A hard disk drive, which includes a main body with a cover for protecting its internal parts, includes at least one dew forming plate with a thermal conductivity greater than that of the cover, the at least one dew forming plate being mounted in a respective opening of the cover so as to collect the dew that would be formed on the internal parts due to the external environment.

1. Field of the Invention
The present invention relates to a disk drive, and more particularly to a technique for preventing dew from forming on internal components of a hard disk drive.
2. Description of the Related Art
The moisture existing on the inside of a hard disk drive exerts a bad influence upon inside components. Especially dew formed in a state of saturation exerts bad effects upon an operation of components. Therefore, it is necessary to prevent dew from being formed inside when manufacturing a hard disk drive. There are normally two techniques to prevent dew from being formed on the inside of a hard disk drive. One technique is to seal the inside of a hard disk drive by using a gasket or a tape. The sealing material of the gasket or tape cutting off the inside of a hard disk drive from the outside has the property of preventing dew from penetrating thereinto, but the cost for preventing dew becomes expensive. Another technique is to use a breather filter. The breather filter is installed on the upper surface of a cover of a main body and it is widely used more than sealing. The breather filter is used for the following reasons.
By a high speed rotation of the hard disk, an air flow is generated on the inside of a hard disk drive and accordingly, a distribution of air pressure occurs. The pressure at the moment is lower than that of the outside of the hard disk drive and accordingly the contaminated outside air flows into the inside of the hard disk drive, resulting in contamination of the inside. An inlet opening is installed for air flow and is formed between the outside to the inside and the breather filter is installed in the opening for allowing clean air to flow in. The inlet opening equipped with a breather filter is used as a vent when the hard disk drive is not being operated. As the air passes out of or into the inside of the hard disk drive, the humidity of the inside is adjusted somewhat. Accordingly, the dew formed in a state of saturation is also somewhat prevented. It is understood that a response of an inside temperature according to an outside temperature is faster than that of an inside humidity according to an outside humidity.
When a hard disk drive using the breather filter is moved from a state of a high temperature and high humidity to a reversed state, dew is formed inside due to the temperature and humidity cycle. When a hard disk drive at a warehouse having a high temperature and humidity is moved to an office having a low temperature and low humidity, dew can be formed on the internal parts of the hard disk drive. The dew exerts bad effects upon inside components of the hard disk drive such as the head and the recording medium.
The following patents each disclose features in common with the present invention but do not teach or suggest a technique for preventing dew from forming on internal components of a hard disk drive utilizing a dew forming plate having a thermal conductivity greater than that of the cover of the hard disk drive as in the present invention.
U. S. Pat. No. 5,590,001 to Ino et al., entitled Breather Filter Unit For Magnetic Disk Drive, U.S. Pat. No. 5,417,743 to Dauber, entitled Self-Adhesive Vent Filter And Adsorbent Assembly With A Diffusion Tube, U. S. Pat. No. 5,293,286 to Hasegawa et al., entitled Magnetic Disk Apparatus For Maintaining An Optimum Humidity In A Head Disk Assembly, U.S. Pat. No. 5,075,807 to Inoue et al., entitled Magnetic Disk Device Including Humidity Controller In Disk Enclosure, U.S. Pat. No. 5,229,899 to Brown et al., entitled Apparatus And Method For Controlling Vapor Phase Within An Enclosure, U.S. Pat. No. 5,057,951 to Eckerd, entitled Breather Vent Assembly Formed In A Sealed Disk Drive Housing, U.S. Pat. No. 5,406,431 to Beecroft, entitled Filter System For Type II HDD, U.S. Pat. No. 5,012,360 to Yamauchi et al., entitled Defumidifier For Magnetic Disk Apparatus, U.S. Pat. No. 5,030,260 to Beck et al., entitled Disk Drive Breather Filter, U.S. Pat. No. 4,967,295 to Yamauchi et al., entitled Humidity Regulating Apparatus For Magnetic Disk Drive, U.S. Pat. No. 4,751,594 to Blanks, entitled Low Diffusion Disk Drive Breather Vent, U.S. Pat. No. 4,863,499 to Osendorf, entitled Anti-Diffusion Chemical Breather Assembly For Disk Drives, U.S. Pat. No. Re. 64,497, to Blanks, entitled Low Diffusion Disk Drive Breather Vent, and U.S. Pat. No. H1067 to Eckerd, entitled Breather Vent Assembly Formed In A Sealed Disk Drive Housing.

Technique for preventing dew from forming on internal components of hard disk drive


A fluid connector comprises a pair of retainers, with a first retainer having a pair of resilient legs extending axially and radially inwardly from an axially outer portion of a housing bore. The first retainer abuts a first upset portion on the tube to secure the tube within the housing. A secondary retainer is positioned axially outwardly of the first retainer, and has legs which also abut a second upset portion on the tube also securing the tube within the housing. The secondary retainer legs preferably extend parallel to the axis of the tube, such that they provide a strong resistance force against pull-out of the tube.

This application in general relates to quick connect fluid couplings for retaining a tube within a housing.
Quick connect coupling are known in the prior art wherein a retainer is received within a housing and secures a tube within the housing. The retainer typically has a plurality of resilient legs extending radially and axially inwardly from an entrance bore of the housing. The tube typically has an upset portion with an outer diameter greater than the nominal outer diameter of the tubing. The tube is inserted into the housing, with the upset portion abutting inner peripheral surfaces of the legs, and flexing them radially outwardly. The upset portion may then move axially beyond an axially inner end of the legs. At that time, the legs resiliently flex radially inwardly, and abut an axially outer surface of the upset portion, retaining the tube within the housing. Such couplings are widely used in the prior art, and have proven quite successful.
The prior art has sometimes experienced failures of such retainers, which allow the tube to move back outwardly of the housing. This is undesirable.

Tube coupling with secondary retainer clip


A method of remediating water or soil contaminated with contaminants including one or more halogenated, phenyl related biphenyl related, triazine related, and petroleum related compounds includes reacting the contaminated water or soil with an oxidant, and one or more metals in elemental or alloy form until essentially all of the contaminants has been decomposed and the water or soil is essentially free of the contaminants.

There are many areas in the United States and in other countries of the world where soil or water is contaminated with one or more phenol related compounds. Phenol related compounds are compounds in which the hydrogens of phenol are replaced by other atoms or compounds. Well known examples are pentachlorophenol meta-chlorophenol and polychlorinated biphenyls. These compounds are toxic to humans to some degree and have been shown to cause cancer in animals. One effective method of remediation for contaminated soils, approved by the United States Environmental Protection Agency, is based on high temperature incineration. High temperature incineration, however, requires high energy consumption and is as costly as a result. Further, as incineration facilities are in fixed locations, soil to be remediated may need to be transported from a contaminated site to an incineration facility, and returned to the site, further increasing remediation cost.
There is a need for a soil remediation method which is not energy intensive, and which can be carried out on or close to a contaminated site.

Remediation of soil contaminated with organic compounds


An optical device which utilizes a photothermal optical effect to achieve switching or attenuation includes a waveguide defined by a waveguide core and a surrounding cladding, wherein the polymer waveguide core includes a region consisting of a photothermally responsive material having an absorption coefficient at a switch wavelength or attenuation wavelength that is higher than an absorption coefficient at a signal wavelength. Switching devices include an optical splitter circuit having a branch that includes the photothermally responsive material, and either a multiplexer for introducing light at the switch wavelength into the optical circuit or a light source focused at the photothermally responsive material. Attenuating devices include a Mach-Zehnder type interferometer having a branch that includes the photothermally responsive material and either a multiplexer for introducing light at the attenuation wavelength into the optical circuit or a light source focused at the photothermally responsive material.

1. Field of the Invention
This invention relates generally to optical devices, and more particularly to a thermorefractive switch or attenuator utilizing temperature dependence of the refractive index of a waveguide core to effect switching or attenuation in an optical device.
2. Technical Background
Optical switching devices are known which utilize materials in which the refractive index of a polymer waveguide material can be controlled through various phenomena such as by a second order nonlinear electrooptic effect, a third order nonlinear optical Kerr effect, a thermooptic effect, or an acoustooptic effect. Polymers have been used in thermooptic switches because of their large negative variations in the index of refraction as a function of temperature (dn/dT), which are typically about xe2x88x923xc3x9710xe2x88x924Kxe2x88x921. Stated differently, polymer materials are useful in the fabrication of thermooptic switches because a relatively small temperature change can effect a relatively large change in the refractive index of the polymer.
Typical polymer based thermooptic switches use thin film electrical strip heaters in contact with a planar polymer waveguide. These heaters effect a change in the refractive index thus causing thermooptic switching to occur. Fabrication of such devices requires metal electrode deposition techniques and integration of electronics into the planar optical devices which increase the complexity and cost of the device. A further disadvantage is that most electrically heated thermooptical devices are limited to switching speeds of about one to about two milliseconds due to thermal diffusion time lag.
It has been known that thermooptic effects can be induced in polymers by a photothermal phenomena in which light absorbed by the polymer is converted into heat which causes a change in refractive index. The change in temperature in a material due to absorption at steady state can be approximated by the following equation:       Δ              xe2x80x83            T    =            α                    xe2x80x83                  P                    xe2x80x83                          τ        c                    π                    xe2x80x83                          r        2                  ρ                    xe2x80x83                  C
where xcex1 is the absorption coefficient, P is the steady state power, xcfx84C is the characteristic decay time after the power has been turned off, r is the spot size radius of the area of the material which is irradiated with light having steady state power P, xcfx81 is the density of the material, and C is the heat capacity of the material. By exploiting photothermal effects, active switches can be developed by inducing local refractive index changes due to a finite amount of localized absorption of light by the polymer. A known device utilizing a photothermal effect for optical switching comprises a substrate of light absorbent material, means defining a plurality of holes of pre-selected size through the substrate, the holes being defined through the substrate, and a liquid material disposed within the holes. The liquid material has an index of refraction which is substantially temperature dependent over a selected temperature range of operation for the device. A disadvantage with this device is that it uses a liquid material which could potentially escape from the device, rendering the device inoperative. Accordingly, a solid state device is preferable.
An optical switch comprising a waveguide having a polymeric waveguide core including a region containing molecules which absorb energy from a light source and thereby heat the core and change the refractive index of the core are described in the patent literature. The device includes a waveguide having an input region, a Y-branch which splits light entering the input region into the two separate branches, and a coupling region. One of the two branches includes a means for changing the temperature to cause a change in refractive index, which in turn results in a phase shift between the light propagated through each of the two branches. When the light enters the coupling region a predetermined transfer, or switching, of light occurs from one leg to the other, with the amount of the transfer depending upon the phase change.
The invention provides an optical switching device which is capable of achieving submillisecond switching or attenuation for regions that are irradiated on the order of the size of a single mode waveguide mode field diameter.
In accordance with an aspect of this invention, an optical switch is provided which includes an optical splitter having a waveguide defined by a core and a surrounding cladding, wherein the waveguide includes an input leg, and first and second branch legs. The branch legs and the input leg are joined at a junction wherein light may be propagated from the input leg through each of the branch legs. The first branch leg includes at least a region comprised of a material having an absorption coefficient at a switch wavelength that is higher than an absorption coefficient at a signal wavelength.
In accordance with another aspect of the invention, a variable optical attenuator is provided. The variable attenuator includes a waveguide defined by a core and a surrounding cladding, wherein the core includes a first input waveguide section, a second waveguide section branching from the first waveguide section at a first junction, a third waveguide section branching from the first waveguide section at the first junction, and a fourth output waveguide section joined to the second and third waveguide sections at a second junction. The second waveguide section includes a region comprising a material which changes refractive index when exposed to light at an attenuation wavelength, but which is unresponsive to light at a signal wavelength.

Photothermal optical switch and variable attenuator


A combination cap and dispensing spout assembly for a carbonated beverage bottle. It is designed to stay on the beverage bottle until it is empty. It is pressed onto the original sealing cap of the carbonated beverage bottle and it is detachably snapped over the annular shoulder on the neck of the bottle. When it is desired to dispense some of the beverage, the bottle is turned upside down and the combination cap and dispensing spout assembly is rotated about 1/4-3/4 of a turn which allows the carbonated beverage to pour out of the tubular spout of the combination cap and dispensing spout assembly. The carbonated gas that has escaped from the liquid beverage cannot readily escape from the carbonated beverage bottle but instead rises into the space above the liquid beverage in the bottles upside down position. When the desired amount of carbonated beverage has been poured, the combination cap and dispensing spout assembly is rotated back to its original sealing position and the beverage bottle is returned to its upright position.

The invention relates to plastic carbonated beverage bottle and more specifically to a combination cap and dispensing spout assembly that is detachably secured to the top end of the carbonated beverage bottle.
Presently when a person wishes to pour some of the carbonated beverage from a plastic carbonated beverage bottle, the bottle is in its upright position and the original cap is unscrewed and taken off the top of a bottle. This allows some of the carbonated gases in the beverage to escape into the atmosphere prior to drinking from the bottle or pouring some of the carbonated beverage into a glass. The longer the top of the bottle remains uncovered, the more carbonated gas that is allowed to escape. With bottles in 1 and 2 liter sizes, it is rare that all of the carbonated beverage is consumed or poured at one time. Usually the cap is replaced on the top of the bottle. Every time the bottle cap is removed and more beverage consumed, additional carbonated gas escapes into the atmosphere and the beverage develops a flat taste.
It is an object of the invention to provide a novel combination cap and dispensing spout assembly that can be quickly and easily attached to and detached from the cap of a plastic carbonated beverage bottle.
It is also an object of the invention to provide a novel cap and dispensing spout assembly that is economical to manufacture and market.
It is another object of the invention to provide a novel cap and dispensing spout assembly that can be removed from the carbonated beverage bottle and reused on other carbonated beverage bottles.
It is an additional object of the invention to provide a novel combination cap and dispensing spout assembly that will minimize the amount of carbonated gas that is allowed to escape each time some of the carbonated beverage is poured from the bottle.

Combination cap and dispensing spout assembly


Pathogenic microorganisms such as Staphylococcus aureus are differentiated and identified by observing the selective inhibition of the microorganism which occurs when it is contacted with Alphazurine A dye.

The staphylococci are by far the commonest cause of skin infections such as boils, abscesses, carbuncles and similar suppurative processes in man. They are primarily significant as pathogens. They can be grown on culture media, such as agar or meat extract media, and the individual colonies are Circular with entire edges. The pathogenic forms, that is, those isolated from suppurative processes, usually are Staphylococcus aureus.
Staphylococci ferment mannitol with the formation of acid, the latter being detected by a decrease in pH of the media, as evidenced by color change of a pH indicator such as brom thymol blue, brom cresol purple, or phenol red.
Pathogenic staphylococci, that is, the Staphylococcus aureus, also cause clotting of decalcified blood plasma due to the production of staphylocoagulase, an active clotting agent. There is a high correlation between staphylococcal virulence for man and staphylocoagulase production. Coagulase-positive bacteria are usually virulent.
Plasma clotting (i.e., staphylocoagulase activity) can be demonstrated by mixing a bacterial culture with decalcified plasma, human or rabbit, incubating the plasma and observing clotting. The simple slide method is often used for qualitative purposes; the bacteria are suspended in a drop of plasma and observed on a slide for clumping.
In the treatment of wounds and similar skin lesions it is often desirable, and sometimes necessary, to identify the microorganisms in the wound or lesion in an agar medium and the microorganisms developed therein. It is therefore desirable to be able to identify Staphylococcus aureus promptly and accurately so that appropriate treatment can be instituted without delay. For this reason it is desirable to have a culture medium, and a sensitivity paper disc which inhibits the growth of Staphylococcus aureus and allows the rapid growth of most other microorganisms and thus allows rapid and accurate identification of coagulase positive organisms, mainly Staphylococcus aureus if present in the wound or lesion.
As discussed above, two of the most widely used tests for identifying staphylococci are the coagulase production test and the mannitol fermentation test. Most strains of Staphylococcus aureus isolated from human lesions are coagulase-positive and mannitol-positive. Coagulase-negative and mannitol-negative staphylococci, i.e. S. epidermidis and S. saprophyticus are most frequently considered to be less pathogenic. Positive reactions to both the coagulase production and mannitol fermentation tests are an indication of the pathogenicity of the staphylococci. Negative reactions to both tests indicate that the isolate has less clinical significance. Classical tests for coagulase production are performed routinely by the so-called "tube" method which measures free coagulase production or by the so-called "slide" technique which measures bound coagulase either on or in the cell wall of the organism. The tube method and the slide technique are described in the publications J. Bact. 41:431-440 (1941) and Medical Microbiology, T. Cruickshank, pages 137-138, published by Williams and Wilkins Company, 11th edition, 1965, respectively. In these tests, both rabbit plasma and human plasma have been used as the substrate.
Mannitol Salt Agar is used as a selective medium for the isolation of pathogenic staphylococci. This medium is descried in J. Bact. 50:201-203 (1945). Due to the presence of 7.5% sodium chloride therein, growth of most bacteria, other than staphylococci, is inhibited on this medium. When the medium is inoculated with a material containing staphylococci and incubated for a period of 36 hours at a temperature of 37.degree. C., mannitol-fermentation staphylococci grow luxuriantly, surrounded by yellow zones. In contrast, mannitol-non fermentation staphylococci produce small colonies, surrounded by red or purple zones. Positive identification of an unknown specimen as pathogenic can require as long as five days when conventional coagulase production and mannitol fermentation tests are employed.
A solid growth medium which is suitable for the visual identification of pathogenic staphylococci from initial cultures is described in the publication Am. J. Clin. Path. 32:192-194 (August 1959). Some measure of success has been achieved using this medium. However, it has been found that other bacteria which produce coagulase, grow on this medium.

Device and procedure for identifying pathogenic microorganisms


An improved magnetic head enables to reduce a crosstalk values without degrading head wear characteristic of the magnetic head when it is used as a pair of magnetic heads in a magnetic head assembly. The magnetic head has a first and second core sections, each containing at least a magnetic core. The first and second core sections forms a magnetic gap between the respective magnetic cores and a head-tape contact surface by being abutted at distal end surface thereof. The first core section has an approximately L-shaped configuration. The first core section has a head-tape contact core part for forming a part of the head-tape contact surface of the magnetic head and a straight core part extending in an opposite direction of the head-tape contact surface from the head-tape contact surface. The second core section has an approximately C-shape configuration to allow a winding to be provided around the second core section. Length of the head-tape contact core part is made longer than a length of the straight core part in a tape running direction.

1. Field of the Invention
The present invention relates to a magnetic head and a magnetic head assembly used for a high density recording/reproducing apparatus.
2. Description of the Related Art
Recently, in the high density magnetic recording and reproducing apparatus such as a video cassette tape recorder, there has been employed a multichannel system for simultaneously recording and reproducing information signals on and from a magnetic tape, wherein a plurality of magnetic heads are aligned parallel to each other in a tape running direction in a window provided in a rotary drum of the apparatus, and information signals are recorded and reproduced on or from a plurality of tracks on the magnetic tape by the plurality of magnetic heads by rotating the rotary drum together with the plurality of magnetic heads.
FIG. 1 is a partial front view showing a multichannel magnetic head assembly viewed from a head-tape contact surface side in the prior art.
Multichannel magnetic head assembly shown in FIG. 1, is employed, for instance, for simultaneously recording and reproducing the information signals on and from a magnetic tape (not shown). As shown in FIG. 1, both a recording magnetic head 1 having a magnetic gap 13 and a reproducing magnetic head 2 having a magnetic gap 23 are aligned parallel to each other on a head base 15 provided in a window 16 of a rotary drum 14 in such a manner that they are remote from each other at an interval D1 between the magnetic gaps 13, 23 thereof so as to allow the magnetic gaps 13, 23 to contact the magnetic tape upon a tape running operation.
Each of the recording and reproducing magnetic heads 1, 2 has a pair of magnetic core sections 11, 12, and 21, 22, and each of the pair of magnetic core sections 11, 12 (21, 22) is comprised of a pair of reinforcing members 12a, 12c (22a, 22c) and a magnetic core 12b (22b) interposed between the pair of reinforcing members 12a, 12c (22a, 22c) in a stacked manner.
The magnetic core section 11 of the recording head 1 has a length W1 which is the same as a length W1 of the magnetic core section 12 thereof, and the magnetic core section 12 of the reproducing head 2 has a length W1 which is the same as a length W1 of the magnetic core section 22 thereof as well.
The magnetic gap 13 of the recording magnetic head 1 is inclined at an angle .theta..sub.o to a line perpendicular to the head base 15 in a clockwise direction, and the magnetic gap 23 of the reproducing magnetic head 2 is inclined at an angle .theta..sub.o in a counterclockwise direction or the opposite direction to the magnetic gap 13.
In the simultaneous recording and reproducing system, there arises a crosstalk problem between the recording and reproducing magnetic heads 1, 2. To suppress a value of the crosstalk below a predetermined value, it is effective to extend the interval D1 between the magnetic gaps 13, 23 of the recording and reproducing magnetic heads 1, 2 or to provide a magnetic shielding member 17 between the recording and reproducing magnetic heads 1, 2.
The interval D1 is usually determined according to an electrical specification. Thus, it may be difficult to extend the interval D1. Even when it is possible to extend the interval D1, a too larger interval D1 causes a problem that the magnetic tape is slackened during the tape running operation. This slack of the magnetic tape prevents the recording and reproducing magnetic heads 1, 2 from securely contacting the magnetic tape, and causes a tape damage in a worst case.
As another countermeasure to suppress the value of crosstalk without extending the interval D1, it is effective to extend a distance between the magnetic core portions 12, 21 which are facing each other, by shortening the lengths W1 of the magnetic core portions 12, 21.
However, to shorten the lengths W1 of the magnetic core portions 12, 21 causes an other problem that a head wear characteristic of the recording and reproducing magnetic heads 1, 2 is degraded because of reduction of the head-tape contact areas thereof.

Magnetic head composed of a C-shaped core section and an inverse L-shaped core section, and a magnetic head assembly having a pair of the magnetic heads


A fuel gas channel is divided into first and second fuel gas channel units by a partition. The first fuel gas channel unit has a fuel gas inlet for supplying a fuel gas before consumption from a fuel gas supply passage to a fuel gas flow field, and the second fuel gas channel unit has an exhaust fuel gas diverging holes for diverging at least some of an exhaust fuel gas used at an anode from the fuel gas flow field. The second fuel gas channel unit is connected to the fuel gas supply passage through an exhaust fuel gas diverging passage.

Typically, a solid oxide fuel cell (SOFC) employs an electrolyte of ion-conductive oxide such as stabilized zirconia. The electrolyte is interposed between an anode and a cathode to form an electrolyte electrode assembly. The electrolyte electrode assembly is interposed between separators (bipolar plates). In use, predetermined numbers of the electrolyte electrode assemblies and the separators are stacked together to form a fuel cell stack.
In the fuel cell, a gas chiefly containing oxygen or the air (hereinafter also referred to as the "oxygen-containing gas") is supplied to the cathode, and a fuel gas such as a gas chiefly containing hydrogen (hereinafter also referred to as the "hydrogen-containing gas") or CO is supplied to the anode. The oxygen-containing gas and the fuel gas used in the reaction are disposed as an exhaust gas.
Since the exhaust gas contains the unconsumed fuel gas which has not been burned in the reaction, it is not economical to dispose all fuel gas including the unburned fuel gas as an exhaust gas. In this regard, as a technique for reducing the amount of the unburned fuel gas disposed of wastefully, for example, a fuel cell disclosed in Japanese Laid-Open Patent Publication No. 2002-151106 is known.
As shown in FIG. 11, the fuel cell is formed by stacking thin disks 1 and ring plate separators 2 alternately. The disk 1 is made of solid electrolyte material or the like. Ring plate path separators 3, 4 are formed on both surfaces of the disk 1.
A cell reaction passage 5a is formed between one surface of the disk 1 and one separator 2 through the path separator 3, and an air passage 5b is formed between the other surface of the disk 1 and the other separator 2 through the path separator 4.
A through hole 6 forming a fuel gas passage is provided at the center of the disk 1, and a plurality of combustion gas passages 7 are provided around the through hole 6. The through hole 6 is connected to the inlet of the cell reaction passage 5a through distribution inlet holes 8a, and the outlet of the cell reaction passage 5a is connected to the combustion gas passages 7 through discharge holes 8b.
According to the disclosure, fuel gas flows along the through hole 6, and then, the fuel gas is supplied into the cell reaction passage 5a through the respective distribution inlet holes 8a. The fuel gas makes a U-turn in the outer region of the disk 1, and flows into the combustion gas passages 7 from the discharge holes 8b. Then, the unburned fuel gas which is discharged to the combustion gas passages 7 is supplied into the through hole 6 of the fuel cell (not shown) connected to the combustion gas passages 7 on the downstream side, and used again for reaction. Thus, complete combustion of the fuel gas is achieved.
In the conventional technique, the through hole 6 is formed at the center of the disk 1, and combustion gas passages 7 are formed around the through hole 6. Therefore, the process of fabricating the disk 1 is considerably complicated, and special seal structure is required. Further, the shapes of the separator 2 and the path separators 3, 4 are complicated. Thus, the overall structure of the fuel cell is not economical.
Further, the fuel gas before consumption and the fuel gas after consumption are mixed together, and supplied to the cell reaction passage 5a. Therefore, density difference tends to occur in the fuel gas which is supplied to each of the cell reaction passages 5a in the stacking direction. Consequently, the power generation reaction occurs differently depending on the disk 1.


There is disclosed a microbicidal composition comprising as active ingredients:. (I) a dithiocarbonimide compound represented by the general formula: ##STR1## wherein Z represents CH group or nitrogen, R.sup.1 and R.sup.2 are the same or different and represent hydrogen, C.sub.1 -C.sub.6 alkyl group, halogen, C.sub.1 -C.sub.6 alkoxy group, C.sub.1 -C.sub.6 haloalkyl group or C.sub.1 -C.sub.6 haloalkoxy group, or R.sup.1 and R.sup.2 are taken together to form methylenedioxy group optionally substituted with fluorine, and. (II) at least one compound selected from the group consisting of azole microbicidal compound, cyclic amine microbicidal compound, N-(3,5-dichlorophenyl)imide microbicidal compound, anilinopyrimidine microbicidal compound, cyanopyrrole microbicidal compound, benzimidazole microbicidal compound, fluazinam, thiram and sulfur.

There have been hitherto known many microbicidal compositions. However, the kind of the disease damages to be controlled is very large and it is difficult to actually specify the kind of the disease damage, select the suitable microbicidal agent thereto and control the damage. In addition, the microbicidal agent has to deal with the new disease damages derived from the change in agricultural form. For these reasons, there is a need for a microbicidal composition having the high activity and wide microbicidal spectrum.


A dimeitylarnine silver bromo-iodide complex is used as a single source precursor for iodide incorporation in silver bromide crystals.

Silver halide emulsions are generally prepared using a reactive precipitation process; aqueous solutions of silver nitrate and alkali halides are reacted in the presence of gelatin. The composition of resultant product (silver halide emulsions) is tuned by varying the constituents of the alkali halide solution. For example, the precipitation of pure silver bromide emulsions is carried out using sodium bromide as the alkali halide, while silver bromide emulsions are precipitated using sodium bromide as the alkali halide. Appropriate addenda/dopants are generally introduced as aqueous solutions during the precipitation process, to generate silver halide emulsions of desired composition.
The important feature of all these processes is the bimolecular chemical reaction between (Ag+) ions and the appropriate anion(s) to generate the precipitating species. It is possible to vary the chemical and the structural composition of the product emulsion by varying the constituents of the reagent solutions, but the chemical reaction responsible for the generation of the desired silver halide emulsion is always the reaction between (Ag+) ions that are present in a solution or on the surface of the silver halide emulsion, and the appropriate anion(s).
From an operational point of view, generation of silver halide emulsions by this reactive precipitation process involves the addition of concentrated reagent solutions into a reactor under vigorous mixing conditions. The goal of the mixing process is to minimize the volume of the reactor that is exposed to the unreacted reagent solutions. However, even under ideal mixing conditions, the volume of the reactor that is exposed to the unreacted reagents is finite and relatively large.
In order to understand the reasons for the exposure of the reactor contents to unreacted reagents it is necessary to examine the mechanism of the mixing process. Mixing in emulsion precipitation processes is achieved by means of a rapidly spinning rotary agitator. The momentum generated by the rotary agitator results in the circulation of the fluid in the reactor. Appropriate baffling devices are used to randomize the fluid motion in the reactor, to achieve efficient mixing. It is important to recognize that efficient mixing requires rapid circulation of the fluid in thereafter. In a typical emulsion generation process, the reagent solutions are introduced into a region of the reactor that experiences good mixing. Consequently, the concentrated reagent solutions are introduced into a region of the reactor that experiences rapid circulation of the fluid in the reactor; i.e. the reagent introduction region in the reactor is exposed frequently to the contents of the reactor.
It is also important to recognize that efficient mixing is necessary at the reagent introduction region, in order to promote the reaction between the concentrated reagents. Because this (efficient) mixing process is carried out by rapid circulation of the reactor fluid through the reagent introduction region, the contents of the reactor are necessarily exposed to the concentrated reagents. From a kinetic view point, the extent of exposure of the reactor contents to the unreacted reagents would depend on the rate of dilution of the concentrated reagents relative to the rate of the chemical reaction between the concentrated reagents. Under ideal mixing conditions, the rate of dilution of the concentrated reagents is determined by the molecular/ionic diffusivity of the reactant species; which is still considerably smaller than the rate of the relevant chemical reactions. Hence, the extent of exposure of the reactor contents to the unreacted reagents can be significant even under ideal mixing conditions.
The unintentional exposure of the reactor contents to the unreacted reagents can have undesired effects on the emulsion crystals. For example, exposure of emulsion crystals to unreacted silver nitrate can result in the creation of fog centers in the crystals, while exposure of emulsion crystals to unreacted concentrated, potassium iodide can result in the destruction of grains. The grain destruction can be avoided by using dilute solutions of potassium iodide, solutions of iodide that also contain sodium bromide and long addition times. The disadvantages of this approach is the large volume of the reagents and the extension of the precipitation time (yield and productivity).
An alternative to the above approach is the use of silver iodide dissolved in an appropriate solvent as the source of iodide.
Halide introduction from concentrated solutions of silver halide complexes prepared from methylamineformamide and excess halide have been reported. However, methylamineformamide is exceedingly hazardous and the solvent has been documented as a teratogen (promotes deformity in embryos).

Preparation and use of a dimethylamine silver bromo-iodide complex as a single source precursor for iodide incorporation in silver bromide crystals


A digitizer is provided with a camera, a movable stage and a control device. The stage may be moved by first and second linear motors such that the digitizer can be used in non-stationary or vibrating environments. A bundle of fiber optics is used to constantly illuminate a patch of an image to be digitized. Also, a control device is provided between the camera and the first and second linear motors for controlling the camera and the positioning of the stage. Various sized images can easily be digitized while memory requirements are kept low and speed is kept high. This digitizer provides for an adaptive dynamic range as well as an improved contrast sensitivity. Also, a mechanism for correcting the effects of skew and keystoning is provided which enables collection of seamless mosaics.

1. Field of the Invention
The present invention relates to a digitizer for raster digitizing an image. An image here is a generic reference to an image, map, drawing, microfiche, microfilm or any other paper or film product. The digitizer can also capture either black and white or color media. The image will be mounted on a stage which is movable by linear motors and can be "patch" illuminated by using fiber optic bundles. The digitizer can capture data over a wide range of resolutions and includes an adaptive dynamic range feature.
2. Description of the Background Art
Various digitizers are known in the art. However, these digitizers are not suitable for use in nonstationary environments such as on a ship, land vehicle, aircraft or spacecraft. Therefore, use of these digitizers is limited.
Moreover, many conventional digitizers are rather large and are very sensitive. Therefore, these digitizers are susceptible to vibration and they create scan artifacts when digitizing an image.
Additionally, many conventional digitizers are not satisfactory when scanning a large image. Either the digitizers are not equipped to move the digitizing camera or stage holding the image over a large area or the digitizers will store an unnecessary amount of data concerning the entire image. Feature scanning cannot be accomplished by some conventional digitizers. Memory requirements for these conventional digitizers therefore increase and the speed at which an image can be digitized decreases.
Conventional digitizers also use gear or screw arrangements for moving the camera or stage upon which the image is mounted. Therefore, there is an initial friction between the gears which must be overcome before positioning of the stage can be carried out. This initial friction slows down the scanning process and reduces accuracy in the positioning of the image. Additionally, lead screws are difficult to extend to large sizes for accommodating larger media types. Longer lead screws tend to bend easily resulting in problems in both accuracy and reliability.
Conventional digitizers that utilize a two-dimensional array do not provide the capabilities to achieve truly seamless mosaics--namely, deskewing and keystoning adjustments. It is not possible mechanically to achieve perfect alignment between the axis of travel and the sensor axis. This misalignment must be computed and accounted for by deskewing the acquired image. Furthermore, mechanical limitations prevent light rays passing through the focal plane of the camera from being perfectly orthogonal to the film platen--resulting in trapezoidal-shaped pixels (referred to as keystoning in the art). When trapezoidal images are mosaiced in contiguous patches, the resultant image contains gaps and overlaps. Conventional digitizers do not account for keystoning, thereby limiting their ability to achieve truly seamless mosaics.
When digitizing an image, conventional digitizers are not concerned with providing uniform illumination to the image. Therefore, deviations in scanning the image can occur and the sensitivity of the camera is decreased. Additionally, variations in the amount of lighting cannot be accommodated nor can differences between each pixel of the digitizer be easily accommodated. Also, many conventional digitizers are unacceptable for digitizing X-rays and other images having dark regions. A better gray scale resolution in the digitizing art is therefore needed.
Accordingly, a need in the art exists for additional forms of digitizers which are suitable for use in nonstationary environments and which overcome the above-noted drawbacks of conventional digitizers.

Digitizer for raster digitizing an image


A system that detects temperature and current events in a power grid is provided. The system includes at least one sensor associated with an electric meter; a plurality of bus bars connected to the electric meter; at least one temperature sensor uniquely associated with each of the plurality of bus bars; and at least one current sensor uniquely associated with each of the plurality of bus bars. The system detects a plurality of temperatures and/or currents and compares the detected plurality of temperatures and/or currents to expected thresholds or threshold ranges for temperatures and/or currents in the system to provide a comparison result and determines if a notification related to temperature and/or current events in the system should be sent based on the comparison result.

Electric meters measure the amount of electric energy consumed by particular, load, for example, a residence, an office building, an apartment building or electrically powered equipment. Electric utilities use electric meters installed at customers' premises to measure electric energy delivered to their customers for, for example, billing purposes. This usage data may also be used for other reasons. Electric meters and the customers consuming the electricity may be part of a power grid.
A power grid is a system of producers and consumers of electricity. For example, the power grid may include power generators, the users of electricity, switches that control the electricity, and the system of substations, power lines, and transformers that deliver the electricity. More recently, power grids have become "smart." The main difference between the smart grid and conventional power grid is that the smart grid is based on demand follows supply while the conventional power grid is based on supply follows demand. In other words, the smart grid may include "smart devices", for example, smart electric meters, that can communicate with one another and allow needs of the grid to be predicted and supplied on the basis of these communications. The smart grid may be powered by both renewable energy sources and finite energy sources.
Electric meters can be subject to operating conditions that cause the meter itself to become excessively hot. Excessive heat can cause a meter to fail and may even damage the meter and other devices and systems on the power grid. Electric meters can also be subject to fault conditions during which a very large amount of current will flow through the meter. This situation can cause damage to the meter itself or the surrounding system. Excessive current can cause a meter to fail and may even damage the meter and other devices and systems on the power grid. Improved temperature sensing methods and improved methods for sensing current overload are desired.

Systems for detecting temperature and current events in a power grid and related methods


A liquid crystal display that is unsusceptible to the effect of a pixel potential during writing of data to a memory, allowing a large margin to be provided against variation in characteristics of transistors forming a pixel circuit, and a portable terminal having the liquid crystal display, serving to avoid variation in picture quality due to the variation in the transistor characteristics. In a pixel circuit including a memory circuit, separate paths are provided for writing image data from a signal line to the memory circuit via a data-write switch and for reading image data held in the memory circuit out into a liquid crystal cell unit via a data-read switch. Furthermore, image data are read via a data-read buffer. Accordingly, when image data is written to the memory, data held in the memory circuit is not affected by a pixel potential.

A liquid crystal display displays images by changing arrangement of liquid crystal molecules by applying and withdrawing an electric field and thereby controlling transmission/blocking of light. The liquid crystal display, in principle, does not require a large amount of power for driving, and it is a display device with a low power consumption, in which power consumption is maintained small. Thus, liquid crystal displays are widely used as output displays of portable terminals, particularly those mainly powered by batteries, such as cellular phones and PDAs (personal digital assistants).
In a liquid crystal display for this type of application, in order to allow use of a battery for a long period by a single charging, attempts have been made to reduce power consumption by lowering the driving voltage or by lowering the driving frequency. Furthermore, as a pixel structure that allows further reduction in power consumption, a liquid crystal display in which a memory is provided for each pixel is known (for example, refer to Japanese Unexamined Patent Application Publication No. 9-212140).
In such a liquid crystal display of a pixel structure in which a memory is provided for each pixel, with regard to a still picture, once image data is written to a memory unit of a pixel, it suffices to repeatedly drive the pixel for display using the image data stored in the memory of the pixel. Thus, signal lines need not be charged and discharged on each occasion, and in principle, the only electric power required is that for inverting polarity. This allows further reduction in power consumption.
In the liquid crystal display having the construction described above, the arrangement has hitherto been such that the same path is used for writing image data from a signal line to a memory unit of a pixel and for reading image data out of the memory into a liquid crystal cell unit at the pixel. Thus, when image data is written to the memory, since the liquid crystal cell unit is connected to a write line and the pixel capacitance is charged, the potential of the liquid crystal cell unit (hereinafter referred to as pixel potential) becomes unstable, affecting the write operation. Consequently, depending on characteristics of transistors forming the pixel circuit, data held in the memory might be modified by the pixel potential, causing considerable variation in picture quality due to the variation in the transistor characteristics.
The present invention has been made in view of the above problem, and an object thereof is to provide a liquid crystal display in which the effect of a pixel voltage during writing of data to a memory is removed, serving to provide a large margin against variation in characteristics of transistors forming a pixel circuit, and to provide a portable terminal having the liquid crystal display.

Liquid crystal display device and portable terminal device comprising it


A via for connecting metallization layers of chips bonded in a face-to-face configuration is provided, as well as methods of fabricating the via. The via may function as an interconnection of metallization layers in three-dimensional, stacked, integrated circuits, and may enable high density, low-resistance interconnection formation.

1. Field of Invention
The invention relates to three-dimensional (3D) integrated assemblies, and more particularly to three-dimensional (3D) integrated circuit assemblies including metallization interconnections.
2. Discussion of Related Art
Today's integrated circuits often include many (up to millions, or greater) integrated components and devices. However, for a given product, it sometimes is not possible, even with access to millions of components, to achieve on one integrated substrate (or integrated circuits, also know as chips) all of the circuitry or performance required. Thus, two or more substrates may be required. Also, fabrication process limitations sometimes dictate the use of two or more substrates for manufacturing different components. A major challenge then becomes the interconnection of the circuitry on multiple substrates. There may be hundreds of connections required between chips and it is necessary to keep connection resistance low and path lengths short to minimize inductive and capacitive effects, permitting high speed operation. While numerous interconnection arrangements and processes are known, many require special, complicated processes or expensive structures.
Additionally, as the number of components and devices on integrated circuits continues to increase, there exists an increasing number and complexity of on-chip wires used to connect the various components and devices, and to connect internal components and devices to external circuitry. These interconnections may be space-consuming, forcing the length of the interconnections to be longer and thus introducing more delay in signal propagation along these on-chip wires. Introducing additional wiring layers can result in a reduction of wiring lengths, but the formation or fabrication of such additional wiring layers may require additional or complicated processing steps. In addition, the cost of making interconnections is often a critical factor in determining the number of interconnections that may be used if a product is to sell.
Another way to reduce the length of interconnections (and the corresponding wiring delay, coupling capacitance between wires, loss mechanisms, and other unwanted wire parasitic) is to position the devices to be interconnected in a three-dimensional (3D) spatial arrangement. Part of the wire congestion in two-dimensional (2D) spatial arrangements comes from the inability to optimally place the components to be connected, and a 3D arrangement allows more possibilities for attaining optimal placement of components and devices. However, to attain the maximum advantage of wire shortening, the wires would have to be able to be directed vertically through vias between the 3D stacked circuits anywhere within the volume of the circuitry, and not just around the periphery of the stack. FIG. 1 illustrates an example of a 3D chip stack with vertical vias in the interior of the stack. The chip stack 100 includes substrates 110, 120, 130, and 140. Examples of vertical vias are shown as 112, 114, and 116.
A further advantage of 3D placement of components can be a reduction in the overall size of the package required to house these integrated circuits. Packages are often more expensive than the integrated circuits that they enclose, so housing more than one integrated circuit in a single package that would normally enclose only one integrated circuit produces a cost advantage, provided heat removal from the package does not exceed reasonable limits. One kind of multi-chip package would stack dies one upon another. For example, one existing method of packaging 3D integrated circuits consists of centering consecutively larger dies one upon another using wirebond or perimeter tape connections along the edges of the dies. Stacking by wire bonding is in current use today in multifunction cell phones and digital cameras. But this technique does not permit vertical vias within the body of the 3D circuit that can achieve optimal wire shortening between components within the stack, as the only vertical connections are around the periphery of the dies.
Another 3D configuration utilizes two substrates stacked in a face-to-face configuration, as illustrated in FIGS. 2A and 2B. The term face-to-face implies that the surfaces of the substrates that contain the devices and their contacts, called the faces, will be bonded facing each other. As shown, the two substrates 210 and 220 are aligned and bonded with their respective face surfaces facing each other. In such a configuration, a bridge via may be used to form an interconnection. Bridge vias are relatively expensive in chip area since they require the space of two vertical tunnels as well as the space (gap) between the tunnels to be dedicated to one vertical via signal connection. Since each tunnel and gap takes up surface area and creates some wire exclusion area, it is desirable to minimize this exclusion area for layout compactness.
Thus, a structure and method of forming compact integrated circuit assemblies and interconnections is needed. Preferably, this structure and method will be economical, will facilitate vertical connections within the body of the SD assembly and not just around the periphery, and will not require processing equipment beyond that employed for semiconductor monolithic wafer fabrication including those developed for existing Microelectromecanical Systems (MEMS). It is also desired that such structures and methods should support device interconnections that maintain low inductive, capacitive and resistive coupling between devices on different layers of the 3D die assembly.

Three-dimensional face-to-face integration assembly


In multicarrier transmission for multiplying transmit data individually by each code constituting orthogonal codes and transmitting each result of multiplication by a prescribed subcarrier, a plurality of different subcarriers are assigned exclusively to each user and each user performs multicarrier transmission of the transmit data by the subcarriers assigned. Further, a base station assigns a plurality of different subcarriers to each user exclusively, applies beam-forming processing on a per-user basis and performs multicarrier transmission of transmit data to each user by the subcarriers assigned.

This invention relates to a multicarrier CDMA transmission system and transmission method. More particularly, the invention relates to a multicarrier CDMA transmission system and transmission method for subjecting transmit data to a serial-to-parallel conversion, multiplying each symbol of the obtained parallel data individually by each code constituting orthogonal codes, and multicarrier-transmitting each result of multiplication by a prescribed subcarrier.
Multicarrier modulation schemes have become the focus of attention as next-generation mobile communication schemes. Using multicarrier modulation not only makes it possible to implement wideband, high-speed data transmission but also enables the effects of frequency-selective fading to be mitigated by narrowing the band of each subcarrier. Further, using orthogonal frequency division multiplexing not only makes it possible to raise the efficiency of frequency utilization but also enables the effects of inter-symbol interference to be eliminated by providing a guard interval for every OFDM symbol.
(a) in FIG. 10 is a diagram useful in describing a multicarrier transmission scheme. A serial/parallel converter 1 converts serial data to parallel data and inputs the parallel data to orthogonal modulators 3a to 3d via D/A converter 2a to 2d, respectively. In the Figure, the conversion is to parallel data comprising four symbols. Each symbol includes an in-phase component and a quadrature component. The orthogonal modulators 3a to 3d subject each of the symbols to orthogonal modulation by subcarriers having frequencies f1 to f4 illustrated in (b) of FIG. 10, a combiner 4 combines the orthogonally modulated signals and a transmitter (not shown) up-converts the combined signal to a high-frequency signal and then transmits the high-frequency signal. With the multicarrier transmission scheme, the frequencies are arranged, as shown at (b), in such a manner that the spectrums will not overlap in order to satisfy the orthogonality of the subcarriers.
In orthogonal frequency division multiplexing, frequency spacing is arranged so as to null the correlation between a modulation band signal transmitted by an nth subcarrier of a multicarrier transmission and a modulation band signal transmitted by an (n+1)th subcarrier. If we assume that a symbol (a complex baseband signal) transmitted by the nth subcarrier (center frequency: fn) is represented by zn (=an+jbn), then we may write modulation band signal sn(t)=Re[zn exp(j2πfn t)] (where Re represents the real part of the complex number). The requirement for the (n+1)th subcarrier to be orthogonal to the nth subcarrier is that the cross correlation between sn(t) and sn+1(t) be 0. If the frequency spacing between neighboring subcarriers is fd and the period of the symbol zn is T, then, in order for the cross correlation to become 0, it will suffice for fd=k/T (k=1, 2, . . . ) to hold and the minimum spacing will be fd=1/T. A multicarrier multiplexing scheme having frequency spacing is an orthogonal frequency division multiplexing scheme.
(a) of FIG. 11 is a diagram of the structure of a transmitting apparatus that relies upon the orthogonal frequency division multiplexing scheme. A serial/parallel converter 5 converts serial data to parallel data comprising a plurality of symbols (I+jQ, which is a complex number). An IDFT (Inverse Discrete Fourier Transform) 6, which is for the purpose of transmitting the symbols as subcarriers having a frequency spacing shown in (b) of FIG. 11, applies an inverse discrete Fourier transform to the frequency data to effect a conversion to time data, and inputs the real and imaginary parts to an orthogonal modulator 8 through D/A converter 7a, 7b. The orthogonal modulator 8 subjects the input data to orthogonal modulation, and a transmitter (not shown) up-converts the modulated signal to a high-frequency signal. In accordance with orthogonal frequency division multiplexing, a frequency placement of the kind shown in (b) of FIG. 11 becomes possible, thereby enabling an improvement in the efficiency with which frequency is utilized.
In recent years, there has been extensive research in multicarrier CDMA schemes (MC-CDMA) and application thereof to next-generation wideband mobile communications is being studied. With MC-CDMA, partitioning into a plurality of subcarriers is achieved by serial-to-parallel conversion of transmit data and spreading of orthogonal codes in the frequency domain. Owing to frequency-selective fading, subcarriers distanced by their frequency spacing experience independent fading on an individual basis. Accordingly, by causing code-spread subcarrier signals to be distributed along the frequency axis by frequency interleaving, a despread signal can acquire frequency-diversity gain.
An orthogonal frequency/code division multiple access (OFDM/CDMA) scheme, which is a combination of OFDM and MC-CDMA, also is being studied. This is a scheme in which a signal, which has been divided into subcarriers by MC-CDMA, is subjected to orthogonal frequency multiplexing to raise the efficiency of frequency utilization.
A CDMA (Code Division Multiple Access) scheme multiplies transmit data having a bit cycle Ts by spreading codes C1 to CN of chip frequency Tc using a multiplier 9, as shown in FIG. 12, modulates the result of multiplication and transmits the modulated signal. Owing to such multiplication, a 2/Ts narrow-band signal NM can be spread-spectrum modulated to a 2/Tc wideband signal DS and transmitted, as shown in FIG. 13. Here Ts/Tc is the spreading ratio and, in the illustrated example, is the code length N of the spreading code. In accordance with this CDMA transmission scheme, an advantage acquired is that an interference signal can be reduced to 1/N.
According to the principles of multicarrier CDMA, N-number of items of copy data are created from a single item of transmit data D, as shown in FIG. 14, the items of copy data are multiplied individually by respective ones of codes C1 to CN, which are spreading codes (orthogonal codes), using multipliers 91 to 9N, respectively, and products DC1 to DCN undergo multicarrier transmission by N-number of subcarriers of frequencies f1 to fN illustrated in (a) of FIG. 15. The foregoing relates to a case where a single item of symbol data undergoes multicarrier transmission. In actuality, however, as will be described later, transmit data is converted to parallel data of M symbols, the M-number of symbols are subjected to the processing shown in FIG. 14, and all results of M×N multiplications undergo multicarrier transmission using M×N subcarriers of frequencies f1 to fNM. Further, orthogonal frequency/code division multiple access can be achieved by using subcarriers having the frequency placement shown in (b) of FIG. 15.
FIG. 16 is a diagram illustrating the structure on the transmitting side of MC-CDMA. A data modulator 11 modulates transmit data and converts it to a complex baseband signal (symbol) having an in-phase component and a quadrature component. A time multiplexer 12 time-multiplexes the pilot of the complex symbol to the front of the transmit data. A serial/parallel converter 13 converts the input data to parallel data of M symbols, and each symbol is input to a spreader 14 upon being branched into N paths. The spreader 14 has M-number of multipliers 141 to 14M. The multipliers 141 to 14M multiply the branched symbols individually by codes C1, C2, . . . , CN constituting orthogonal codes and output the resulting signals. As a result, subcarrier signals S1 to SMN for multicarrier transmission by N×M subcarriers are output from the spreader 14. That is, the spreader 14 multiplies the symbols of every parallel sequence by the orthogonal codes, thereby performing spreading in the frequency direction. Codes that differ for every user are assigned as the orthogonal codes used in spreading.
In the case of a downlink (transmission by a base station), a code multiplexer 15 code-multiplexes the subcarrier signals generated as set forth above and the subcarriers of other users generated through a similar method. That is, for every subcarrier, the code multiplexer 15 combines the subcarrier signals of a plurality of users conforming to the subcarriers and outputs the result. A frequency interleaver 16 rearranges the code-multiplexed subcarriers by frequency interleaving, thereby distributing the subcarrier signals along the frequency axis, in order to obtain frequency-diversity gain. An IFFT (Inverse Fast Fourier Transform) unit 17 applies an IFFT to the subcarrier signals that enter in parallel, thereby effecting a conversion to an OFDM signal (a real-part signal and an imaginary-part signal) on the time axis. A guard-interval insertion unit 18 inserts a guard interval into the OFDM signal, an orthogonal modulator 19 applies orthogonal modulation to the OFDM signal into which the guard interval has been inserted, and a radio transmitter 20 up-converts the signal to a radio frequency, applies high-frequency amplification and transmits the resulting signal from an antenna.
The total number of subcarriers is (spreading ratio N)×(number M of parallel sequences). Further, since fading that differs from subcarrier to subcarrier is sustained on the propagation path, a pilot is time-multiplexed onto all subcarriers and it is so arranged that fading compensation can be performed subcarrier by subcarrier on the receiving side. The time-multiplexed pilot is a common pilot that all users employ in channel estimation. In case of uplink, the signals of each of the users are combined on the propagation path and received at a base station.
FIG. 17 is a diagram useful in describing a serial-to-parallel conversion. Here a common pilot P has been time-multiplexed to the front of transmit data. If the common pilot is 4×M symbols and the transmit data is 30×M symbols, then M symbols of the pilot will be output from the serial/parallel converter 13 as parallel data the first four times, and thereafter M symbols of the transmit data will be output from the serial/parallel converter 13 as parallel data 30 times. As a result, the pilot can be time-multiplexed into all subcarriers and transmitted. By using this pilot on the receiving side, fading compensation becomes possible on a per-subcarrier basis.
FIG. 18 is a diagram useful in describing insertion of a guard interval. If an IFFT output signal conforming to M symbols is taken as one unit, then guard-interval insertion signifies copying the tail-end portion of this symbol to the leading-end portion thereof. Inserting a guard interval GI makes it possible to eliminate the effects of inter-symbol interference ascribable to multipath.
FIG. 19 is a diagram showing structure on the receiving side of MC-CDMA. A radio receiver 21 subjects a received multicarrier signal to frequency conversion processing, and an orthogonal demodulator 22 subjects the receive signal to orthogonal demodulation processing. A timing-synchronization/guard-interval removal unit 23 establishes receive-signal timing synchronization, removes the guard interval GI from the receive signal and inputs the result to an FFT (Fast Fourier Transform) unit 24. The FFT unit 24 converts a signal in the time domain to N×M-number of subcarrier signals. A frequency deinterleaver 25 rearranges the subcarrier signals in an order opposite that on the transmitting side and outputs the signals in the order of the subcarrier frequencies.
After deinterleaving is carried out, a fading compensator 26 performs channel estimation on a per-subcarrier basis using the pilot time-multiplexed on the transmitting side and applies fading compensation. In the Figure, a channel estimation unit 26a1 is illustrated only in regard to one subcarrier. However, such a channel estimation unit is provided for every subcarrier. The channel estimation unit 26a1 estimates the influence exp(jφ) of fading on phase using the pilot signal, and a multiplier 26b1 multiplies the subcarrier signal of the transmit symbol by exp(−jφ) to compensate for fading. A despreader 27 has M-number of multipliers 271 to 27M. The multiplier 271 multiplies N-number of subcarriers individually by codes C1, C2, . . . , CN constituting orthogonal codes assigned to users and outputs the results. The other multipliers also execute similar processing. As a result, the fading-compensated signals are despread by spreading codes assigned to each of the users, and signals of desired users are extracted from the code-multiplexed signals by despreading.
Combiners 281 to 28M each add the N-number of results of multiplication that are output from respective ones of the multipliers 271 to 27M, thereby creating parallel data comprising M-number of symbols. A parallel/serial converter 29 converts this parallel data to serial data, and a data demodulator 30 demodulates the transmit data.
FIG. 20 is an explanatory view illustrating the state of MC-CDMA fading fluctuation in a downlink from a base station. A subcarrier signal of a prescribed user that has been spread along the frequency axis is code-multiplexed onto the subcarrier signal of another user and sustains fading that differs for every subcarrier on the propagation path. In the case of an outgoing call from a base station, however, a code-multiplexed subcarrier signal of a different user sustains the same fading FD12 on each subcarrier. As a result, if fading compensation is carried out using channel estimation information estimated for every carrier by means of the pilot symbol, fading sustained by each user can be compensated for simultaneously, as indicated by FD12′, orthogonality of the spreading codes of each of the users can be maintained and user signals will not interfere with one another. Accordingly, using a code having a high degree of orthogonality as the spreading code is extremely effective in an MC-CDMA scheme.
In the uplink, however, each user experiences different degrees of fading F1, F2 as shown in FIG. 21. Consequently, each subcarrier signal experiences independent fading user by user and orthogonality of the spreading code of each user is lost completely. For example, even if fading fluctuation F1 with respect to user 1 is compensated for by a fading compensator in the manner indicated at F1′, fading fluctuation F2 with respect to user 2 becomes as indicated at F2′. Accordingly, in a case where the MC-CDMA scheme for performing spreading in the frequency domain is applied to the uplink, a large deterioration in characteristics occurs.
Further, there are instances where a directional beam is emitted from a base station toward each user to transmit data. In such an instance it is necessary to provide an antenna array and carry out beam forming by causing a beam former to apply an array weight, which differs for every user, to the transmit data. FIG. 22 is a simple structural view of beam forming and illustrates an array antenna 31, a transmit beam former 32 for controlling the directivity of the beam by changing the array weight, and transmitters 331 to 33N for inputting transmit signals to antenna elements ATT1 to ATTN that construct the array antenna. The transmit beam former 32 controls the array weight in accordance with the direction of the user (mobile station), thereby transmitting the beam toward the user upon changing the magnitude and phase of the transmit signal applied to each antenna element.
In a case where a signal to which a weight that differs for every user has been applied is code-multiplexed in order to implement beam forming, each subcarrier will sustain fading that differs for every user, in a manner similar to that the uplink in FIG. 21, if this signal traverses a propagation path that experiences multipath fading. In particular, the larger the angular spread of multipath, the more the fading experienced by each user is different from and independent of that of other users. Even when beam forming is carried out, therefore, the orthogonality of spreading codes is lost and the characteristic deteriorates significantly. If the array weight of each user has been decided in such a manner that the beam will not be directed toward other users in this case, the interference component toward other users is suppressed and therefore the problem of loss of spreading-code orthogonality is eliminated. In actuality, however, the side lobes of the beam interfere with other users and, hence, the influence of deterioration of characteristics due to loss of orthogonality is great.
As shown in FIG. 23, there are also cases where a sector is divided into a plurality, e.g., three, of directional zones A1, A2, A3, and a beam having the same directivity is transmitted by being directed toward those mobile stations MS11 to MS12, MS21 to MS22, MS31 to MS32 present in the same directional zone. In the case of such beam forming, it is necessary to use an array weight that differs for every directional zone. However, if a signal to which a weight that differs for every directional zone is code-multiplexed and the code-multiplexed signal traverses a propagation path that experience multipath fading, then, in a manner similar to that of FIG. 21, each subcarrier will sustain fading that differs for every directional zone. In such case, fading sustained by users in different directional zones becomes independent, orthogonality of spreading codes is lost and characteristics deteriorate markedly. In this case also, if the array weight of each directional zone has been decided in such a manner that the beam will not be directed toward other directional zones, the interference component toward other users is suppressed and therefore the problem of loss of spreading-code orthogonality is eliminated. In actuality, however, side lobes SB of the beam BM interfere with other users, as shown in FIG. 23, and, hence, the influence of deterioration of characteristics due to loss of orthogonality is great.
Furthermore, in a case where each subcarrier has sustained fading that differs for every user, channel estimation must be performed using an individual pilot for each user in order to compensate for fading. With MC-CDMA, channel estimation must be carried out with regard to each subcarrier before despreading is performed. To separate an individual pilot of each user, there is a method of utilizing the pattern of a pilot and a method of shifting the position along the frequency and time axes of the pilot user by user to thereby effect separation. In either case, power allocated to individual channels decreases as the number of individual channels increases. (a) in FIG. 24 illustrates a case where a common pilot is used and (b) of FIG. 24 a case where individual pilots are used. The power of each individual pilot is one-fourth that of the common pilot. The greater the number of individual pilots, therefore, the greater the decline in the accuracy of channel estimation. Further, depending upon the placement and position of the pilot pattern, the channel of each subcarrier must be estimated as by finding channel information between pilots (channel estimation information) by interpolation.

Mulitcarrier CDMA transmission system and transmission method


A magneto-impedance element includes an amorphous wire having a spiral magnetic anisotropy. A dc-biased alternating current is supplied to the amorphous wire, whereby a voltage is produced between both ends of the amorphous wire. The amplitude of the voltage varies asymmetrically with a variation in an externally applied magnetic field. The magneto-impedance element is compact, and has a high sensitivity and a high response speed.

1. Field of the Invention
The present invention relates to a magneto-impedance element and a method of manufacturing the same. The magneto-impedance element serves as a magnetic head which is used for magnetic storage and magnetic recording in a computer, an information machine, etc., and is also used in control of drive apparatuses therefor. The magneto-impedance element also serves as a magnetic sensor head for detecting magnetic fields, currents, and the like.
The present invention also relates to a method and apparatus for magnetic sensing using a magneto-impedance element.
The present invention is applicable to many fields such as computers, information machines, information home appliances, mechatoronics, power electronics, medical electronics, industrial instrumentation such as non-destructive inspection, environmental measurement, and scientific measurement utilizing terrestrial field or rock magnetism.
Specifically, the present invention is applicable to all industrial fields in which Hall elements, magneto-resistance (MR) elements, and flux gate sensors are currently utilized, because the magneto-impedance element can be miniaturized to the same degree as Hall elements and MR elements, and the sensitivity in detecting magnetic fields is 100 fold or more compared to Hall elements and MR elements, i.e., comparable to that of flux gate sensors for detection of a uniform field. Therefore, in these areas, the present invention contributes to giving intelligence to measurement and control.
2. Description of the Related Art
The present inventors have proposed such a magneto-impedance element, as disclosed in Japanese Patent Application Laid-Open (kokai) No. 7-181239 entitled "Magneto-Impedance Effect Element".
The element disclosed in the publication is a slender magnetic element which is made of zero-magnetostriction amorphous wire or the like and whose circumferential permeability .mu. is high. When a high frequency current is caused to flow through the element, an AC voltage appears between both ends thereof, and the amplitude of the AC voltage sensitively varies in response to a magnetic field applied externally in the longitudinal direction of the element. In detail, when the circumferential permeability .mu. changes due to an external magnetic field, the impedance Z of the element changes due to a skin effect while maintaining the relationship .vertline.Z.vertline..infin..sqroot..mu. (the impedance decreases at a relatively low frequency, and increases at a high frequency). Therefore, the above-described element is called a "magneto-impedance element" or an MI element.
In the case where an amorphous wire of FeCoSiB which has been drawn and tension annealed so as to have a diameter of 30 .mu.m and a length of 1 mm is prepared as an MI element and a current of 5 mA having a frequency of 1 MHz is supplied to the MI element, the impedance .vertline.Z.vertline. of the MI element decreases by about 50% when an external magnetic field H.sub.ex of 5 Oe is applied (i.e., 10% decrease per Oe). Therefore, the MI element has a sensitivity about 100 times that of a conventional MR element (the resistance variation ratio of an MR element is about 0.1% per Oe), although the size is as small as the MR element. This means that the MI element is a micro magnetic element having a super high sensitivity. However, the impedance .vertline.Z.vertline. symmetrically varies depending on the absolute value of an external magnetic field H.sub.ex and does not depend on the sign of the external magnetic field H.sub.ex. For this reason, as in the case of an MR element, the MI element cannot form a linear magnetic sensor as is.
To overcome this problem, two MI elements are used and opposite bias magnetic fields are applied to these elements. By detecting the difference between the output voltages of the two elements, a magnetic field can be detected with high sensitivity. Therefore, a highly sensitive magnetic sensor can be obtained which has a resolution of 10.sub.-5 Oe and which has a sensitivity comparable to a flux gate sensor for a uniform magnetic field. Since the head length of the MI element can be shorted to about 1 mm, the MI element can detect a local magnetic field with considerably high sensitivity. When a resonant type multivibrator is formed by combining an MI element and a bipolar transistor or an FET, oscillation of 100 MHz-200 MHz can be easily obtained. Therefore, in the case of an amplitude modulation type magnetic sensor, a super high response speed is obtained because of a very high cut-off frequency of about 10 MHz. The cut-off frequency of a flux gate sensor is about 1 kHz.
As described above, the MI element is a basic element for constituting a micro magnetic sensor having a super high sensitivity and a super high response speed. However, the MI element has drawbacks which must be resolved. One of such drawbacks is a manner of applying bias magnetic fields. Conventionally, the following three methods have been used for applying a DC bias magnetic field:
(i) a coil is wound around a head, and a direct current is supplied to the coil; PA1 (ii) a permanent magnet is disposed in the vicinity of a head; and PA1 (iii) a coil is wound around a soft magnetic material having a rectangular BH characteristic, and a direct current is supplied to the coil, whereby a DC magnetic field generated from magnetic poles of the soft magnetic material is applied to the head.
However, these methods prevent the MI element from being manufactured in a micro size, and make the adjustment troublesome. Additionally adjustment of a long wire head having a length of a few tens of centimeters to detect a large current, is quite troublesome.

Asymmetrical magneto-impedance element having a thin magnetic wire with a spiral magnetic anisotropy

Research Development Corporation of Japan


An optical resolving reagent comprising at least one of compounds represented by the following formulae (1) and (2) (1) (2) (wherein R1 to R8 each represents hydrogen or C1-20 alkyl; R9 represents optionally substituted C1-20 alkyl, optionally substituted C1-20 alkenyl, formyl, or acyl; and R10 represents C1-6 alkyl; provided that the molecule represented by the formula (1) is of the cis configuration with respect to R9 and OR10); and a method of optically resolving with the optical resolving reagent an alcohol having an asymmetric carbon atom in the molecule and represented by the formula (3): (R11)(R12)(R13)COH (wherein R11, R12, and R13 each represents hydrogen or optionally substituted C1-20 alkyl, provided that at least one of R11, R12, and R13 is not hydrogen). The method of optical resolution is highly suitable for general purposes. By the method, a mixture of optical isomers of any of various alcohols can be optically resolved easily and industrially advantageously.

Many physiologically active substances such as pharmaceuticals, agricultural chemicals, perfumes, and sweeteners comprise a partial structure of alcohol having an asymmetric carbon atom. Optical isomers can be present in such a compound. However, there may be a significant difference in the degree of physiological activity among these optical isomers. Some isomers exhibit physiological activity quite different from others. Therefore, development of a method for separating an optical isomer mixture of an alcohol or a compound having a partial structure of alcohol (hereinafter both simply referred to as "alcohol") easily and surely has been desired.
However, the mixture can rarely be separated into two optical isomers without being influenced by an external optically active factor. Spontaneous resolution or the like rarely occurs. There are no general rules for separating the mixture. Accordingly, in almost all cases, it is highly difficult to assess whether or not an optical isomer mixture of an alcohol can be separated into optically active compounds. The mixture is not easily separated in almost all cases.
As an example of optically resolving an alcohol, Synlett., (6), 862 (2000), J. Org. Chem., 64, 2638 (1999), and the like describe a method comprising allowing one of optical isomers to remain as the alcohol and transforming the other optical isomer into an ester derivative in a natural optically active environment (for example, internal organs of animals containing an esterified enzyme or hydrolyzed enzyme). However, since such an enzyme does not have chemical stability, in particular, thermal stability, the enzyme cannot be used under high temperature conditions. Further, it is difficult for the enzyme to be generally and widely accepted due to its high cost and difficulty in procuring in a large amount.
Tetrahedron Lett., 35, 4397 (1994) reported an experiment in which an ester prepared by condensing a carboxylic acid having an asymmetric carbon atom with an alcohol was separated into individual diastereomers by silica gel column chromatography. In principle, this is optical resolution of an alcohol. However, since there are no general rules or principles for producing a highly separable diastereomer mixture, the method cannot be generally applied.
The present invention has been achieved in view of such a situation. Accordingly, the present invention provides a novel optical resolving reagent that can optically resolve an optical isomer mixture of an alcohol, having an asymmetric carbon atom in the molecule, easily and industrially advantageously, and a method for optically resolving an alcohol using the optical resolving reagent.

Method of optically resolving racemic alcohols with a bicyclooxaoctane or a bicycooxaoctene resolving reagents


An electrical filter apparatus for an electrostatic precipitator, wherein the filter apparatus is a T-type or pi-type filter electrically connected to a high voltage output of an electrostatic precipitator power supply and an electrostatic precipitator electrode. The T-type filter comprises a first inductor electrically connected to the high voltage output and a capacitor that is also electrically connected to ground. A second inductor is connected to the first inductor and the electrostatic precipitator electrode. In another embodiment, a two-stage inductor assembly is provided having a third inductor member defined by a plurality of turns of a continuous length of wire, and a fourth inductor member defined by a plurality of ferrite beads in end-to-end relationship.

a. Field of the Invention
The present invention relates to electrical filtering apparatuses used to filter the power input to an electrostatic precipitator.
b. Description of the Related Art
Electrostatic precipitators have taken on considerably greater importance in recent years, particularly in view of the increased emphasis upon maintaining a clean environment. That increased importance includes the need for more effective air pollution control by maintaining clean exhausts from industrial processes that involve either the combustion of fuels or the reaction or transformation of materials in chemical processing operations that result in the generation of particulate matter as a consequence of carrying out the process. The techniques and structural elements incorporated in modern electrostatic precipitators, particularly the electrical control apparatus for controlling the power provided for imparting a charge to the particulate matter to be collected, as well as the power provided to the collection surfaces, have been continually refined to more completely remove undesirable particulate materials from stack gases and also to provide longer useful operating life for the precipitator components. The stack gases in connection with the electrostatic precipitators are often necessary to meet environmental regulations include chemical process and cement plant exhaust gases, fossil fuel electric generating plant exhaust gases, and exhaust gases from steam generation boilers, such as those commonly associated with paper mills for processes such as paper web drying, where scrap "black liquor" from wood processing operations and other fossil fuels are often the fuel sources.
The theory behind the operation of an electrostatic precipitator involves the generation of a strong electrical field through which stack gases pass, so that the particulates carried by the stack gases can be electrically charged. By charging the particles electrically they can be separated from the gas stream and collected, and thereby not enter and pollute the atmosphere. The generation of such electrical fields requires electrical power supplies that can provide a high DC voltage to charge the particulate matter and thereby permit its collection. The existing systems are most often based upon AC corona theory, using a single phase transformer-rectifier (T/R) set to rectify AC power to DC power and provide a high DC potential between a charging electrode and a collection surface, usually a plate, to charge the particles by subjecting the stack gases to the maximum possible current without complete breakdown. That approach is believed to produce the maximum efficiency in effecting removal of such particles.
The emphasis in particulate removal is generally placed on increasing the current flow between a grid and a plate defining the electrostatic precipitator collection surfaces, to a current level that produces a maximum of sparking between the grid and the plate. In fact, some precipitators incorporate a grid structure that contains barbed wire such as DRAGON'S TEETH electrodes or special pointed rods, specifically to enhance such sparking. The sparking inside a precipitator is believed to be necessary as an indicator that the maximum possible current is being drawn, and therefore that the maximum possible ionization of the gases and particles is taking place. In fact, the practice of encouraging sparking is emphasized, even though it is known that sparking produces stresses upon the electrical components of the system, it causes increased precipitator maintenance because of the production of agglomerated particles, sometimes called "ash balls" or "klinkers," and it also causes difficulty in insuring that the rappers, which are devices that vibrate the precipitator plates to remove collected particles, are in fact operative and are removing collected particulate material.
A problem that results from operating an electrostatic precipitator as levels at which sparking occurs is the prevention of damaging arcing. An automatic controller for the input power to the T/R set must sense incipient arcing and immediately reduce the voltage on the precipitator collector plate, because any spark can quickly create an arc between the plate and the electrode, with a resultant high current flow. The high current flow can cause severe damage to the precipitator grid or plate. Additionally, arcing can cause the T/R set to fail, it can cause the controller to fail, or it can open the overcurrent protectors that are provided in the incoming power line. Any of those incidents will cause a section of the precipitator to be temporarily off-line, with the resultant undesirable passing of greater amounts of particulates into the atmosphere until the damage to the precipitator has been repaired. Repair can be a matter of minutes, or it can be weeks if the T/R set or controller has to be replaced.
Heretofore, the prevention of arcing has been attempted by providing complicated sensing and control circuits that add expense to the cost for an electrostatic precipitator. Examples of such circuits are shown in U.S. Pat. Nos. 4,290,003, which issued on Sep. 15, 1981, to Philip M. Lanese; 4,390,831, which issued on Jun. 28, 1983, to William Byrd et al.; 4,587,475, which issued on Oct. 19, 1993, to Gugliemo Liberati. However, the presently available circuits, although effective to some degree, still permit sparking and arcing to occur, thereby requiring more frequent maintenance of the precipitator to repair the damage that is caused by such sparking and arcing. Maintenance involves down time for the precipitator, and usually for the system in which the precipitator is installed, thereby increasing the cost for producing the product of the system in which the precipitator is employed.
In many electrostatic precipitators sulfur trioxide or ammonia, or both, must be injected into the gas stream in order to keep the opacity of the stack gases as low as possible. However, the use of such gases is undesirable because of their caustic nature, that over time causes damage to the precipitator and the stack, again necessitating repair and consequent down time of the process or equipment with which the precipitator is employed.
What is needed, therefore, is an electrical filter apparatus for electrostatic precipitators that provides higher output voltage, reduced voltage ripple, and lower high frequency energy, thereby increasing the ability of precipitators to collect particulate emissions from fossil-fueled boilers and reduce stack opacity.

Electrostatic precipitator power supply circuit having a T-filter and pi-filter