerable number of measure lines, the leading wires for such monitoring system would be lengthy. Fourth, the prolonged leading wires are susceptible to be interfered by surrounding environments thus worsening the stability and reliability of the fuel cell stack. Finally, the assembly process of the monitoring system is rather complicated and awesome for common operators.


An electronic mail archiver for use in a computer system includes a user interface that allows a user to identify an electronic mail message to be archived from an electronic mail system, and a message transfer component that automatically retrieves the message from the electronic mail system in an electronic mail format and stores the message in a format defined by a data processing application capable of running in the computer system.

The invention relates to archiving messages.
Referring to FIG. 1, in a typical computer network a client computer 20 utilizes services provided by network servers, such as an electronic mail server 22 and a shared information (e.g., data processing) server 24. A single computer or multiple computers may serve as the electronic mail server 22 and the data processing server 24. If the servers 22 and 24 comprise different computer systems, each system includes at least one central processor 21, 23.
Within the client computer 20 are a central processor 25 and client software packages 26, 28 that allow the client computer to communicate with the network servers 22, 24. Each server 22, 24 is equipped with a corresponding network storage device 30, 32, such as a hard drive, that allows the server to store information needed to provide its services to the client computer 20. The client computer 20 also is equipped with a storage device 34 that stores information needed by the computer 20 to perform its assigned tasks. The client computer 20 also includes a display 36 that the electronic mail and data processing packages 26 and 28 use to provide information to a user.
The electronic mail server 22 allows the client computer 20 and other clients to send and receive electronic mail messages among themselves. Within the corresponding storage device 30, the electronic mail server 22 maintains a mail storage area 38 (i.e., a mailbox) for each client computer connected to the server 22. The mailbox 38 stores electronic mail messages 40 generated and received by the client computer 20. With most electronic mail systems, copies of messages 40 held in the mailbox 38 may be stored on the local storage device 34 and later viewed on the display 36 through the electronic mail client package 26.
The data processing server 24 allows the client computer 20 and other clients to share data stored in the corresponding storage device 32. The data processing client package 28 in the client computer 20 passes data to and from the server 24 and displays the data to the user via the display 36. Data stored on the network storage device 32 also may be stored on the client computer's local storage device 34 for later use by the data processing client 28. The data processing server 24 also may have a search engine or search function 29 that allows a user to find certain information quickly.

Sharing an electronic mail message with a party not named as a recipient of the message


A method of generating error correction parity information using a parity check matrix having m rows and n columns, wherein m is a number of parity bits and n is a number of codeword bits, wherein a same fixed number of elements in each of the rows has a value of 1 and all remaining elements in each of the rows has a value of 0, and wherein a same fixed number of elements in each of the columns has a value of 1 and all remaining elements in each of the columns has a value of 0, the error correction method including generating a lower triangular matrix in 1st through k-th rows and (n−m+1)-th through (n−m+k)-th columns of the parity check matrix by performing row and column permutations on the parity check matrix, wherein k<m; and obtaining m parity bits using the parity check matrix including the lower triangular matrix and (n−m) message bits.

1. Field of the Invention
An aspect of the invention relates to error correction and signal detection, and more particularly, to a method and apparatus for generating error correction parity information.
2. Description of the Related Art
A coding method using Low Density Parity Check (LDPC) codes for error correction creates a parity check code including predetermined numbers of "ones" in the rows and columns of an error correction code (ECC) block, and generates parity information using the parity check code.
More specifically, a parity check matrix H is created that includes a predetermined number of "ones" in the matrix columns and rows, and a codeword x satisfying the equation "Hx=0" is obtained. Here, the codeword x relates original data to parity information. For performing this calculation, the parity check matrix H is first transformed into a generator matrix G using Gaussian elimination, or transformed into a lower triangular form.
However, the generator matrix G requires large calculations due to the absence of sparseness of the original matrix. Also, the lower triangular form requires a complicated calculation process.
A conventional parity check matrix H is shown in FIG. 1. The following Equation (1) represents a lower triangular form of the calculation process for generating a codeword x satisfying "Hx=0". As apparent from Equation (1), the calculation process is complicated.
                                          H                                      [                                                                                A                                                                                B                                                                                T                                                                                C                                                                                D                                                                                E                                                                                ]                                →                      H            ×                          [                                                                    1                                                        0                                                                                -                                              ET                                                  -                          1                                                                                1                                                              ]                                      =                  [                                                    A                                            B                                            T                                                                                -                                              ET                                                  -                          1                                                                                A                                    +                  C                                                                                -                                              ET                                                  -                          1                                                                                B                                    +                  D                                                            0                                              ]                                    (        1        )            P1=−Φ−1[−ET−1AST+CST],φ=−ET−1B+D,P2=−T−1[AST+BP1T]
A basic concept for LDPC coding is disclosed in "Good Error-Correcting Codes Based on Very Sparse Matrices," by D. J. C. MacKay, IEEE Transactions on Information Theory, Vol. 45, No. 2, pp. 399-431, March 1999, and a technique for coupling the parity check matrix H is disclosed in "Efficient Encoding of Low-Density Parity-Check Codes," T. Richardson and R. Urbanke, IEEE Transactions on Information Theory, Vol. 47, No. 2, pp. 638-656, February 2001.

Method and apparatus for generating parity information for error correction


A reversible bedcovering assembly, including a main bedcovering having an inward section surrounded by an edge section and at least two side portions attached to the edge section and depending therefrom when installed on a mattress or bed. Each side portion is adjacent at least one other side portion and forms a void therebetween. A gusset insert is provided to substantially fill the void between adjacent side portions, each gusset insert having a top portion and a drape portion attached thereto. Each gusset insert is attached to the main bedcovering adjacent the edge section.

This invention relates to a bedcovering assembly and, more particularly, to a reversible bedcovering assembly. The general purpose of this invention is to provide a bedcovering assembly in a gusset style giving a tailored, fitted style to a bedcovering. In one embodiment, the bedcovering is reversible, such that a single bedcovering can be utilized in either of two configurations, allowing for either the front or back face fabrics of the bedcovering to be exposed to view.
The present invention, in one aspect, is a bedcovering assembly that includes a main bedcovering having an inward section surrounded by an edge section and at least two side portions. Each side portion has a length, which when installed on a mattress or bed, terminates adjacent the floor upon which the bed or mattress rests, and is attached to and depends from the edge section. Each side portion is adjacent at least one other side portion, and the adjacent side portions form a void therebetween. One or more gusset inserts are included within the bedcovering assembly for each void. Each gusset insert has a top portion and a drape portion attached to the top portion, the length of each gusset insert being substantially equal to the length of the side portions. Each gusset insert is attached to the main bedcovering adjacent the edge section with a fastener assembly, which can be a button or buttons, hook and loop fasteners, snap fittings, buckles or the like. When properly installed, the gusset insert is capable of substantially filling the void formed between adjacent side portions.
In another aspect, the bedcovering assembly is reversible. In such an embodiment, the main bedcovering further includes a first surface and an opposite second surface, each capable of displaying an aesthetically pleasing appearance so that the main bedcovering may be displayed with a selected one of either the first surface or the second surface exposed to view. Further, each gusset insert includes a first surface and an opposite second surface, each surface similarly capable of displaying an aesthetically pleasing appearance so that the gusset inserts may be displayed with a selected one of either the first surface or the second surface exposed to view.
In another aspect, the invention is a method of installing a bedcovering on a mattress that has a mattress surface and a mattress perimeter. According to the invention, the main bedcovering is spread over the mattress and positioned such that the edge section is substantially aligned with the mattress perimeter. A gusset insert is attached to the main bedcovering adjacent the edge section between two adjacent side portions with a fastener assembly and arranged between the two adjacent side portions to substantially fill the void formed between the side portions.
In yet another aspect, the invention is a method of installing a reversible bedcovering on a mattress that has a mattress surface and a mattress perimeter. According to this aspect of the invention, the user selects one of a first surface or an opposite second surface of the main bedcovering to be exposed to view and spreads the main bedcovering over the mattress with the selected surface exposed to view and with the surface not selected facing the mattress. The main bedcovering is positioned on the mattress, and a gusset insert is attached to the main bedcovering on the surface not selected adjacent the edge section between two adjacent side portions with a fastener assembly. The gusset insert is arranged between two adjacent side portions to substantially fill the void formed between the side portions.
Further, the present invention comprises a gusset insert for a bedcovering on a mattress or bed, wherein the bedcovering has an inward section surrounded by an edge section and at least two side portions which depend from the edge section in a generally juxtaposed relationship when the bedcovering is on the mattress or bed. The respective side portions form an opening or void therebetween and the gusset insert is installed by suitable fastening means to substantially fill the opening or void.


The present invention relates to a method for assigning frequency spectrum bandwidth of an OFDM and OFDMA coexistence system, and the base station system combines uplink and downlink data containing OFDM sub-frames and OFDMA sub-frames in a time division fashion, assigns the frequency spectrum reasonably according to the different bandwidth requirements of the OFDM and the OFDMA and the use condition of the frequency band, and constitutes a frame structure realizing the coexistence of the OFDM and the OFDMA, so as to send the OFDMA uplink/downlink data and the OFDM uplink/downlink data. The method for assigning frequency spectrum bandwidth according to the present invention can achieve a higher frequency spectrum utilization efficiency of an OFDM and OFDMA coexistence system, avoid the waste of the frequency spectrum resource of a service provider; and can also realize more flexible networking.

Orthogonal frequency division multiplexing (OFDM) technology was firstly used in military field in 1960s, the modulating mode has very high frequency spectrum utilization efficiency and is suitable for wireless data transmission, so it has been used widely as a wireless access method.
OFDM system adopts multi-carrier technique, and a high speed data stream is transmitted by serial to parallel convert, so that the duration of data symbols in each sub-carrier increases relatively, and then the ISI (InterSymbol Interference) brought by the time dispersion of wireless channel could be reduced efficiently, thereby reducing the complexity of balance in a receiver, and even avoiding using an equalizer and only using the method of inserting cyclic prefix to eliminate the unfavorable influence of ISI. Orthogonality exists among the sub-carriers of the OFDM system, which permits mutual overlap of the frequency spectrum of each sub-carrier, and therefore, compared with the conventional frequency division multiplexing system, the OFDM system could maximize the use of frequency spectrum resources. FIG. 1 is a time domain wave shape view of an OFDM symbol in which the prefix is inserted cyclically.
In FIG. 1, Tb represents the effective symbol cycle in OFDM signals, Tg represents the inserted cyclic prefix, and the contents of Tg is the copy of the last part of contents in Tb period, and Ts is the cycle of the whole OFDM symbols. As long as the length of the cyclic prefix is longer than the maximum time delay extension of OFDM symbols, the orthogonality of each sub-carrier in one OFDM symbol can be guaranteed. And therefore, the multi-path interference could be overcome through inserting the cyclic prefix Tg periodically. It is usually required that the cyclic prefix should be bigger than or equal to 2 to 4 times of the maximum time delay extension when design an OFDM system, and table 1 shows the maximum time delay extension in common environments.
TABLE 1environmentmaximum time delay extensionIndoor40 ns~200 nsoutdoor1 μs~20 μs
It can be seen from table 1 that if the OFDM system only needs to support the wireless communication in indoor environment, usually the cyclic prefix should be bigger than 800 ns, whereas if the outdoor wireless communication needs to be supported, the cyclic prefix should be bigger than 20 μs, and because of the limitation of the time delay extension, in the condition that the FFT dots are fixed, the OFDM system should not adopt a too wide bandwidth.
In a broad sense, the OFDM system comprises OFDM and OFDMA systems, and OFDMA has the similar basic principle to that of the OFDM, while the difference of the two lies in that the bandwidth assignment of the OFDMA system is carried out in the two-dimensional interval of time and frequency, and the bandwidth of the OFDM system is only assigned on time dimension. Compared with the conventional OFDM system, the bandwidth assignment of the OFDMA system is more flexible and suitable for use in cellular networking, so it is attracting people's attention more and more.
The IEEE802.16 standard adopts OFDM and OFDMA techniques, but the two kinds of techniques are independent of each other relatively in the standard, and there is not any special definite provision on cooperative work of the two systems. From the point of compatibility, research on the coexistence system of OFDM and OFDMA is needed so that the future system could support OFDM and OFDMA techniques at the same time, and it could furthest protect the interests of investors and users.
Furthermore, to implement the coexistence of OFDM and OFDMA, it is needed to consider not only the compatibility of the frame structure to different systems, but also the limitation of cyclic prefix on the bandwidth of OFDM system and OFDMA system.
The calculating formula of the cyclic prefix in OFDM symbols is as follows:
            T      g        =                  G        ·                  T          b                    =                        G          ·                      N            FFT                                                n            ·            BW                                                                          ,
wherein n is an over-sampling factor, and as for the OFDM system, the value of n relates to the bandwidth, and its range is basically between 1.14 to 1.15, but to an OFDMA system, the value of n generally is 8/7. And G is the cyclic prefix factor, which has 4 values as follows: ¼, ⅛, 1/16, and 1/32. NFFT is the number of FFT dots.
From the formula, it can be seen that the length of the cyclic prefix is in direct proportion to G, is in inverse proportion to the bandwidth, and is in direct proportion to the number of the FFT dots. Generally speaking, the number of the FFT dots adopted by the OFDM system is smaller than that of the OFDMA system, and the OFDM system generally adopts the FFT of 256 dots, while the OFDMA system adopts the FFT of 2048 dots. To the OFDM system of 256 dots, because of the limitation of the cyclic prefix, the bandwidth can not be too wide, but to the OFDMA system of 2048 dots, in the condition of the same time delay extension, as the number of the FFT dots is 8 times as that of the OFDM system, the largest bandwidth that the OFDMA system could adopt also is 8 times as that of the OFDM system. When the OFDMA system carries out cellular networking, the bandwidth should not be too small in order to guarantee the capacity of the system. Table 2 shows the range of the cyclic prefixes of OFDM of 256 dots and OFDMA of 2048 dots in every usable bandwidth condition as follows:
TABLE 2Minimum cyclicMaximum cyclicFFT dotsbandwidthprefixprefix25610MHz700ns5.6μs2567MHz1μs8.02μs2563.5MHz2μs16.04μs2561.75MHz4μs32.08μs2565.5MHz1.45μs11.64μs2563MHz2.67μs21.3μs204820MHz1.4μs11.2μs204810MHz2.8μs22.4μs204828MHz2μs16.04μs204814MHz4μs32.08μs20487MHz8μs64.16μs20483.5MHz16μs128.32μs204817.5MHz3.2μs25.66μs20488.75MHz6.4μs51.32μs20481.25MHz35.6μs284.44μs
From table 2, it can be seen that if it is desired to ensure the bandwidths of the OFDM system and the OFDMA system are the same, because of the impact of the maximum time delay extension, the bandwidth should not be too high, and if the capacity of OFDMA system is taken into consideration, the bandwidth that the OFDMA system adopts should not be too low, either. Owing to the above two reasons, the bandwidth which the OFDMA system adopts may be different from that of the OFDMA system. When the bandwidths of the two systems are remarkably different from each other, to the OFDM and OFDMA time division combined frame fashion in the conventional time division fashion, the utilization rate of frequency spectrum will be very low.
Therefore, in order to improve the utilization efficiency of the frequency spectrum of the OFDM and OFDMA coexistence system, it is necessary to design an efficient method for assigning the frequency spectrum bandwidth of the system.

Method for assigning frequency spectrum bandwidth of an OFDM and OFDMA coexistence system


An apparatus for electronically obtaining and interpreting the closely focused digital image of a substance has a housing, a light generation source, an optical sensor, an electronic control/input/processing/storage/output unit a display, an optional printer and optional data output ports. The electronic control/input/processing/storage/output unit controls the light generation source, which generates light, which light diffused through and over the substance and is sensed and converted to electrical impulses by the optical sensor array, which collective electrical impulses represent the closely-focused digital image of the substance, which digital image can be interpreted to report the relative quality of the substance.

The present invention relates to an apparatus for obtaining and electronically interpreting closely-focused digital images of liquids, solids and combinations of liquids and solids (which are hereinafter referred to individually as "substance" or collectively as "substances") being subjected to controlled quantities and qualities of light shining through and over such substance. More particularly, but not exclusively, one detailed described embodiment of the present invention set forth herein and referred to as a container-receiving embodiment relates to obtaining and electronically interpreting closely-focused digital images of wine in a sealed wine bottle or blood in a test tube. In addition, another detailed described embodiment of the present invention set forth herein and referred to as a handheld embodiment relates to obtaining and electronically interpreting digital images of substances in open containers, pools and piles or blood in capillaries.
The relative quality of many liquid, solid and combination of liquid and solid substances can be interpreted from various optical characteristics of those substances. Various optical arrangements are known for measuring and analyzing the various optical characteristics of test samples, such as spectrophotometers. The prior art devices, however, are typically bulky, expensive, require a high degree of operator skill and expertise, and usually require opening the container of substance and placing a sample of the substance being assayed into a carrier that is then further processed, placed in the testing apparatus and tested. The present invention is designed to simply and economically capture a closely focused digital image of a substance while the substance is being subjected to a controlled light at various times during the manufacturing, transportation, sales, use and consumption cycle.
One use of the present invention is to obtain and store closely focused digital images of a substance at various stages of the manufacturing, transportation, sales, use and consumption cycle. By comparing the closely focused digital images obtained at the optimal stage of the manufacturing or packaging process and comparing the baseline digital images with subsequent digital images, one can detect differences in the digital images that indicate differences in the quality of the substance. In addition, one can program the electronic component of the present invention to ascertain and store distinct optical characteristics of a particular substance in a data table that correlates those distinct optical characteristics with other subjective sensory and other otherwise objectively measurable qualities of the substance in order to develop a correlative database that may be used to predict the "quality" of the substance based upon its distinct optical characteristics.
Many substances that are manufactured and sold in sealed transparent or translucent containers will degrade if the container and the substance contained therein are not properly cared for. Most of the prior art devices for testing whether the quality of a particular substance has been maintained require opening sealed containers of the substance for sampling and testing. For example, a consumer who wants to assess the quality of wine contained in a sealed bottle cannot presently do so without opening the bottle, which exposes the liquid contained therein to air containing both oxygen and aerobic bacteria, either one or both of which will promptly begin to act to degrade the wine. In addition, the need often arises to test the quality of substances contained in large bulk containers, vats, or natural land surface pools or piles in situations where obtaining a sample for use in a remote prior art device or transporting an unwieldy prior art device to the substance to be assayed is unfeasible. Finally, the prior art devices usually assay distinct optical characteristics, such as absorption of various light spectra or the presence of particular substances, which assays usually are performed using means requiring expensive equipment or expensive reagents. An economical alternative to the prior art testing means is to obtain a closely-focused digital image of a specific substance known to be in an "optimal" condition, interpreting that digital image and maintaining a database of such closely-focused digital images for comparison with subsequent digital images of the same substance obtained at later stages of sales and delivery cycle and prior to consumption in order to assure the continued quality of the substance.
There is thus a widely recognized need for, and it would be highly advantageous to have, an apparatus that would allow for obtaining and electronically interpreting the closely focused digital images of substances contained in sealed transparent containers, including but not limited to bottles of wine, without having to break the seal on such containers. In addition, there is also a widely recognized need for an economical and highly portable apparatus that can be used for obtaining and electronically interpreting the digital images of substances contained in large bulk liquid containers, vats, and open pools and piles. Finally, there is also a widely recognized need for a quality assurance mechanism for testing the optical characteristics of substances economically by obtaining and interpreting their digital images instead of other optical characteristics using prior art devices.
The aim of the present invention is to provide an improved apparatus which overcomes or substantially reduces at least some of the drawbacks and limitations of the prior art by allowing for obtaining and electronically interpreting a closely focused digital image of a substance at the time that the substance is being subjected to controlled qualities and quantities of light shining through and over the substance. The preferred embodiments of the present invention are capable of obtaining and interpreting such closely-focused digital images of substances contained in transparent containers, large bulk containers, vats and open pools or piles without having to open the containers or remove discrete samples of the fluids and solids being assayed.

Apparatus for obtaining and electronically interpreting digital images of liquids, solids and combinations on liquids and solids


An apparatus is provided for detecting the loss of an input clock signal for a phase-locked loop (PLL). The apparatus includes a time delay circuit, a first frequency divider and a digital logic circuit. The time delay circuit receives the input clock signal and outputs a first time-delayed clock signal. The first frequency divider receives an input signal from an internal clock of the PLL and outputs a clock signal having the same frequency or a lower frequency than that of the time-delayed clock signal. The digital logic circuit that receives the first frequency divider output signal and the first time-delayed clock signal and outputs a signal indicating the loss of the input clock signal if there is no first time-delayed clock signal for a cycle of the first frequency divider output signal.

A Phase-Locked Loop (PLL) is a closed-loop control circuit that produces an output signal which bears a relation to the frequency and phase of an input signal. The input signal is often considered a reference signal. A PLL can be of digital (DPLL) or analog (APLL) design. Each design has somewhat different structure, but both perform the same function. The reference signal is typically called an input clock signal (INCLK). Often, it is necessary for the PLL to take an action when the INCLK is lost. A conventional circuit for detecting the loss of an input clock is shown in diagram form in FIG. 1. In this circuit, the voltage at node F (Vf) is compared in the COMPARATOR circuit to determine if Vf bears a predetermined relationship with either a pre-designated voltage or a threshold voltage determined from the Vdd voltage of an inverter that can be incorporated within the COMPARATOR circuit. If the comparison between Vf and the pre-designated voltage or the threshold voltage falls outside of a particular tolerance, then the NOCLK output is triggered to signal that the INCLK has been lost. Circuits like those shown in FIG. 1 are problematic in determining the loss of INCLK because they are analog and Vf is dependent on factors such as the value of resistor R, the value of capacitor C, the combined resistive/capacitive (RC) effect, the delay td circuit, the NAND gate A, the circuit's Vdd voltage, and temperature. It is desirable to provide a digital circuit that is capable of detecting the loss of the INCLK of a PLL that does not rely on voltage references that are influenced by factors prevalent in analog circuits such as shown in FIG. 1.

Apparatus and method for detecting the loss of an input clock signal for a phase-locked loop


Before applying a processing laser beam to a surface of a substrate through a film of liquid, distance M2 between a reference point on an axis of a first laser displacement meter and the surface of the substrate is measured to correct distance M1 between a lower end of an optical unit and the surface of the substrate, on the basis of distance M2, the processing laser beam is applied to the surface of the substrate, thereby cutting and removing a part of the surface of the substrate, and a depth to which the surface of the substrate has been cut and removed with the processing laser beam is measured by a second laser displacement meter.

1. Field of the Invention
The present invention relates to a laser processing apparatus and a laser processing method, in which liquid is applied to a surface of a substrate such as a semiconductor wafer or a glass substrate for use in liquid crystal displays, the substrate covered with liquid is scanned with a laser beam, and the surface of the substrate is thereby processed.
2. Description of the Related Art
Methods of manufacturing semiconductor devices include steps of processing the surface of a substrate, by using a laser beam. Among these steps are: a step of processing a thin film such as an insulating film, a metal film or a resist film; a step of cutting dicing lines; a step of removing resist films from alignment marks before exposing the substrate to light (i.e., step of exposing the alignment marks). Jpn. Pat. Appln. KOKAI Publication No. 2002-224878, for example, describes a laser dicing process in which the surface of a substrate is scanned with a laser beam, thereby cutting dicing lines in the surface. Jpn. Pat. Appln. KOKAI Publication No. 2003-249427 discloses a process in which a laser beam is applied to a substrate before exposing the substrate to light, in order to remove a resist film covering alignment marks formed on the substrate, thereby to expose alignment marks. Laser beams are preferable for use in these processes, because they have a high energy density, making it possible to accomplish high-precision alignment.
Jpn. Pat. Appln. KOKAI Publication No. 2002-224878, mentioned above, discloses a laser processing apparatus. As FIG. 1 shows, the apparatus has a cup 11, a drive mechanism 12, and a chuck 13. The chuck 13 is provided in the cup 11. The drive mechanism 12 can rotates the chuck 13 and move the chuck 13 in the X- and Y-directions, positioning the chuck 13. The chuck 13 may hold a substrate 10, which has alignment marks and resist films covering the marks. A laser unit 14 applies a laser beam 18 to the resist films, removing the resist films from the substrate 10. A transparent plate 15 made of quartz glass is spaced a little from the substrate 10, facing the substrate 10. Pure water is kept flowing through gap between the substrate 10 and the transparent plate 15, supplied through an inlet port and drained from the gap trough an outlet port. This prevents dust formed in the laser dicing process from sticking to the surface of the substrate.
In most laser processes, a laser having a focal distance of about 50 μm is employed. If the work is placed at a distance shorter or longer than this focal distance, the laser dicing process cannot cut the resist films formed on the work. To cut dicing lines having a uniform depth, the laser needs to apply uniform energy to the work. Hence, the laser beam 18 should be focused at the surface of the substrate 10 in order to cut a dicing line in the surface of the substrate 10.
To focus the laser beam 18 at any point in the surface of the substrate 10, the substrate 10 must be located at a specific distance from the laser unit 14. To focus the laser beam 18 at any point in the surface of the substrate 10, and focus distances are uniformly adjusted to over the entire surface of the substrate, the surface flatness of the chuck 13 or that of the chuck-moving mechanism for moving the substrate 10 in the X- and Y-directions may be enhanced. If the chuck 13 and mechanism are machined at high precision to enhance their surface flatness, the manufacturing cost and the weight of the laser processing apparatus will inevitably increase.
Even if the chuck 13 and chuck-moving mechanism are improved in surface flatness, the apparatus is still disadvantageous because the chuck-moving mechanism has, for example, a ball screw that moves the chuck 13. When the ball screw is rotated, moving the chuck 13, its inclination angle varies, unavoidably inclining the surface of the chuck-moving mechanism. Further, even if the chuck 13 and chuck-moving mechanism are improved in surface flatness, the laser beam 18 cannot be focused at any point in the surface of the substrate 10, because the substrate 10 warps and has projections and depressions in its surface.

Laser processing apparatus and laser processing method for cutting and removing a part of a surface region of a substrate


A ceiling-embedded ventilation fan includes: a casing provided in a box-shape frame inserted and mounted in a ceiling and having an opening facing an indoor side in a lower face thereof, the casing having a side face formed in a scroll shape and set in a vertical direction, the casing further having a casing intake port in the lower face of the frame and a casing discharge port in a side portion of the frame; a centrifugal blower blade housed in the casing and having a blade intake port facing the casing intake port; and an electric motor which rotates the centrifugal blower blade, wherein the centrifugal blower blade is provided so that an upper side of an axial center thereof is tilted in a direction toward an upstream side of a centrifugal airflow based on a center line of the casing intake port in a direction orthogonal to the casing discharge port.

Patent Document 1 discloses a conventional ceiling-embedded ventilation fan, wherein the fan is connected to a duct placed in a ceiling to communicate with an outdoor environment and is mounted in an embedded manner in the ceiling. FIG. 9 is a sectional view of the ceiling-embedded ventilation fan mounted in the ceiling.
As illustrated in FIG. 9, the ceiling-embedded ventilation fan has frame 104 having a box shape, adapter 106, casing 108, centrifugal blower blade 109, and electric motor 110. Box-shape frame 104 is provided with intake port 102 covered with grille 101 formed in a lower face thereof, and discharge port 103 formed in a side face thereof. Duct 105, which communicates with the outdoor environment, is connected to adapter 106. Casing 108 has a scroll shape having orifice 107 used as an intake port in an interior lower face of frame 104. Centrifugal blower blade 109 is housed in casing 108 to blow air. Electric motor 110 rotates centrifugal blower blade 109.
The conventional ceiling-embedded ventilation fan having the above configuration involves a larger resistance loss, reducing an airflow in the event that some parts of duct 105 are inflected when placed in the ceiling or duct 105 is longer than expected. When using the ceiling-embedded ventilation fan under such an increased resistance loss resulting in a large static pressure, a product specification focusing on the intensity of airflow makes it necessary to increase the outer circumferential speed of an impeller provided in centrifugal blower blade 109. To increase the outer circumferential speed, it becomes necessary to increase the number of rotations of electric motor 110, thus problematically increasing a noise value.
The product specification focusing on the intensity of airflow when the static pressure is high leads to another problem that there is less airflow when the static pressure is low.


A gate charge recovery circuit prevents generation of the voltage spike that would otherwise appear across the sense resistor that is employed to detect the current flowing through the switched terminal of a gate-driven semiconductor device when the device is turned on. The gate charge recovery circuit comprises the combination of a capacitor connected between the reference terminal of the semiconductor device and the positive terminal of a driver and a filter resistor connected between the positive terminal of the driver and the positive terminal of a voltage source.

This invention relates generally to gate-driven semiconductors and more particularly to a gate charge recovery circuit for use therewith. Gate-driven semiconductors widely used in the electronics industry typically include a gate terminal, a reference terminal with respect to which the gate terminal is driven, and a switched terminal. The reference terminal corresponds to the source terminal of a MOSFET or the emitter terminal of an IGBT, for example. Similarly, the switched terminal corresponds to the drain terminal of a MOSFET or the collector terminal of an IGBT. In such semiconductor devices, the driving process involves forcing the gate terminal alternately between a voltage potential to turn the device ON and another voltage potential to turn the device OFF. When the device is ON, the switched terminal exhibits a low impedance characteristic with respect to the reference terminal, whereas when the device is OFF, the switched terminal exhibits a high impedance characteristic with respect to the reference terminal. Since the impedance characteristic exhibited between the gate terminal and the reference terminal is generally capacitive, the process of driving the device from one voltage potential to another is synonymous with forcing a given amount of charge to flow into the gate terminal and out of the reference terminal or vice versa.
In some circuit applications for these devices, it is desirable to detect the current flowing through the switched terminal when the device is ON. This is generally accomplished by inserting a resistor, commonly known as a sense resistor, in series with the reference terminal and detecting the voltage across the sense resistor. This detection method makes use of the approximation that the current flowing out of the reference terminal of the device is representative of the current flowing into the switched terminal of the device. In many applications which use this circuit configuration, the terminal of the sense resistor that is not connected to the reference terminal of the semiconductor device must serve as the ground terminal to provide a common point for one node of a voltage source that is used to drive the device ON.
A general problem with detecting the current flowing through the switched terminal of these gate-driven semiconductor devices is that in the process of turning the device ON, a charge current flows into the gate terminal, out of the reference terminal, and through the sense resistor. As this charge current flows through the sense resistor, a voltage appears across the resistor. Since that voltage is generally present only during a short portion of the full time that the device is ON, it is considered to be a voltage spike. Whereas it is desirable that the voltage waveform across the sense resistor be representative of the current flowing through the switched terminal of the semiconductor device, the voltage spike appearing across the sense resistor represents a deviation from the desired waveform. This voltage spike can present problems in many circuit applications. While attempts have been made to filter the voltage spike, the filtering itself tends to create additional problems.
It is therefore the principal object of the present invention to prevent generation of the voltage spike that would otherwise appear across the sense resistor that is employed to detect the current flowing through the switched terminal of a gate-driven semiconductor device when the device is ON.
This and other objects are accomplished in accordance with the illustrated preferred embodiments of the present invention by providing a capacitor connected between the reference terminal of the semiconductor device and the positive terminal of a driver and a filter resistor connected between the positive terminal of the driver and the positive terminal of a voltage source. As the semiconductor device is turned ON, the capacitor serves to shunt the charge current flowing out of the reference terminal of the semiconductor device back to the positive terminal of the driver, rather than allowing this charge current to flow through the sense resistor. The filter resistor facilitates the shunt function of the capacitor.

Gate charge recovery circuit for gate-driven semiconductor devices


A high torque/high speed brushless DC motor system for controlling both the speed and torque of the motor including a rotor and a stator, the stator of the motor including a first, second and third winding. The system further includes means for sensing the position of the rotor and means for selectively configuring the first, second and third windings of the stator in a wye connection when the speed of the motor is less than a predetermined value and configuring the windings in a delta connection when the speed of the motor is greater than the predetermined value.

1. Field of the Invention
The present invention relates to a brushless DC motor, and more particularly, to a system and method for controlling the torque and speed of the brushless motor.
2. Description of the Prior Art
A typical brushless DC motor includes a stator, including three windings, spaced at 120 degree electrical from one another, for imparting a torque on a rotor. The torque imparted on the rotor causes the rotor to rotate. Those skilled in the art of motors and generators appreciate the efficiency, economy and simplicity of brushless DC motors wherein there is no actual physical contact between the stator windings and the rotor. In order to effectuate the operation of the motor, a properly timed and spaced magnetic field is synthesized in the stator windings which imparts a torque on the rotor and causes the rotor to rotate.
The typical brushless DC motor is permanently configured in one of two basic configurationsxe2x80x94either a wye connection or a delta connection. A motor with windings configured in the delta configuration can operate at a greater speed than the same windings configured in the wye configuration. However, a motor with windings configured in the wye configuration can operate with a greater torque at low speeds than the same windings configured in the delta configuration.
Accordingly, in an application requiring high torque at a low speed, the motor is permanently configured in the wye configuration. Consequently, a conventional brushless motor design requires a compromise between high torque at a low speed and low torque at a high speed.
One application of a brushless DC motor is that of providing a source of motive energy for driving a centrifuge rotor in a centrifuge system. A centrifuge system is a device by which liquid samples may be subjected to centrifugal forces. The sample is carried within the centrifuge rotor, which is mounted to a rotatable drive shaft that is driven by the brushless motor. A centrifuge system using a brushless motor with windings permanently configured in either a delta configuration or a wye configuration is limited by the aforementioned compromise between high torque at a low speed and low torque at a high speed.
There is a need for a system and method for enabling a brushless DC motor to operate with high torque at a low speed for high torque-low speed centrifuge rotors as well as to operate at high speeds at a reduced torque for high speed-low torque centrifuge rotors, thus permitting the use of a wide range of centrifuge rotors.
A high torque/high speed brushless DC motor system for controlling both the speed and torque of the motor includes a rotor and a stator. The stator of the motor includes a first, second and third winding. The system further includes means for configuring the first, second and third windings in a wye connection when the speed of the motor is less than a predetermined value and configuring the windings in a delta connection when the speed of the motor is greater than the predetermined value.
In one aspect of the invention, switching means are included in the motor system for implementing the stator winding connection configuration changes. The switching means of the system can be common to both the wye and delta connection configurations.
A method is also disclosed herein for effectuating the configuration of the brushless DC motor in a wye connection when the speed of the motor is less than the predetermined value and configuring the windings in a delta connection when the speed of the motor is above the predetermined value. The method of the present invention can be further implemented by a storage media containing computer readable program instructions for controlling a processor to control a brushless DC motor in accordance with the methods of the present invention.
It yet another aspect of the invention, a storage media having computer readable program instructions embodied therein for controlling a processor, which in turn, controls a brushless DC motor in accordance with the method of the invention.

Method for enabling a high torque/high speed brushless DC motor


A semiconductor device of the present invention includes a semiconductor region having a first main surface, wherein the semiconductor region includes: alternating n-type pillar layers and p-type pillar layers along the first main surface; a p-type first well layer located within each of the n-type pillar layers at a top surface of the n-type pillar layer; an n-type first source layer located within the first well layer at a top surface of the first well layer; a first side surface dielectric layer located on a side surface in a first trench located at each of boundaries between the n-type pillar layers and the p-type pillar layers, and being in contact with the first well layer and the first source layer; a first bottom surface dielectric layer located on a bottom surface in the first trench, and being at least partially in contact with one of the p-type pillar layers.

In the field of power electronics, a switching element such as a metal-oxide-semiconductor field-effect transistor (MOSFET) and an insulated-gate bipolar transistor (IGBT) is used to drive a load of a motor. Such a switching element is operated by being switched between a low resistance on state and a high resistance off state through input of a control signal. It is important for the switching element to have a high breakdown voltage in the off state as high voltage input is handled in a power electronics application. The high breakdown voltage is typically maintained by the spread of a depletion layer to a drift layer. A higher breakdown voltage can be obtained as the drift layer has a greater thickness, and a higher breakdown voltage can be obtained as the drift layer has a lower impurity concentration because the depletion layer becomes wider.
On the other hand, the switching element is required to have a low resistance in the on state to reduce conduction losses. The resistance of the drift layer is a resistive component of an on-resistance, and is desirably as low as possible. The resistance of the drift layer can be reduced by a decrease in thickness of the drift layer or an increase in impurity concentration of the drift layer. As described above, however, the high breakdown voltage cannot be obtained when the drift layer has a small thickness and a high impurity concentration. Thus, there is a trade-off between the breakdown voltage in the off state and the on-resistance in the on state.
As a structure to improve the trade-off between the breakdown voltage in the off state and the on-resistance in the on state, a super junction structure as disclosed in Patent Document 1 has been proposed. The super junction structure includes strip-shaped n-type pillar layers and strip-shaped p-type pillar layers alternating in a direction perpendicular to a direction of flow of a current while keeping a charge balance so that effective impurity amounts in the respective pillar layers are equal to each other. An effective impurity amount herein is the amount of impurity effectively acting as an acceptor in a p-type semiconductor, and is the amount of impurity effectively acting as a donor in an n-type semiconductor.
By using the super junction structure, the trade-off between the breakdown voltage in the off state and the on-resistance in the on state, which is a problem of a conventional switching element, can be improved. That is to say, a semiconductor device having the super junction structure can reduce the on-resistance while maintaining the breakdown voltage, and can improve the breakdown voltage while maintaining the on-resistance, for example, compared with the conventional switching element.

Semiconductor device having trench gate electrodes formed in first pillars including source layers formed in the first pillars being deeper into the substrate than first source layers in second pillars