A multimode optical fibre communications system, and in particular to a system in which non-linearities in the propagation of the signal through a multimode optical communications channel degrade the signal presented to the receiver. The system includes an optical transmitter unit for connection to a multimode optical fibre transmission link. The transmitter unit has a data input for receiving an input data signal, a data signal processing circuit and a source of optical radiation. The data signal processing circuit is arranged to receive the input data signal from the data input and to provide a processed data signal to the source of optical radiation and the source of optical radiation is arranged to generate from this an optical signal for transmission by a multimode optical fibre. The data processing circuit is arranged to provide from the input data signal a non-inverted data signal and an inverted data signal, receive a control signal for controlling the generation of the processed data signal, apply a controllable delay in accordance with the control signal to at least one of the non-inverted and inverted data signals, and combine the non-inverted and inverted signals after the application of the controllable delay(s) and gain factor(s) to generate the processed data signal.

a. Field of the Invention
The present invention relates to a multimode optical fibre communications system, and in particular to an optical fibre communications system in which non-linearities in the propagation of the signal through a multimode optical communications channel degrade the signal presented to the receiver.
b. Related Art
An optical signal may be subject to numerous sources of noise and distortion, both in the generation of the signal and its transmission through an optical communications channel. Sources of noise in an optical transmitter or receiver include thermal noise and shot noise. A receiver section of the receiver may also use an avalanche photodiode for high sensitivity, but this will introduce avalanche photodiode noise. The generation of an optical signal will in general be subject to other sources of noise or drift. For example, the output power of a laser diode will be subject to slow drift as it heats up in use or from changes in ambient temperature. System distortion may be due to non-linear variations owing to the use of new or existing multimode optical fibre in an optical communications link. In a multimode optical fibre, different modes have different propagation velocities, which tends to disperse a pulse into adjacent pulses, thereby causing intersymbol interference (ISI). Pulse dispersion also occurs in single mode fibre, but to a lesser extent. Such effects will therefore tend to close an eye pattern and increase the measured bit error rate (BER) at the receiver.
Although changes owing to temperature drift can be compensated for quite easily, for example by temperature stabilisation of the laser source or with automatic gain control at the receiver, it is difficult to compensate for changes owing to pulse spreading in multimode optical fibres.
As a result, high-speed communications links, for example links operating at a data rate of at least 5 Gbit/s, have tended to use single mode optical fibre together with high precision optical fibre connectors. This has been the case even when such links are operating over short distances, such as in local area networks where links are typically of the order of 10 m to 100 m in length, or over medium distances, such as in metro networks where links are typically of the order of 1 km to 10 km in length. While such high-speed communications links provide reliable performance at a very low BER, for example 10−12, there is a need for comparable performance at greatly reduced cost, and in practice this requires the use of multimode optical fibre and cheaper connectors.
Therefore in recent years, multimode optical fibres have been used in communications links operating up to 10 Gbits/s over FDDI grade multimode fibre. With an 850 nm optical source, such links have been limited to about 30 m in length. With a 1310 nm optical source, such links have been limited to 80 m in length. It is, however, necessary in up to 90% of installed multimode optical fibre communications links to be able to transmit data over at least 300 m.
It has also been proposed to use an equaliser circuit at the receiver to compensate for intersymbol interference. Such an equaliser circuit receives as an input the output from a photodetector circuit and then generates from this at least two equaliser coefficients. A signal delay line also receives the output from the photodetector circuit. Tapped outputs from the delay line are each multiplied or otherwise combined with one of the equaliser coefficients, and then summed together to generate an equalised output signal. While this method can be effective in compensating for certain types of signal distortion, this adds additional cost to the receiver circuit and does not address the root cause of the problem of distortion due to pulse spreading in multimode optical fibre.
It is an object of the present invention to provide an optical communications system and a method of communicating an optical signal in such a system that addresses this problem.

Multimode optical fibre communication system

Avago Technologies General IP (Singapore) Pte. Ltd.


A method of recovering polychlorinated biphenyls from solution, which comprises a multi-step method of mixing and reacting an alkali metal or alkaline earth hydroxide in glycol solution with polychlorinated biphenyls in non-aqueous solvent to form biphenyl phenoxy-type anions, separating the glycol solution containing biphenyl phenoxy-type anions from the non-aqueous solvent, and separating the biphenyl phenoxy-type anions from the glycol solution.

This invention relates to the recovery of a hazardous class of chemicals referred to as polychlorinated biphenyls. More particularly, the invention concerns the recovery of polychlorinated biphenyls from solution by reaction and then extraction into glycol.
Compounds likely to accompany polychlorinated biphenyls in contaminated sites include polychlorinated alkylbiphenyls, polychlorinated polyalkylbiphenyls, polychlorinated triphenyls, polychlorinated oligo-phenyls, and polychlorinated polyphenyls, and metabolites of polychlorinated biphenyls, polychlorinated triphenyls, polychlorinated oligo-phenyls, and polychlorinated polyphenyls and others. The terms "PCB" and "polychlorinated biphenyls" as used herein are intended to be synonymous broad terms, including not only polychlorinated biphenyls themselves, but also related compounds which may accompany polychlorinated biphenyls in various processes or at contaminated sites.
PCB was known before the turn of the century. Although the useful industrial properties of mixtures obtained by chlorination of biphenyl were recognized early, PCB is relatively unreactive chemically. Therefore, from a purely chemical point of view, PCB is a rather uninteresting class of compounds. Limited attention was paid to them by the scientific community. However, in the mid 1960's, several publications noted the widespread occurrence of these compounds in the environment and the following events led to a dramatic upsurge of attention to PCB. It is now established that because of its lipid solubility (lipophilicity) and resistance to degradation, PCB accumulates in food chains and is distributed worldwide, like chlorinated pesticides such as DDT.
The literature on PCB is growing rapidly due to concern about PCB contamination of the environment. One result has been strict United States EPA standards on contamination. However, the removal of PCB from food chains is just one example of a broad need for methods of recovery of trace PCB contaminants from dilute aqueous and non-aqueous solution.
Prior art procedures for recovery of PCB include a variety of methods. One solution has been the reaction of PCB with hydroxylating agents. Unfortunately, such procedures are not always capable of effectively contacting and recovering PCB, especially when PCB is present only in trace quantities or in dilute solution. Furthermore, current PCB recovery strategies are expensive in terms of energy demand and time.
U.S. Pat. No. 4,619,744 teaches that heavy metals can be efficiently recovered from aqueous solutions by several novel methods involving interaction of the metals with water-soluble polymers. Unfortunately, the interactions between PCB and polymers are quite unlike those between heavy metals and polymers. Therefore, while a similar approach applicable to PCB was imagined at the time of the invention which led to U.S. Pat. No. 4,619,744, no such approach was found by the inventors. This resulted in part from the extreme unreactivity of PCB. A contributing factor was the hydrophobicity of PCB. Polymers which are soluble in non-aqueous solvents and have functional groups capable of reacting with PCB have been difficult to find.
Copending U.S. patent application Ser. No. 07/828,622 filed Jan. 31, 1992, discloses a method of recovering PCB from non-aqueous solution by mixing and reacting a soluble polymer with a PCB solution to form a precipitate reaction complex. The polymer has the formula ##STR1##

Recovering polychlorinated biphenyls from solution


A method of production of an α+β-type titanium alloy part for a motorcycle, car, or bicycle which has a high Young's modulus (rigidity) in the axial direction of the shaped product and a bolt, engine valve, or connecting rod made of an α+β-type titanium alloy and a method of production of the same, wherein an α+β-type titanium alloy is heated at the temperatures giving the β-single phase, then is uni-directionally hot rolled, the plate is machined so that a direction vertical to both the hot rolling direction and thickness direction (width direction) corresponds to the direction in which high rigidity is demanded in the finished part, that is, the axial direction of the bolt, engine valve, or connecting rod, and the X-ray diffraction intensities I(0002), I(10-10), and I(10-11), of the (0002) plane, (10-10) plane, and (10-11) plane of the titanium α-phase measured at the cross-sections vertical to the longitudinal axial direction of the parts satisfy I(0002)/[I(10-10)+I(10-11)]≧1.

A titanium alloy has a density of about 60% of steel and shows a high relative strength (=tensile strength/density), so is being used for machine parts for which lighter weight is demanded such as bolts, engine valves, and connecting rods.
As typical α+β-type titanium alloys which are used for such machine parts, Ti-6 mass % Al-4 mass % V (hereinafter referred to as "Ti-6Al-4V") and Ti-3 mass % Al-2.5 mass % V (hereinafter "Ti-3Al-2.5V") are used.
The shape of these machine parts is in general similar to that of rods which have long axes (except large ends and small ends of connecting rods). Force is likely to be applied in the long axis direction, so rigidity in the long axis direction is particularly demanded.
To raise the rigidity of a machine part, it is sufficient to increase the cross-sectional area of that part. However, if just increasing the cross-sectional area, the mass of the machine part increases. To raise the rigidity without increase in the mass of the machine part, it is necessary to increase the Young's modulus of the material itself.
The Young's modulus of titanium (at room temperature) is 88 to 113 GPa (9,000 to 11,500 kgf/mm2) which is as a small value as about a half that of a ferrous material, so titanium with high Young's modulus is highly needed.
Further, in addition to the above machine parts, in general, metallic materials with a high Young's modulus are desired for applications for machine parts of motorcycles, cars, and bicycles.
Titanium consists of the α-phase which is comprised of the hexagonal close-packed lattice (hereinafter "hcp") and the β-phase which is comprised of the body centered cubic lattice (hereinafter "bcc"). The Young's modulus of the α-phase is around 110 GPa, while that of the β-phase is around 90 GPa. The α-phase has about 20% higher Young's modulus than the β-phase.
For this reason, as explained above, α+β-type titanium alloys, mainly comprised of the α-phase, are being used for bolts, connecting rods, engine valves, etc. for which high rigidity is demanded.
As a method for increasing the Young's modulus of a titanium alloy, for example, there is the method of adding B (boron) to the titanium alloy and causing metal borides with high Young's moduli to be dispersed so as to raise the rigidity (for example, PLT 1).
In addition, there is the method of making a composite of high Young's modulus SiC fibers or carbon fibers with a titanium alloy (composite material).
For production of bolts, engine valves, and connecting rods made of a titanium alloy, round bars which are produced by hot working are being used as materials.
Bolts are produced by hot or cold forging or rolling, or cutting a round bar material.
The method of production of an engine valve includes an upset method consisting of heating an edge part of the round bar material to form an umbrella-like part and a hot extrusion method in which a round bar material is hot-extruded.
Connecting rods are produced by hot forging a round bar material.
In the above way, machine parts made of a titanium alloy are mainly being produced using round bars made of the titanium alloy as materials.
It is known that the hcp titanium α-phase has crystal orientation anisotropy in Young's modulus. The crystal orientation of the longitudinal direction of the round bar used as a material has a large influence on Young's modulus.
In a high strength titanium alloy columnar shape (round bar) which is produced by hot rolling and is the material for cold forging, crystal orientations in which c-axes of hcp are aligned in the circumferential direction or radial direction of the columnar shape are accumulated. Further, it is learned that the X-ray diffraction intensity from (0002) basal plane of the hcp measured on the T-cross-section of the columnar shape is extremely low and that the c-axes of the hcp are not accumulated in the longitudinal direction of the columnar shape (PLT 2).

α+beta-type titanium alloy part and method of production of same

NIPPON STEEL & SUMITOMO METAL CORPORATION


A continuous ink jet printhead has a nozzle bore formed from a thin membrane that comprises an overhang from a relief portion of the substrate. The thin membrane of thickness t overhangs a relief portion of the substrate with a dimension OH. The nozzle bore has a respective diameter dimension D. The dimensions are characterized in that OH greater than =xc2xd D; and wherein t less than =0.33D.

This invention generally relates to the field of digitally controlled printing devices, and in particular to liquid ink printheads in which a liquid drop is selected for printing by the asymmetrical application of heat to a jet of fluid.
Ink jet printing has become recognized as a prominent contender in the digitally controlled, electronic printing arena because, e.g., of its non-impact, low noise characteristics and system simplicity. For these reasons, ink jet printers have achieved commercial success for home and office use and other areas.
Ink jet printing mechanisms can be categorized as either continuous (CIJ) or Drop-on-Demand (DOD). U.S. Pat. No. 3,946,398, which issued to Kyser et al. in 1970, discloses a DOD ink jet printer which applies a high voltage to a piezoelectric crystal, causing the crystal to bend, applying pressure on an ink reservoir and jetting drops on demand. Piezoelectric DOD printers have achieved commercial success at image resolutions greater than 720 dpi for home and office printers. However, piezoelectric printing mechanisms usually require compiles high voltage drive circuitry and bulky piezoelectric crystal arrays, which are advantageous in regard to number of nozzles per unit length of printhead, as well as the length of the printhead. Typically, piezoelectric printheads contain at most a few hundred nozzles.
Great Britain Patent No. 2,007,162, which issued to Endo et al. in 1979, discloses an electrothermal drop-on-demand ink jet printer that applies a power pulse to a heater which is in thermal contact with water based ink in a nozzle. A small quantity of ink rapidly evaporates, forming a bubble, which causes a drop of ink to be ejected from small apertures along an edge of a heater substrate. This technology is known as thermal ink jet or bubble jet.
Thermal ink jet printing typically requires that the heater generates an energy impulse enough to heat the ink to a temperature near 400xc2x0 C. which causes a rapid formation of a bubble. The high temperatures needed with this device necessitate the use of special inks, complicates driver electronics, and precipitates deterioration of heater elements through cavitation and kogation. Kogation is the accumulation of ink combustion by-products that encrust the heater with debris. Such encrusted debris interferes with the thermal efficiency of the heater and thus shorten the operational life of the printhead. And, the high active power consumption of each heater prevents the manufacture of low cost, high speed and page wide printheads.
Continuous ink jet printing itself dates back to at least 1929. See U.S. Pat. No. 1,941,001 which issued to Hansell that year.
U.S. Pat. No. 3,373,437 which issued to Sweet et al. in March 1968, discloses an array of continuous ink jet nozzles wherein ink drops to be printed are selectively charged and deflected towards the recording medium. This technique is known as binary deflection continuous ink jet printing, and is used by several manufacturers, including Elmjet and Scitex.
U.S. Pat. No. 3,416,153, issued to Hertz et al. in December 1968. This patent discloses a method of achieving variable optical density of printed spots, in continuous ink jet printing. The electrostatic dispersion of a charged drop stream serves to modulate the number of droplets which pass-through a small aperture. This technique is used in ink jet printers manufactured by Iris.
U.S. Pat. No. 4,346,387, entitled METHOD AND APPARATUS FOR CONTROLLING THE ELECTRIC CHARGE ON DROPLETS AND INK JET RECORDER INCORPORATING THE SAME issued in the name of Carl H. Hertz on Aug. 24, 1982. This patent discloses a CIJ system for controlling the electrostatic charge on droplets. The droplets are formed by breaking up of a pressurized liquid stream, at a drop formation point located within an electrostatic charging tunnel, having an electrical field. Drop formation is effected at a point in the electrical field corresponding to whatever predetermined charge is desired. In addition to charging tunnels, deflection plates are used to actually deflect the drops. The Hertz system requires that the droplets produced by charged and then deflected into a gutter or onto the printing medium. The charging and deflection mechanisms are bulky and severely limit the number of nozzles per printhead.
Until recently, conventional continuous ink jet techniques all utilized, in one form or another, electrostatic charging tunnels that were placed close to the point where the drops are formed in the stream. In the tunnels, individual drops may be charged selectively. The selected drops are charged and deflected downstream by the presence of deflector plates that have a large potential difference between them. A gutter (sometimes referred to as a xe2x80x9ccatcherxe2x80x9d) is normally used to intercept the charged drops and establish a non-print mode, while the uncharged drops are free to strike the recording medium in a print mode as the ink stream is thereby deflected, between the xe2x80x9cnon-printxe2x80x9d mode and the xe2x80x9cprintxe2x80x9d mode.
Recently, a novel continuous ink jet printer system has been developed which renders the above-described electrostatic charging tunnels unnecessary. Additionally, it serves to better couple the functions of (1) droplet formation and (2) droplet deflection. That system is disclosed in the commonly assigned U.S. Pat. No. 6,079,821 entitled CONTINUOUS INK JET PRINTER WITH ASYMMETRIC HEATING DROP DEFLECTION filed in the names of James Chwalek, Dave Jeanmaire and Constantine Anagnostopoulos, the contents of which are incorporated herein by reference. This patent discloses an apparatus for controlling ink in a continuous ink jet printer. The apparatus comprises an ink delivery channel, a source of pressurized ink in communication with the ink delivery channel, and a nozzle having a bore which opens into the ink delivery channel, from which a continuous stream of ink flows. Periodic application of weak heat pulses to the stream by a heater causes the ink stream to break up into a plurality of droplets synchronously with the applied heat pulses and at a position spaced from the nozzle. The droplets are deflected by increased heat pulses from the heater (in the nozzle bore) which heater has a selectively actuated section, i.e. the section associated with only a portion of the nozzle bore. Selective actuation of a particular heater section, constitutes what has been termed an asymmetrical application of heat to the stream. Alternating the sections can, in turn, alternate the direction in which the asymmetrical heat is supplied and serves to thereby deflect ink drops, inter alia, between a xe2x80x9cprintxe2x80x9d direction (onto a recording medium) and a xe2x80x9cnon-printxe2x80x9d direction (back into a xe2x80x9ccatcherxe2x80x9d). The patent of Chwalek et al. thus provides a liquid printing system that affords significant improvements toward overcoming the prior art problems associated with the number of nozzles per printhead, printhead length, power usage and characteristics of useful inks.
Asymmetrically applied heat results in stream deflection, the magnitude of which depends on several factors, e.g. the geometric and thermal properties of the nozzles, the quantity of applied heat, the pressure applied to, and the physical, chemical and thermal properties of the ink. Although solvent-based (particularly alcohol-based) inks have quite a good deflection patterns, and achieve high image quantity in asymmetrically heated continuous ink jet printers, water-based inks are more problematic as disclosed in commonly assigned U.S. application Ser. No. 09/451,790 filed Dec. 1, 1999 in the names of Trauernicht et al. The water-based inks do not deflect as much, thus their operation is not robust. In order to improve the magnitude of the ink droplet deflection within continuous ink jet asymmetrically heated printing systems there is disclosed in commonly assigned U.S. application Ser. No. 09/470,638 filed Dec. 22, 1999 in the names of Delametter et al. a continuous ink jet printer having improved ink drop deflection, particularly for aqueous based inks, by providing enhanced lateral flow characteristics, by geometric obstruction within the ink delivery channel.
The invention to be described herein builds upon the work of Chwalek et al., and in accordance with certain embodiments of the invention is an alternate, simpler, design to that of Delametter et al. for constructing continuous ink jet printheads in a variety of materials that are low-cost to manufacture and preferably for printheads that can be made page wide. Alternatively, in accordance with other embodiments of the invention which make use of the improvements disclosed by Delametter et al. improved performance can be achieved.
Although the invention may be used with ink jet printheads that are not considered to be page wide printheads there remains a widely recognized need for improved ink jet printing systems, providing advantages for example, as to cost, size, speed, quality, reliability, small nozzle orifice size, small droplets size, low power usage, simplicity of construction in operation, durability and manufacturability. In this regard, there is a particular long-standing need for the capability to manufacture page wide, high-resolution ink jet printheads. As used herein, term xe2x80x9cpage-widexe2x80x9d refers to printheads of a minimum length of about four inches. High-resolution implies nozzle density, for each ink color, of a minimum of about 300 nozzles per inch to a maximum of about 2400 nozzles per inch.
To take full advantages of page wide printheads with regard to increased printing speed, they must contain a large number of nozzles. For example, a conventional scanning type printhead may have only a few hundred nozzles per ink color. A four inch page wide printhead, suitable for the printing of photographs, should have a few thousand nozzles. While a scanned printhead is slowed down by the need for mechanically moving it across the page, a page wide printhead is stationary and paper moves past it. The image can theoretically be printed in a single pass, thereby substantially increasing the printing speed.
It is therefore an object of the invention to provide an improved CIJ printhead and method of printing using same.
In accordance with a first aspect of the invention, there is provided a continuous ink jet printhead comprising a substrate including an ink delivery channel having ink under pressure in a relief portion formed in the substrate; a thin membrane that comprises an overhang from the relief portion of the substrate, the thin membrane being substantially thinner than a thickness of the substrate and the overhang extending from the relief portion with a dimension OH; a nozzle bore which opens into the ink delivery channel to establish a continuous flow of ink in a stream from the nozzle bore, the nozzle bore being formed in the thin membrane at the overhand and having an exit opening with a respective diameter dimension, D; a heater adjacent the nozzle bore, the heater adapted to produce asymmetric heating of the stream of ink to control direction of the stream between a print direction and a non-print direction; and the nozzle bore being characterized by a dimensional relationship wherein the overhang dimension OH is related to the diameter dimension of the exit opening so that OH greater than =xc2xd D; and wherein thickness t, of the membrane within which the nozzle bore is formed is related to the diameter dimension of the exit opening so that t less than =0.33D.
In accordance with a second aspect of the invention, there is provided a continuous ink jet printhead comprising a nozzle bore formed in a thin membrane that overhangs from a relief portion of a substrate, the thin membrane being of thickness t to define the thickness of the nozzle bore and the nozzle bore being spaced from the relief portion of the substrate with a dimension OH, the nozzle bore having a respective diameter dimension D and characterized in that OH greater than =xc2xd D; and wherein t less than =0.33D.
In accordance with a third aspect of the invention, there is provided a method of operating a continuous ink jet printhead comprising providing a substrate having plural ink delivery channels formed therein each channel terminating at a respective nozzle bore, each nozzle bore being formed in a thin membrane that comprises an overhang from a relief portion of the substrate, the thin membrane being substantially thinner than the thickness of the substrate and the overhang extending from the relief portion with a dimension OH, the nozzle bore having a respective diameter dimension D, and the thin membrane having a thickness t, and wherein the overhand dimension is related to the diameter dimension so that OH greater than =xc2xd D and wherein t less than =0.33D; moving ink under pressure from the ink delivery channels formed in the substrate to each of the nozzle bores to cause ink to flow continuously from the nozzle bores; and selectively effecting collection of certain ink droplets in collection devices associated with the nozzle bores so that ink droplets not collected by the collection devices form a predetermined image on a receiver sheet.
These and other objects, features and advantages of the present invention will become apparent to those skilled in the art upon reading of the following detailed description when taken in conjunction with the drawings wherein there are shown and described illustrative embodiments of the invention.

Continuous ink jet printhead with thin membrane nozzle plate


An image-setter and a scanning method are disclosed. The image setter includes at least two scanning surfaces, a media conveying system for conveying at least two light sensitive media to respective ones of the scanning surfaces, and an optical system for scanning substantially simultaneously the at least two light sensitive media on said respective scanning surfaces. The scanning method includes the steps of providing at least two scanning surfaces, conveying at least two light sensitive media to respective ones of said scanning surfaces, and employing an optical system for scanning substantially simultaneously the at least two light sensitive media on said respective scanning surfaces.

Image-setters which operate to scan a plurality of light sensitive media in order to plot digital information thereon are well known in the art. Conventional state of the art image-setters such as the Raystar, manufactured and sold by Scitex Corporation Ltd. of Herzlia, Israel, are designed to sequentially scan a plurality of light sensitive media such as films or plates.
As is well known in the art, four colors (Cyan, Magenta, Yellow and Black, known in the art as CMYB or CMYK) are usually used to produce a desired color. Since each color is printed separately, one has to produce four printing films or plates, one for each color CMYK. This is a time consuming process which requires that image-setters scan four times to produce the four films needed for printing one page.

Image-setter for multiple media exposure


A method for forming an interconnection of a semiconductor device, includes the steps of forming an insulating layer on a substrate on which a lower conductive layer is formed, selectively removing the insulating layer to form a first connecting hole and a second connecting hole for the pattern of an upper conductive layer, growing a first conductive material in the first connecting hole to form a buried plug and then depositing a second conductive material on the surface of the insulating layer to form a barrier layer, and depositing a third conductive material on the barrier layer to fill the second connecting hole and then patterning it to form an upper conductive layer.

The present invention relates to a method for forming an interconnection of a semiconductor device which improves resistance and reliability of the semiconductor device.
In general, an aluminum and an alloy thin film made thereof have a high electric conductivity and a good pattern formation by a dry etching. Further, their adhesion to a silicon oxide film is good and the cost is relatively low. Thus, they are widely used as a material for forming the interconnection of a semiconductor circuit.
However, as the number of integrations for forming an integrated circuit increases, the size of semiconductor devices is reduced and their interconnections become finer and multi-layers. Thus, in parts of the semiconductor devices having a certain topology or the inside of a contact or via hole, step coverage becomes an important issue.
For example, a connecting hole becomes narrower as the size of the semiconductor device decreases. The narrow connecting hole has an aspect ratio (hole height/hole width) of greater than one. Thus, using a conventional sputtering method to deposit an interconnection film in the narrow connecting hole results in an uneven deposition, which can degrade the operation of the connecting hole, for example, by causing an open circuit. Such a poor step coverage arising due to a shadow effect should be avoided.
Accordingly, instead of the conventional sputtering method, there is introduced a chemical vapor deposition (CVD) method which can provide a uniform thickness deposition and thus a good step coverage. For a chemical vapor deposition, a tungsten film is used. Thus, researches to forming a tungsten film using a low pressure chemical vapor deposition (LPCVD) method has been progressed.
However, the resistance of the tungsten interconnection film is twice more than that of the aluminum interconnection film, so that it is difficult to actually apply and pattern the tungsten film as an interconnection film. To overcome this problem, forming a plug in a connecting hole has been suggested.
As one of the methods for forming a plug, a tungsten film is selectively grown on a substrate exposed in a connecting hole by applying a selective chemical vapor deposition method. In another method, after forming a barrier metal film or an adhesive layer, a tungsten film is deposited on the entire surface and etched back to a desired thickness to form the plug.
However, in the above selective growth method, it is not easy to prevent the tungsten film from growing on an insulating film surrounding the connecting hole. In the etching back method, it is necessary to form a reliable barrier layer or adhesive layer in the connecting hole with the high aspect ratio. To do this, a collimator or a CVD method is used. However, in such a case, a minimum thickness sufficient to cause a nuclear generation of the tungsten in the bottom or sidewall of the connecting hole should be secured. Here, the top surface of the connecting hole is actually positioned higher than that of the plug since the depth of the connecting hole is variable according to the degree of planarization of the insulating film.
On the other hand, if a CVD method is used to form an aluminum interconnection, the step coverage can be improved. At the same time, peripheral processes related to the technology of forming an aluminum interconnection using the conventional sputtering method can be utilized.
Nevertheless, copper has a resistance lower than that of the aluminum and a good electromigration or stressmigration characteristic, thereby offering good reliability. Accordingly, methods for forming an copper interconnection using a sputtering or CVD method have been researched.
However, if a halogen compound useful for etching the aluminum were applied to copper, the operation temperature for the copper should be raised to about 500.degree. C. to obtain an applicable etch rate, since the vapor pressure of the halogen compound is low. Thus, instead of using a direct patterning through etching, a trench is formed in the shape of an interconnection pattern within a substrate to form the copper interconnection. Then the copper is deposited and etched back by a chemical mechanical polishing (CMP) method to form a buried conductive line. Alternatively, a method is suggested where a plug is selectively formed through a vertical growth using a lower conductive layer of a contact or via hole as a seed.
For forming a buried conductive line, a method has been suggested where a contact plug and a conductive line are self-aligned to uniformly maintain the contact area between the plug and the line. This forms a buried interconnection which has an improved contact resistance and integration capability.
Hereinafter, the conventional method for forming an interconnection of a semiconductor device will be described with reference to the attached drawing.
FIGS. 1a to 1f are cross-sectional views for illustrating the conventional method for forming an interconnection of a semiconductor device.
To begin with, as shown in FIG. 1a, an insulating layer 3 is formed on a substrate 1 on which a lower conductive layer 2 is formed.
As shown in FIG. 1b, a first photoresist 4 is coated on the insulating layer 3 and patterned so as to expose a portion of the lower conductive layer 2.
Using the patterned first photoresist 4 as a mask, the insulating layer 3 is selectively removed to form a connecting hole 5 for connecting the lower conductive layer 2 with an upper conductive layer which will be formed by the subsequent processes.
As shown in FIG. 1c, after removing the first photoresist 4, a second photoresist 6 is coated and patterned on the patterned insulating layer 3. Using the patterned second photoresist 6 as a mask, the insulating layer 3 is selectively removed to form a trench 7 for forming the upper conductive layer.
As shown in FIG. 1d, after removing the second photoresist 6, a barrier layer 8 made of a high refractory metal or a compound thereof is formed on the insulating layer 3 and the exposed lower conductive layer 2. Here, a titanium (Ti) can be used as the high refractory metal and a titanium nitride (TiN) can be used as its compound.
As shown in FIG. 1e, using a CVD or electrolytic deposition method, a conductive material such as copper is formed on the barrier layer 8, thereby forming an upper conductive layer 9 filling the connecting hole 5 and trench 7.
As shown in FIG. 1f, through a CMP (Chemical Mechanical Polishing) method, the upper conductive layer 9 is etched back until the surface of barrier layer 8 is exposed. This completes the conventional process of forming an interconnection of a semiconductor device. However, the aforementioned conventional method for forming an interconnection of a semiconductor device has many problems. For example, as interconnection becomes narrower and finer, the area of the connecting hole is reduced. This increase the amount of buried conductive material (having a high resistance) compare to the size of the connecting hole. As a result, the resistance of the buried interconnection increases and the reliability of the semiconductor device is deteriorated.

Method for forming interconnection of a semiconductor device


An internal combustion engine includes: a variable valve timing mechanism for changing a valve timing of at least one of an intake valve and an exhaust valve; a pressure for detecting an intake pressure and an exhaust pressure of the internal combustion engine that pulsate in association with the actions of the piston, the intake valve, and the exhaust valve; and controller for setting the valve timing based on a magnitude relationship between the intake pressure and the exhaust pressure detected by the pressure detector.

1. Field of the Invention
The invention relates to an internal combustion engine equipped with a control mechanism for controlling the timing of opening/closing the intake and exhaust valves and to a control method thereof.
2. Description of the Related Art
It is known that in the internal combustion engines, intake air and exhaust air pulsate in their respective pipes in association with the opening and closing actions of valves and the actions of pistons. Such intake pressure pulsation and exhaust pressure pulsation typically occur due to "reflection" of pressure changes caused by the intake valves and the exhaust valves, and such reflection can occur at a surge tank, a catalytic converter, etc., which are provided in the intake and exhaust passageways, more specifically at their openings or portions having an increased-sectional area. If the cycle of such intake and exhaust pulsation and the opening/closing timing of the intake and exhaust valves are synchronized, the inflow of fresh air from the intake pipe into the combustion chambers will be accelerated so as to improve the intake charge efficiency, and the efficiency of discharging burned gas from the combustion chambers into the exhaust pipe will be improved.
In association with this, there are known technologies in which intake pulsation and intake inertia effect are utilized to adjust the intake charge efficiency so as to increase the engine output. A known internal combustion engine that adopts such a technology includes a valve characteristic switching mechanism for controlling the cam operation angle by switching between two cams provided on an intake camshaft, a valve phase varying mechanism capable of changing the opening/closing timing of the intake valves to a retarded side and an advanced side by controlling the rotation phase of the intake camshaft, and intake pipe length changing mechanism for changing the characteristic frequency of pressure waves of intake pulsation and thereby adjusting the synchronization characteristic by changing the length of the intake pipe. In this internal combustion engine, intake pulsation and the intake inertia effect corresponding to the engine rotation speed can be achieved by changing the operation angle of the intake cams stepwise, and changing the phase of the intake cams (to the retarded or advanced side), and changing the period of intake pulsation stepwise. Thus, this internal combustion engine is advantageous in increasing the output. As a patent literature that describes the foregoing internal combustion engine technology, the following Patent Literature 1 is cited.
[Patent Literature 1]
Japanese Patent Application Laid-Open Publication No. 2000-328971
With regard to the exhaust side, a technology is known in which the exhaust pressure is detected and the opening/closing timing of the valves is accordingly set so as to improve the scavenging efficiency that depends upon exhaust pulsation, and therefore improve the intake charge efficiency. As a patent literature that describes such an internal combustion engine technology, the following Patent Literature 2 is cited.
[Patent Literature 2]
Japanese Patent Application Laid-Open Publication No. 11-22499
However, a problem with the above-described internal combustion engines is that it is difficult to always realize optimal valve timing. That is, even if the intake cam phase is set based on experimental values or design values so as to achieve an optimal valve timing in a certain operation region, that timing can not always be optimal in fact since the manner or characteristic of the above-stated intake pulsation changes due to aging changes or individual differences of the engine, etc. Furthermore, if cams are employed to open and close the valves, a correlation exists between the opening timing and the closing timing of the valves, so that the regions where the intake pulsation is sufficiently utilized during various states of engine operation are limited. That is, there are many regions where the dynamic effect of intake cannot be fully utilized due to insufficient response to variations of intake pulsation depending on the state of operation.

Internal combustion engine and valve timing control method


In a single lever mixing valve, having a sliding member sliding on a lever holder, for adjusting an amount and temperature of discharge water by rotating a disk actuating stem on an axis thereof or by operating a handle lever for inclining the disk actuating stem.

The present invention relates to a single lever mixing valve and more particularly to a single lever mixing valve having an improved operability.
The Single lever mixing valve is used a lot in a kitchen, a washing stand, and the like owing to its convenience.
The Single lever mixing valve is described below with reference to FIG. 13 showing a cartridge of the Single lever mixing valve.
A handle lever 8 is directly connected to a disk actuating stem 2 to transmit the motion of the handle lever 8 to a movable disk 4.
Cold and hot water enter the Single lever mixing valve from inlets port 6, pass through holes of a fixed disk 5, and are discharged from a outlet port 7 through a path shown with an arrow E.
A lever holder 1 is assembled inside the cartridge. The disk actuating stem 2 transmits a linear motion of the handle lever 8 for adjusting the amount of discharge water and a rotary motion of the handle lever 8 for adjusting the temperature of the discharge water to the movable valve 4. In correspondence to the linear motion and the rotary motion of the handle lever 8, the lever holder 1 slides on a sliding portion between it and the disk actuating stem 2, between it and the movable valve 4, and between it and a housing 3. The sliding portion is important because it affects the operability of the handle lever 8. In the conventional Single lever mixing valve, it is essential to apply a lubricant such as silicone grease to the sliding portion to allow smooth sliding of the handle lever 8 and the other members.
However, in recent years, people are more and more conscious of environmental hygiene. Thus, more and more users are unwilling to use the silicone grease although it is not harmful for the human body.
In the case where the single lever mixing valve is used in a particular environment, for example, a restaurant or the like and in case where it is used at high frequencies, the lubricant may decrease. With the decrease of the lubricant, an operator feels that the handle lever becomes heavy with time in its operation, squeaking sounds are generated during the operation thereof, and the operability thereof will deteriorate.
To apply the lubricant such as the grease to the sliding surface, it is necessary to produce the process of preparing the lubricant, applying the grease to the sliding portion, and maintaining grease-applying device. Consequently, the production efficiency will deteriorate.
The relationship between the handle lever 8 and the disk actuating stem 2 is described below with reference to FIG. 14. The handle lever 8 of the conventional single lever mixing valve is rotated on the disk actuating stem 2 square pillar-shaped or the like to rotate the movable valve 4 accommodated in the housing 3 to thereby adjust the amount of the discharge water, and the angle of the handle lever 8 with respect to a horizontal line is changed to incline the axis of the disk actuating stem 2 to thereby adjust the amount of discharge water by means of the movable valve.
The disk actuating stem 2 is fixed to the fit-in hole 8a formed in the vicinity of an end of the handle lever 8 opposite to the gripping portion thereof with a screw 8b, with the disk actuating stem 2 fitted in the fit-in hole 8a. A blindfolding plate-shaped cap 8c made of synthetic resin is installed on the screw 8b.
As shown in FIGS. 15 and 16, according to one mode of screwing the disk actuating stem 2 and the handle lever 8 to each other, a screw hole 2b is formed axially in the disk actuating stem 2 from an end surface thereof, and the screw 8b is inserted into a through-hole 8d formed in the vicinity of one end of the handle lever 8. According to another mode of screwing the disk actuating stem 2 and the handle lever 8 to each other, as shown in FIG. 16, the screw 8b is screwed into the screw hole 2b formed horizontally from one end surface of the handle lever 8, and the front end of the screw 8b is pressed against the disk actuating stem 2 to fix the disk actuating stem to the handle lever 8.
However, in any of the above-described conventional single lever mixing valves, the handle lever and the disk actuating stem are fixed to each other with a screw to which a loosening prevention agent (commercial name: Lock-tight) applied to increase the friction resistance of the surface of the screw. Thus, a handle lever-installing operation takes time and labor.
Further, in the handle lever-installing operation, screw-tightening degrees are apt to be nonuniform. Thus, produced single lever mixing valves are liable to have nonuniform tolerances.
Further, during the use of the single lever mixing valve, there is a possibility that the loosening prevention agent penetrates into a sliding portion between mixing valves of the single lever mixing valve little by little. If the loosening prevention agent remains on the sliding portion, the sliding portion is worn. Consequently, a liquid such as water passing through single lever mixing valve is easy to leak.
Furthermore, the action of the loosening prevention agent of preventing loosening of the screw deteriorates gradually with time. Thus, the long-time use of the single lever mixing valve causes the screw to be loose and makes it difficult to operate the handle lever securely.
Consequently, an operator feels that the handle lever becomes heavy with time in its operation, squeaking sounds are generated during the operation thereof, and the operability thereof will deteriorate.
The present invention has been made to overcome the above-described problems. Accordingly, it is an object of the present invention to provide a single lever mixing valve eliminating application of a lubricant to sliding portion in consideration of environmental hygiene, allowing an operator to feel that the handle lever is lightweight in its operation even though the lubricant is not applied to the sliding portion, preventing a torque from fluctuating with time, and allowing the handle lever to be operated easily.
It is another object of the present invention to provide a single lever mixing valve having a simple handle lever-fixing construction eliminating the need for application of a loosening prevention agent. It is still another object of the present invention to provide a single lever mixing valve allowing the handle lever to be operated lightly and securely even though the single lever mixing valve is used for a long time.
More specifically, in the single lever mixing valve, a handle lever-installing operation can be accomplished in a possible simplest degree and assembled without taking much time and labor. It is still another object of the present invention to provide a single lever mixing valve which allows the handle lever to be Installed securely, has a uniform tolerance, prevents the handle lever from being loose or causing no troubles even though the single lever mixing valve is used over as many as 200,000 cycles, and prevents a movable disk and a fixed disk from being damaged easily.
To achieve the object, there is provided a single lever mixing valve comprising a sliding member sliding on a lever holder, and a disk actuating stem supported with the lever holder, for adjusting an amount and temperature of discharge water by inclining or rotating on an axis thereof the disk actuating stem to be operated by a handle lever. One sliding surface of at least one of the sliding portions in which the lever holder and the sliding member slide on each other is formed of a polyamide resinous composition.
The polyamide resinous composition contains polyolefin resin essentially or is aromatic polyamide resin. The aromatic polyamide resin in the present invention has aromatic rings in its chemical structure of polymeric main chain.
One sliding surface or both sliding surfaces of at least one of the sliding portions are formed of the polyamide resinous composition. Thus, the sliding surface has favorable sliding performance, Consequently, the torque of the handle lever hardly fluctuates with time during the operation of the handle lever even though the lubricant is not applied to the sliding portions. Thus, it is possible to provide the greaseless single lever mixing valve.
According to another aspect of the present invention, there is provided a single lever mixing valve for adjusting an amount and temperature of discharge water by rotating a disk actuating stem, on an axis thereof or by operating a handle lever for inclining the axis of the disk actuating stem. A fit-in hole is so formed on the handle lever that the disk actuating stem is loosely fitted therein, with a gap formed between a side surface of the disk actuating stem and a gap-defining inner surface of the handle lever. A spacer so sized as to close the gap is provided. A spacer insertion hole is formed in the handle lever such that the spacer insertion hole is open on an outer surface of the handle lever. The spacer is inserted into the spacer insertion hole to fix the disk actuating stem fitted in the spacer insertion hole.
In the single lever mixing valve, it is possible to adopt the construction in which the spacer insertion hole is formed in penetration through the handle lever in the range from the gap to the outer surface of the handle lever.
In the single lever mixing valve, it is possible to adopt the construction in which the spacer insertion hole is wedge-shaped such that the insertion hole becomes gradually smaller toward an inner end along the gap.
In the single lever mixing valve having the above described construction, the disk actuating stem is loosely fitted in the fit-in hole of the handle lever made of resin, with a gap formed between the side surface of the disk actuating stem and the gap-defining inner surface of the handle lever. Therefore, it is simple and speedy to fit the disk actuating stem in the handle lever. There is no gap left by merely inserting the spacer into the spacer insertion hole on the outer surface of the handle lever. Thus, the disk actuating system can be fixed to the fit-in hole, with both in close contact with each other. This construction eliminates the need for the provision of a screwing construction and for the application of a loosening prevention agent.
Further, a certain fixing force can be obtained owing to the frictional engagement between the fit-in hole and the disk actuating stem. Thus, the single lever mixing valve has a uniform tolerance.
In the above-described construction in which the spacer insertion hole is formed in penetration through the handle lever in the range from the gap to the outer surface of the handle lever, the spacer is pressed against the side surface of the disk actuating stem and allows the disk actuating stem and the handle lever to closely contact each other.
In the above-described construction in which the spacer insertion hole is wedge-shaped such that the insertion hole becomes gradually smaller toward the inner end along the gap, the spacer inserted into the spacer insertion hole expands the narrow portion of the inside of the spacer insertion hole. Consequently, the fit-in hole formed in the handle lever so deforms that the gap decreases. When the fit-in hole has made a deformation to the maximum, the side surface of the fit-in hole and that of the disk actuating stem are pressed against each other.
It is preferable to adopt the construction in which a concave portion or a convex portion which fits in the concave portion is formed on a side surface of the fit-in hole or the disk actuating stem to prevent the disk actuating stem from sliding axially. This construction fixes the handle lever and the disk actuating stem to each other securely.
In the single lever mixing valve having such a construction, the fit-in hole and the disk actuating system are so locked to each other with the convex portion and the concave portion that the disk actuating stem is incapable of moving axially. Thus, the slip-off of the handle lever is securely prevented.
In the single lever mixing valve having any one of the above described constructions, a linear projection is formed on a side surface of the spacer or a side surface of the spacer insertion hole along a spacer insertion direction.
In the construction, when the spacer is inserted into the spacer insertion hole, both members contact each other through the linear projection. That is, both members contact each other not entirely. Thus, both members contact each other in a smaller area when and after the spacer is inserted into the spacer insertion hole. Therefore, the friction resistance is low, which allows a smooth operation of inserting the spacer into the spacer insertion hole and removing it therefrom to replace component parts.

Abstract: A fit-in hole is so formed on the handle lever that the disk actuating stem is loosely fitted therein, with a gap formed between a side surfaced of the disk actuating stem and a gap-defining inner surface of the handle lever; a spacer so sized as to close the gap is provided; a spacer insertion hole is formed in the handle lever such that the spacer insertion hole is open on an outer surface of the handle lever; and the spacer is inserted into the spacer insertion hole to fix the disk actuating stem fitted in the spacer insertion hole.


A wiring according to the present invention is made of a chromium layer and a chromium nitride layer. To make the wiring, a layer of chromium is deposited on a substrate, and then a layer of chromium nitride is deposited. A layer of photoresist is covered on the layer of chromium nitride and patterned, the layers of chromium and chromium nitride are wet etched in sequence using the photoresist pattern as a mask. Since the layer of chromium nitride is etched more quickly than the layer of chromium, the layer of photoresist and the layer of chromium are separated from each other and the chromium layer is isotropically etched to form a pattern having an edge with a gentle slope.

(a) Field of the Invention
The present invention relates to wiring using chromium nitride, methods of fabrication therefor, liquid crystal display panels using the same wiring and methods of fabrication therefor.
(b) Description of the Related Art
Aluminum or chromium is used for wiring of liquid crystal display (LCD) panels, i.e. gate lines or data lines. Chromium is widely used for data lines because of the better ohmic contact with amorphous silicon and indium tin oxide than aluminum though it has relatively high resistance.
An example of the conventional LCD panel and the manufacturing method is described in U.S. application Ser. No. 08/754644.
Aluminum or aluminum alloy is used to make gate lines, but aluminum or its alloy reacts with the ITO (indium tin oxide) layer. So, gate lines are made of a double layer of aluminum and chromium instead of a single layer of aluminum, and the upper layer of aluminum is removed in the gate pad region. But, the additional step of removing the layer of aluminum complicates the process. Moreover, the surface of the chromium layer is contaminated when dry etching, and the surface of the chromium tends to impair the steps of forming the passivation layer and forming the contact holes.

Wiring using chromium nitride and methods of fabrication therefor, liquid crystal display panels using the same wiring and methods of fabrication therefor


Data storage devices are provided. A data storage device includes a memory transistor on a substrate and a data storage structure electrically connected to the memory transistor. The data storage structure includes a magnetic tunnel junction pattern and a top electrode on the magnetic tunnel junction pattern. The top electrode includes a first top electrode and a second top electrode on the first top electrode, and the first and second top electrodes include the same metal nitride. The first top electrode includes first crystal grains of the metal nitride, and the second top electrode includes second crystal grains of the metal nitride. In a section of the top electrode, the number of the first crystal grains per a unit length is greater than the number of the second crystal grains per the unit length.

The present disclosure relates to semiconductor devices and methods of fabricating the same and, in particular, to data storage devices including a magnetic tunnel junction and methods of fabricating the same. As electronic devices with high speed and/or low power consumption properties are needed, there is an increasing demand for semiconductor memory devices with faster operating speeds and/or lower operating voltages. Magnetic memory devices have been proposed to satisfy such a demand. For example, magnetic memory devices can provide technical advantages, such as high speed and/or non-volatility, and thus magnetic memory devices are emerging as next-generation memory devices.
A magnetic memory device typically includes a magnetic tunnel junction (MTJ). The MTJ includes two magnetic layers and an insulating layer interposed therebetween. Resistance of the MTJ varies depending on magnetization directions of the magnetic layers. For example, the resistance of the MTJ is higher when magnetization directions of the magnetic layers are anti-parallel to each other than when they are parallel to each other. Such a difference in resistance can be used for data storing operations of the magnetic memory device. However, more research may still be performed to help satisfy demand for magnetic memory devices with higher integration density and lower power consumption properties.

This patent is subject to a terminal disclaimer.

Data storage devices including a first top electrode and a different second top electrode thereon


The present invention provides a method for providing anesthesia using a composition comprising olanzapine and one or more opioids.

This invention relates to a therapeutic combination of compounds to provide anesthetic activity.
Surprisingly, we have discovered that olanzapine can be particularly useful as an anesthetic when used in combination with one or more opioid compounds. More specifically, the invention provides a method of providing anesthesia in a mammal using olanzapine in combination with an opioid to provide such anesthetic effect.
There are opioid compounds known in the literature and to the skilled artisan. see Merck Manual, 16th Ed. (1992) p. 1409.
One of the key advantages possible with the method claimed herein relates to significantly reduced side effects associated with opioid compounds. The presently claimed combination provides benefits associated with post-surgical emergence from anestesia. Opioids are associated with undesired post-surgical side effects, which can be significantly alleviated using the combination claimed herein. With the current propensity toward outpatient surgery, the benefical properties of this combination could provide a valuable benefit for the patient. Further, the composition claimed herein can be especially useful during the presurgical preparation period, particularly if the patient is in pain.
It is known that olanzapine can provide antipsychotic activity. Olanzapine is a known compound and described in U.S. Pat. No. 5,229,382 as being useful for the treatment of schizophrenia, schizophreniform disorder, acute mania, mild anxiety states, and psychosis. U.S. Pat. No. 5,229,382 is herein incorporated by reference in its entirety. Surprisingly, and in accordance with this invention, Applicants have discovered that olanzapine can be useful as an anesthetic when administered with one or more opioids. An olanzapine:opioid composition could address a long felt need for a safe and effective anesthetic with fewer side effects.


An endoscopic apparatus includes an ultrasonic vibrator, a diffraction grating, an electrical energy generator, a detector, a determination unit, a controller. The diffraction grating converts the ultrasonic vibration into a surface acoustic wave propagating on a surface of the transparent member. The detector detects reflected electrical energy reflected from the energy supply system. The determination unit determines whether the electrical energy suitable to drive the ultrasonic vibrator has been supplied to the ultrasonic vibrator based on the reflected electrical energy detected by the detector. The controller controls the electrical energy output from the signal generator based on a determination result of the determination unit.

1. Field of the Invention
The present invention relates to an endoscopic apparatus in which a diffraction grating is arranged on a transparent member such as a cover glass provided at the distal end of the endoscopic apparatus, and contamination on the transparent member is removed by applying ultrasonic vibration to the transparent member by means of a piezoelectric vibrator, thereby propagating a surface acoustic wave across the transparent member, and an operation control method for the same.
2. Description of the Related Art
When the distal end of an endoscopic apparatus (hereinafter, simply referred to as the distal end) is inserted into a body cavity during surgery, contamination such as body fluids or droplets produced by the use of an RF knife may adhere to a cover glass provided at the distal end. To remove this contamination, there are well-known techniques of imparting the vibrations of an ultrasonic vibrator to the cover glass to cause a surface acoustic wave to propagate. Such a technique is taught in Jpn. Pat. Appln. KOKAI Publication No. 2006-055275, for example, which discloses that a cover glass is provided at a distal end, and ultrasonic vibration is induced in the cover glass by imparting oscillations from an ultrasonic vibrator, thereby removing contamination from the cover glass.
In the technique of removing contamination from a cover glass by using a surface acoustic wave obtained by the application of ultrasonic vibration, an ultrasonic vibrator must be driven at high power in the range of several watts to several tens of watts. In a conventional endoscopic apparatus using a piezoelectric vibrator as the ultrasonic vibrator, high power is supplied to the piezoelectric vibrator without taking into account the driving state of the piezoelectric vibrator or the state of transmission of the surface acoustic wave.

Endoscopic apparatus and operation control method for the same


An extendable tool having an internal drive assembly is disclosed. The extendable components of the internal drive assembly are two, or more, telescoping drive shafts each having an alignment structure. The alignment structure ensures that the drive shafts generally maintain their circumferential alignment relative to each other, i.e. the shafts rotate together and maintain their orientation, while allowing the drive shafts to slide axially relative to each other. In one embodiment the drive shafts have a non-circular cross-section, and more preferably, a square cross-section. Each inner drive shaft has a cross-sectional area that is slightly smaller than the next larger outer drive shaft. Thus, the drive shafts may slide axially relative to each other. However, when the drive shafts are rotated, the non-circular shape causes the inner drive shaft and the larger outer drive shaft to engage each other and rotate together.

1. Field of the Invention
This invention relates to extendable tools and, more specifically, to an extendable reaching tool.
2. Background Information
Extendable tools are typically used to interact with overhead objects that may be close or remote. For example, a fruit picker may be able to reach fruit on the bottom of a tree by hand, need a short tool for slightly higher fruit, and a longer tool for fruit near the top of the tree. An extendable tool typically includes an extendable shaft having one or more hollow members disposed in a telescoping relationship. Thus, a user may collapse the shaft when working on/with a close object, or, extend the shaft members when working on a remote object. The shaft members are typically maintained in place by a pin passing through at least two shaft members or a compressive collar.
Some extendable tools have fixed tool heads, e.g. a dust mop, or a flexible tool head, e.g. a device for swapping out light bulbs that has spring-like fingers. As used herein, such devices are not actuatable tool head assemblies as used herein. Other extendable tools include a hand powered actuatable tool head assembly having movable elements, such as, but not limited to, a tree pruner. Such devices typically have a movable blade and a stationary blade/anvil, or, two moving blades. Such extendable tools with an actuatable tool head assembly require a drive assembly in order to allow the user at the bottom end of the extendable tool to actuate the tool head at the upper end of the extendable tool. Devices such as a traditional tree pruner have an external drive assembly, typically including a rope and at least one pulley. Such external drive assemblies are prone to damage, entanglement and other problems.
Internal drive assemblies for extendable tools are typically complex assemblies that are difficult and/or time consuming to assemble. Such internal drive assemblies are complex because the elements must be operable in both the retracted and extended configurations of the handle shaft, but remain enclosed within the shaft where the user cannot, typically, reach the drive assembly elements. That is, for example, the user is not able to access and actuate a locking assembly structured to lock the internal drive assembly components in either the extended or retracted configurations.
One solution is to provide a handle shaft with an access opening to the "internal drive assembly components." Of course, this is not a true internal drive assembly, but rather a partially enclosed external drive assembly. Such assemblies are also prone to clogging with debris, damage, entanglement and other problems. Another solution is to provide a tension member, typically a rope, that is looped about pulleys structured to move together as the shafts move apart. Other internal drive assemblies rely upon rigid drive rods having linking assemblies with ratchet-and-pawl type connectors, see U.S. Pat. No. 6,513,844 (FIG. 6), or connector pins that pass through both drive rods, see U.S. Pat. No. 6,571,479 (FIG. 2-B). Such devices require the internal components to align properly as the user extends/collapses the shaft. Unfortunately, such devices do not always operate as intended and alignment is adversely affected over time as the internal components degrade and/or rust.


Fair usage of working channels in a wireless network is disclosed. A base station associated with a cell within a wireless community monitors the congestion of the working channel of neighboring communities. Upon determining that the congestion of the working channel of a neighboring community is less than that of its existing working channel, the base station initiates a switch to the neighboring community's working channel. Upon joining the new community, the frame structure and other networking parameters and attributes are adjusted.

1. Field of the Invention
Embodiments of the present invention relate, in general, to systems and method for wireless channel management and particularly to the fair usage of channels associated with a wireless network.
2. Relevant Background
Although broadband service has been available for some time, widespread access is still limited. In 2007 there were only 19.6 broadband subscribers per 100 inhabitants in the United States. While the United States ranked 15th in broadband access with respect to the number of inhabitants, the number of broadband subscribers is universally low when compared to the demand for broadband access.
The principle means by which broadband access is currently provided is either via cable or a Digital Subscriber Line ("DSL"). Both cable and DSL present significant barriers to the expansion of broadband access. For example, many are outside of the reach of DSL services. Cable service requires an extensive residential cable infrastructure and is not available to many residences. Lastly, a significant portion of those demanding broadband access feel that the cost of such access is prohibitive.
As an alternative to DSL or cable, the Institute of Electric and Electronics Engineers ("IEEE") developed and promoted a wireless broadband standard. IEEE standard 802.16 defines the Wireless Metropolitan Area Network ("WirelessMAN") air interface specification (also known as the IEEE WirelessMAN standard). This wireless broadband standard is new in comparison to the more mature standards such as 802.11 used for Wi-Fi networks commonly seen in homes and businesses. However, the 802.11 standard is primarily used for small local area networks while the 802.16 standard is designed to be used as a means of allowing wireless broadband access to a larger area as an alternative to cable and DSL connections.
The initial goal of 802.16 is to implement a set of broadband wireless access standards for WirelessMANs. To this end, much of the focus of 802.16 is on the "last mile" that would allow fixed and mobile wireless substations to connect to the fixed wireless base stations ("BSs"), thus allowing the delivery of high-speed Internet connections to the customer.
Because of its wireless nature, WirelessMAN can be faster to deploy, easier to scale, and more flexible, thereby giving it the potential to serve customers not served or satisfied by existing broadband services. WirelessMAN is similar to cellular systems in that it uses BSs that service a radius of several miles. The BS may be on a tower or reside on a tall building or elevated structure. The signal generated from these BSs is routed via standard Ethernet cable directly to a single computer, a hot spot or a wired Ethernet LAN. As will be recognized by one skilled in the relevant art, each BS can possess a transmitter and receiver of some form as well as a machine capable of executing instructions embodied as software. These software instructions can be stored on the BS in memory or conveyed to the BS via a wired link.
For the purposes of the present invention, consider the following definitions.
WirelessMAN-CX is the designation used to describe the realization that adds coordinated coexistence mechanisms to systems operating below 11 GHz in non-exclusively assigned or non-exclusively licensed bands.
WirelessHUMAN is the designation used to describe the realization that adds uncoordinated coexistence mechanisms to systems operating below 11 GHz in non-exclusively assigned or non-exclusively licensed bands.
Coexistence Signaling Interval ("CSI") is a predefined time slot not associated with the CXCC (coexistence control channel), used for coexistence signaling purposes between systems which may have different physical layers ("PHYs"). This technique uses power keyed energy symbols and RSSI (receive signal strength indicator) detection, by a BS to contact its coexistence neighbor BS through one or more coexistence neighbor sub stations ("SSs") in the common coverage area.
Operation Coexistence Signaling Interval ("OCSI") includes all the CSIs other than signal intervals periodically reallocated to OBSs (operating base stations).
Initialization Coexistence Signaling Interval ("ICSI") is the periodically appointed CSI specially used by an Initializing Base Station ("IBS") to contact its neighbor OBS. When the IBS gets the OCSI allocation and starts the operating stage, it will cease from using the ICSI.
By positioning several BSs within a metropolitan area, users can move throughout the area without loss of signal. For example, a user may be connected to the Internet via an 802.11 hot spot at work and then, when undocked, use 802.16 while roaming the city or traveling to the suburbs. One portion of the 802.16 standard (802.16h) provides procedures and improved coexistence mechanisms for license-exempt operation.
These standards, however, fail to address what systems (also referred to herein as BSs and cells) working in a congested channel environment should do when channels are identified with fewer working systems than anticipated. Furthermore, 802.16h does not provide methods to avoid channel switching collisions nor can it guarantee fair channel usage when a system switches to a new working channel.
Consider the example shown in FIG. 1. FIG. 1 shows a configuration of 802.16h BSs with overlapping coverage, as would be known in the prior art. In this example, system 1 110, system 2 115, and system 3 120 operate on channel 1. System 4 125, system 5 130, system 6 135, and system 7 140 operate on channel two. Thus channel 1 is associated with three systems and channel 2 is associated with two instances of 2 systems. In this example three separate communities initially exist, community 1 150 comprising systems 6 and 7, community 2 160 comprising systems 1, 2 and 3, and community 3 170 comprising systems 4 and 5. Assume that system 5 130 ceases to operate or ceases to interfere with system 4 125. In that scenario channel 2 is, in the instance of community 3 170, associated with a single system, system 4 125 while neighboring system 3 120 in community 2 160 is using channel 1 and is associated with two other systems. The prior art fails to address this disparity in congestion within a working channel of neighboring systems and neighboring communities.

Fair channel use in a wireless area network


An apparatus for detecting a potentially dangerous ferromagnetic object carried inadvertently by a person approaching the magnet of a magnetic resonance imaging system (14) uses the fringe field (16) of the magnet and provides guide members (11) defining a path along which the person is prescribed to pass. The path (11) is generally or approximately parallel to the field the path. At least one sense coil and generally two sets of sense coils (12, 13) are located on respective sides of the path (11) s the movement of the ferromagnetic object in the field of the magnet causes a voltage to be generated in the sense coil.

The inadvertent introduction of ferromagnetic objects into the space surrounding high strength magnets such as magnetic resonance imaging magnets and magnets used in magnet guided catheterisation presents an ongoing hazard to both patients and staff in clinical imaging facilities. Such objects, if brought too close to the large magnet that encompasses a patient during scanning, can effectively become missiles that can seriously injure or even kill patient and staff alike, and tragically, more than one fatality has occurred. It is believed that no device exists to protect against the danger. The term "high strength" used herein is intended to include any magnet which has a field strength sufficient that ferromagnetic objects brought into the field can become dangerous.
While normal metal detectors can detect ferromagnetic objects, they also detect non-magnetic metal that can, and routinely is, safely brought up to the magnet. Such detectors therefore give a large number of false alarms and thereby lose any semblance of protective effectiveness.
Current detectors of only ferromagnetic objects assume free-standing use in a non-magnetic environment. Generalising, a first design genre aims to generate a time-varying, low audio-frequency, magnetic field and to observe the changes in that field (via the changes in the inductance of the generating system) caused by the introduction of a ferromagnetic object. However, the creation of such magnetic fields close to an imaging system is proscribed as it interferes with the imaging procedure. A second genre aims to detect changes in the earth's field when a ferromagnetic object moves close by. For such a detection method to have sufficient sensitivity, ferrites are used to enhance the voltages induced in detection coils. However, unless such a detector is to be situated an inconvenient distance from the magnetic resonance imaging suite, the fringe field of the imaging magnet will tend to saturate the ferrites, resulting in greatly impaired efficiency. Further, the presence of a large ferromagnetic object in the magnet suite, that is the detector itself, is potentially dangerous and therefore also proscribed.

Detection of ferromagnetic objects approaching a magnet


An elliptical exercise device has guide links pivotally attached to a frame and foot support links pivotally attached to the guide links. Horizontal control links couple the guide links to a crank system and vertical control links couple the foot support links to the crank system such that rotation of the crank system moves foot receiving areas in a generally elliptical path.

There are a number of exercise devices that operate to allow a user to implement a foot action following a generally closed, curved path of travel, simulating running and/or walking. These devices are generally referred to as "elliptical" exercise devices. Many such elliptical exercise devices are large, complicated, costly, and/or have undesirable characteristics related to the motion of the user's feet.


An endodontal procedure wherein an absorbent dental point is having a scale of graduated depth indicators, arranged in a manner such that during the insertion of the dental point into the root canal the depth to which the tip of the dental point has been inserted into a root canal may be quickly and reliably measured each and every time a subsequent dental point is inserted in the root canal in the course of a root canal procedure.

This invention relates to endodontal surgery and particularly to procedures and instruments employed therein including absorbent pointed probes utilized as swabs in such as root canal surgery.
While becoming less common in the developed countries through better education of the public in the care of the mouth, the inclusion of antidecay additives to such as the water supply and improvements in dental cleaners and washes, decay of the teeth still remains a common problem. When decay of a tooth is quickly noted and has penetrated the enamel (the outer hard surface of the tooth) and only nominally into the dentin (the calcareous portion as opposed to the pulp and nerve structure) repair is readily made by the treatment of cleaning out the affected tissue of the tooth, replacing it with a synthetic material (such as a dental amalgam). Thus, the tooth is said to have been filled, as by the cavity (formed by the removal of the decayed, diseased dentine) being replaced by the filling material.
If the progress of the decay of the tooth (caries) is allowed to progress into the next inner layer, i.e., the pulp containing the nerve and blood vessels, the required treatment to arrest the continuing decay is likely a "root canal", known from its inclusion in the procedure. When the decay of the tooth reaches the pulp, it likely becomes inflamed and may die. Involvement of the pulp usually results in root-end abscess and the associated infection may be passed by the blood stream to other parts of the body, producing inflammation, secondary abscess or other disease. Endodontic treatment, if initiated immediately after injury or involvement of the pulp, can prevent formation of dental abscess, or if the abscess has developed, can usually eliminate the infection without extraction of the tooth. Removal of the pulp includes removal of the live tissue including the nerves and capillary vessels of the tooth. This procedure includes the cleaning of the hollow, canal-like portions of the tooth extending into the tooth's root, by which it is anchored into the jaw bone. Once the tooth, including the root canal, is completely cleaned, the hollow is filled with an air-tight sealer (commonly including medicaments to destroy microorganisms and promote healing) and the remaining cavity filled with the amalgam, or similar material.
The process of adequately cleaning the root canal is a demanding one, requiring the absolute cleaning and sterilization of the canal, otherwise, a "dead cavity" may result. The "dead cavity" is one in which there is remaining tissue to decompose and cause further disease or abscess and may allow further decay within and adjacent the affected tooth including the surrounding periodontal tissue and occasioning the loss of supporting bone and, ultimately, the tooth. The meticulous process of the "root canal" begins with the removal of the diseased, decayed dentine by drilling and aspiration of that tissue and the underlying pulp. Firstly, the tooth is accessed through the crown of the tooth, being opened by drilling through the enamel to locate the pulp chamber. Once the pulp chamber is accessed the particular diseased canal is measured to determine the length of the canal(s) being treated. It is imperative that in the course of the endodontic procedure that the apical foramen, or opening in the canal to the periodontium, not be pierced such that the periodontium be traumatized at and during the cleaning procedure.
There are two conventional methods for determining the length of the canals. The first involves randomly placing a file in the canal and taking an x-ray to determine if the file is near the apex of the canal (beginning of the apical foramen) and repeating this procedure until the successive x-ray reveals that the file is at the apex of the canal. A rubber stopper is then placed on the "handle end" of the file, snugly against the crown of the tooth. By so noting the extent of the depth of the canal, subsequent scraping and cleaning of the canal may be carried out with assurance that the apical foramen will not be invaded in the successive scraping and cleaning. The second method for locating the depth of the canal is to use an electronic apex locator. This is an instrument which attaches to the file and electronically indicates when the apex of the canal is being approached. It is usual to additionally take an x-ray to verify the reading of the electronic measurement. As previously, a rubber stopper is placed on the file at the working distance to ensure that this extent is not exceeded potentially injuring or traumatizing the periodontium.
Several files are then prepared to the proper working depth. The capillaries and nerves contained in the interstices of the canals within the root are first loosened and scraped with narrow files. Progressively larger files are then used to enlarge the canal to completely clean out the canal and ensure that there is a good stopping point at the end of the canal for the later placement of the packing material. Once the canal is completely opened and cleaned of the with this variety of small files, the canals are then cleaned and dried with absorbent dental points, the subject of the present invention.
As explained above, the adequate cleaning of the root canal requires the dentist to probe, scrape, clean and dry the full extent of the interstices of the canal. Subsequent to the cleaning, a medicament is then applied, irrigating the canal to ensure that all debris is removed and to further sterilize the inside of the canal. Sodium hypochlorite is the solution frequently used for this purpose, taking care that it too, reaches the full extent of the canal.
Disease of the tooth, once penetrating the dentine into the pulp, allows one or more of a variety of microorganisms and bacteria to quickly infiltrate the far reaches of the canal. The same type of absorbent dental point may be utilized to deliver the medicament to the extent of the canal as was used to dry it, being typically dipped into the medicament and then routed down into the canal.
The canal is dried with absorbent "paper points". These are tightly rolled papers in the shape of an endodontic file. These paper points are sequentially placed into the canal to dry the canal of the irrigating solution. As with the files used for scraping, it is necessary to prevent the paper points from violating the apex of the canal. Accordingly, it is necessary to fashion some sort of working depth measure, as with the files. A rubber stopper may not readily or routinely be placed on the paper points for setting the working depth. It has become custom to methodically grasp the paper point with cotton pliers, carefully setting the location of each sequential grasp to the previously identified working depth to ensure paper point penetration into the canal to only the desired depth. As can be appreciated, since a dozen or more paper points are customarily cued in an endodontic procedure, the placement of the pliers and subsequent cumberson manipulation of the pliers in using the point are time consuming and restrictive. Further, the requirement for placement of the pliers accurately and ensuring that there is no slippage creates significant opportunity for error.

Endodontal procedure with graduated swab


A brush driving mechanism, which drives a cleaning brush from a retracted position to an operation position opposed to a magnetic head, has a main arm having a tip coupled to the cleaning brush through a shaft. A chassis has a chassis slit, in which the shaft is inserted, for allowing to move the cleaning brush from the retracted position to the operation position by operating the main arm. The chassis slit has a tip portion stops the shaft when the cleaning brush is put into the operation position to position the cleaning brush with respect to the magnetic head.

This invention relates to a recording and/or reproducing device represented by DLT (digital linear tape) or LTO (linear tape open) and, in particular, to a head cleaner mechanism for carrying out cleaning of a magnetic head.
Recording and/or reproducing devices of the type described are developed for use in back-up ones of computer systems and various types of the recording and/or reproducing devices have been proposed in prior art. Such a recording and/or reproducing device serving as the LTO is disclosed, for example, in the patent document WO 00/30096 A1.
The recording and/or reproducing device may be also a tape drive in which a cartridge having a single reel (a supply reel) can be installed. The cartridge may be also called a cassette. The recording and/or reproducing device contains a take-up reel therein. When the cartridge is installed in the recording and/or reproducing device, a magnetic tape is pulled out of the cartridge and then is wound by the take-up reel through a tape-transport path. The tape-transport path is for guiding the magnetic tape pulled out of the cartridge in a magnetic head. The magnetic head exchanges information between the tape and the magnetic head. In addition, the take-up reel is rotationally drivable by means of a real motor.
In the manner which is disclosed in the above-mentioned patent document WO 00/30096 A1, the cartridge comprises a housing, a rotationally drivable supply reel accommodated in the housing, the magnetic tape wound onto the reel hub of the supply reel, and a coupling element which is connected to the magnetic tape in the area of the free end of the magnetic tape and which is held in a coupling position. The coupling element is also called a leader pin.
In order to enable the magnetic tape contained in the cartridge to be wound onto the take-up reel, the magnetic tape should first be brought to the take-up reel with the aid of the leader pin. For this purpose, the recording and/or reproducing device has a pull-out element. The pull-out element is adopted to be coupled to the leader pin. The pull-out element is also called a grabber.
In order to enable the grabber to be coupled to the leader pin, the recording and/or reproducing device includes retaining means adapted to detachably retain the grabber. The retaining means are movably between a standby position and an operating position. A movement of the retaining means into their operating position causes a movement of the grabber in a coupling direction and the grabber and the leader pin to be coupled. On the other hand, a movement of the retaining means out of their operating position causes a movement of the grabber in a direction opposite to the coupling direction and the grabber and the leader pin to be disengaged.
In order to enable the grabber and the leader pin, after they have been coupled, i.e. a pull-out assembly thus formed, to be moved away from the retaining means an to be moved up to the reel hub of the take-up real, the recording and/or reproducing device includes actuating means. The actuating means are simply formed by a pull-out tape. The pull-out tape is guided along the above-mentioned tape-transport path. The pull-out tape is also called a leader tape.
The leader tape has one end connected to the grabber and has its other end connected to the reel hub of the take-up reel. Thus, by driving the take-up reel in a taking-up direction by a reel motor, the pull-out assembly can be moved away from the retaining means and up to the reel hub of the take-up reel with the aid of the leader tape which is simple in structure. At the reel hub, the pull-out assembly are brought to each other.
In the manner which is described above, the above-mentioned patent document WO 00/30096 A1 discloses the recording and/or reproducing device (the tape drive) employing the leader tape.
On the other hand, another recording and/or reproducing device employing a pantocam arm in lieu of the leader tape is disclosed, for example, in U.S. Pat. No. 6,067,211 to Chliwnyj et al., entitled: "Oscillating Magnetic Head and Stationary Brush Cleaning Apparatus."According to U.S. Pat. No. 6,067,211, the recording and/or reproducing device employs a pantocam arm which carries a leader pin for capturing a leader block, which is attached to the magnetic tape to be processed. After capturing the leader block, the pantocam arm swings the leader block around an arcuate tape guide and then lodges the leader block in a reel. When the reel is rotated, the magnetic tape moves adjacent to the magnetic head, which is located intermediate the tape guide. After the magnetic tape is processed, a supply reel in the cartridge returns the magnetic tape to the cartridge and the pantocam arm delivers the leader block to the cartridge, where it is released.
In such a recording and/or reproducing device, it is important to periodically clean out dirt on a surface of the magnetic head to obtain stable outputs of recording/reproducing. Therefore, the recording and/or reproducing device comprises a head cleaning mechanism. Inasmuch as the head cleaning mechanism removes the dirt on the surface of the magnetic head, a position relationship between both is important.
Chliwnyj et al. discloses a "magnetic tape drive" comprising a cleaning apparatus for cleaning the air bearing surface of a magnetic head of the magnetic tape drive by employing components of an actuator for oscillating the magnetic head against bristles of brush assembly. In the magnetic tape drive according to Chliwnyj at al., circuitry is provided which senses the appropriate time to commence the cleaning action and continues the cleaning action for an appropriate duration when the magnetic tape is off the magnetic head. The circuitry causes the actuator to move the magnetic head in oscillatory motion against stationary bristles of a brush assembly which are selectively brought into engagement with the magnetic head. The engagement and disengagement of the bristles with respect to the magnetic head are implemented by a lever arm which has camming surface which are engageable with a leader pin which moves a leader block and magnetic tape about a guide and across the magnetic head.
A further recording and/or reproducing device employing a threader arm in lieu of the leader tape is disclosed in Japanese Unexamined Patent Application Publication No. Hei 11-328635 (JP-A 11-3286351). JP-A 11-328635 discloses a "magnetic tape apparatus" which intends to be simple in structure and to enhance the reliability to the cleaning operation. The magnetic tape apparatus disclosed in JP-A 11-328635 includes a magnetic head having a read track position adjustment means and a brush which comes in touch with the magnetic head when the magnetic tape is not loaded and which opens a travel path for the magnetic tape when the magnetic tape is loaded. When the magnetic tape is not loaded, the magnetic head is driven by the read track position adjustment means, so that the magnetic head is cleaned.
In the recording and/or reproducing devices without employing the leader tape as disclosed in the above-mentioned U.S. Pat. No. 6,067,211 or the above-mentioned JP-A 11-328635, it is possible to arrange a cleaning brush so as to face the cleaning brush to the magnetic head with a running path of the magnetic tape put therebetween because there is no leader tape. Therefore, it is possible to easily carry out positioning of the cleaning brush with respect to the magnetic head.
However, in the recording and/or reproducing device employing the leader tape as disclosed in the above-mentioned patent document WO 00/30096 A1, it is impossible to arrange the cleaning brush so as to face the cleaning brush to the magnetic head. This is because the leader tape is between the takeup reel and the retaining means. Therefore, in order to drive the cleaning brush, a brush driving mechanism requires a lot of parts which operate when interlocked with a driving source. As a result, in order to accurately position the cleaning brush with respect to the magnetic head, it is necessary to improve accuracy in each part and to make a width of the cleaning brush larger. Accordingly, the conventional brush driving mechanism is disadvantageous in that it drives up costs and it takes up space for the placement of the parts.
In addition, it is necessary to hold and fix the cleaning brush to be stable during cleaning of the magnetic head after positioning the cleaning brush with respect to the magnetic head.

Recording and/or reproducing device having a positioning arrangement for positioning a cleaning brush