The invention relates to a clock synchronous type semiconductor device that accepts an input signal inputted from the exterior in synchronization with a clock signal. The semiconductor device according to the invention includes an input signal receiving unit that receives an input signal inputted from the exterior, where the receiving is done in synchronization with a clock signal; a clock timing selecting unit for outputting a clock selecting signal; and a clock generating unit that, in response to receiving a clock selecting signal and an external clock signal, generates a clock signal at a predetermined timing which corresponds to a signal level of the clock selecting signal, and outputs the clock signal to the input signal receiving unit, wherein it is possible to securely accept an input signal regardless of the frequency of the external clock signal.

1. Field of the Invention
The present invention relates to a clock synchronous type semiconductor device that accepts input signals inputted from the exterior in synchronization with a clock signal.
2. Description of the Related Art
Generally, a semiconductor device such as an integrated circuit, etc., is roughly divided into a logic LSI such as a microcomputer, etc., and a memory LSI such as a DRAM (Dynamic Random Access Memory), etc. The microcomputer has been publicly known as a clock synchronous type semiconductor device. On the other hand, recently, a clock synchronous type has been developed as a synchronous DRAM in the memory LSI.
The synchronous DRAM operates an interface circuit at a high rate in synchronization with an external clock signal inputted from the exterior, and enables writing and reading of data at a high rate. For example, a synchronous DRAM, the maximum operating frequency of which is 100 MHz or more, has been developed.
FIG. 1 shows an example of configuration of an input interface unit in this type of semiconductor device. The input interface unit 1 is provided with a plurality of input signal accepting circuits 3.
The respective input signal accepting circuits 3 accept an external clock signal CLK and an input signal Din (a) (or Din (b)). The input signal accepting units 3 output internal signals Doutz (a), Doutx (a) (or Doutz (b), Doutx (b)) to an internal circuit 5. Also, the internal signal Doutz is an in-phase signal of the input signal Din, and the internal signal Doutx is an antiphase signal of the input signal Din.
The above-described input signal accepting circuits 3 accepts an input signal Din in synchronization with the external clock signal CLK and output the accepted signal into the internal circuit 5 as internal signals Doutz and Doutx.
FIG. 2 shows an example of acceptance timing of an input signal Din in the input interface unit 1 shown in FIG. 1. In this example, the inputting period of the input signal Din is defined in terms of setup time and hold time with respect to rise of the external clock signal CLK.
The setup time tDS is a specification of the minimum time necessary to confirm the input signal Din prior to a rise of the external clock signal CLK, and the hold time tDH is a specification of the minimum time necessary to hold the input signal Din after a rise of the external clock signal CLK.
By inputting an input signal Din in compliance with the above-described timing specification, the input signal Din is accepted by the rise of the clock signal CLK to generate internal signals Doutz and Doutx.
The setup time tDS and hold time tDH are determined so that the input signal Din can be accepted without fail under the worst conditions, taking into consideration the characteristic fluctuations among semiconductor devices, which are produced in a semiconductor fabrication process, and temperature and/or supply voltage to operate the semiconductor devices.
However, it is necessary that users who have this type of a semiconductor device mounted in a system equipment establish an input signal Din, which is inputted into the semiconductor device, prior to the setup time tDS, and designs the timing in the system equipment to hold it longer than the hold time tDH, as described above.
The system equipment needs a circuit to satisfy the setup time tDS and a circuit to satisfy the hold time tDH, respectively, in order to generate input signals Din, so the circuit configuration of the system equipment has been increasing in scale and has been becoming more and more complicated.
In the case of a semiconductor device whose operating frequency exceeds 100 MHz, generally, the cycle of the external clock signal CLK becomes 10 ns or less. Resultantly, the allowance in the timing design at the system equipment is reduced, and it was difficult to generate input signals Din on the basis of the above-described timing specification.
In particular, in order to secure the setup time tDS of an input signal Din, a rise or a fall of an eternal clock signal CLK one clock cycle beforehand needs to be used, wherein the timing design was very difficult where the cycle of the external clock signal CLK is short.
Therefore, the inventors considered outputting an input signal Din from the system equipment as soon as the external clock signal has done transition, generating a clock signal delayed by a predetermined time with the external clock signal CLK in the above-described input interface unit 1, and accepting an input signal Din in synchronization with the clock signal.
FIG. 3 shows a configuration of an input interface unit 1 that has been considered by the inventors. The input interface unit 1 has the above-described input signal accepting circuits 3 and an inverter 7.
The inverter 7 inputs the external clock signal CLK, and outputs an inverted clock signal /CLK of the external clock signal CLK. The input signal accepting circuits 3 inputs the inverted clock signal /CLK. The other configuration is identical to that shown in FIG. 1.
FIG. 4 shows timing for accepting input signals Din in the input interface unit 1 shown in FIG. 3.
The input signal Din is accepted at a rise (=a fall of the external clock signal CLK) of the inverted clock signal /CLK. In this case, the inputting period of the input signal Din is a specification of the setup time tDS1 and hold time tDH1 with respect to the rise of the inverted clock signal /CLK.
Therefore, when the inputting period of the input signal Din can make the time tDS from the rise of the external clock signal CLK to the establishment of data smaller than a xc2xd cycle of the external clock signal CLK, only the hold time tDH with respect to the rise of the external clock signal CLK need be satisfied.
Resultantly, in the system equipment, users only has to design the timing so that an input signal Din simultaneously generates with the rise of an external clock signal CLK or after the rise thereof, and so that the rise it is held for only the hold time tDH. That is, designing of timings can be facilitated.
FIG. 5 shows the configuration of another input interface unit 1 considered by the inventors. The input interface unit 1 has the above-described input signal accepting circuits 3 and a delay circuit 9.
The delay circuit 9 receives the external clock signal CLK, and outputs a delay clock signal DCLK delayed by a predetermined time to the external clock signal CLK. The respective input signal accepting circuits 3 receives the delay clock signal DCLK. The other configuration thereof is identical to that shown in FIG. 1.
The delay circuit 9 is composed of, for example, a capacitor and a resistor and has a predetermined time constant.
FIG. 6 shows the accepting timing of an input signal Din in the input interface unit 1 shown in FIG. 5.
The input signal Din is accepted at the rise of the delay clock signal DCLK delayed by delay time xe2x80x9cDelayxe2x80x9d from the rise of the external clock signal CLK. In this, the inputting period of the input signal Din is a specification of the setup time tDS2 and hold time tDH2 with respect to the rise of the delay clock signal DCLK.
Accordingly, when the time tDS from the rise of an external clock signal CLK to the decision of data can be made shorter than the delay time xe2x80x9cDelayxe2x80x9d, the inputting period of an input signal Din only needs to satisfy the hold time tDH of the rise of the external clock signal CLK.
Therefore, in the system equipment, users only need to design the timing so that generating input signal Din simultaneously with the rise of an external clock signal CLK or after the rise thereof as in the input interface unit 1 shown in FIG. 3, and hold the rise of the input signal Din for only the hold time tDH. That is, designing timings can be facilitated.
The considerations made by the inventors are not publicly known so far.
However, in the input interface unit 1 having an inverter 7 shown in FIG. 3, an input signal Din is accepted by using an inverted clock signal /CLK obtained by inverting the external clock signal CLK. Therefore, the timing at which internal signals Doutz and Doutx outputted to the internal circuit 5 delays by almost the half of a clock from the timing of the rise of the external clock signal CLK.
For example, in the case where the input interface unit 1 is applied to an accepting part of address signals and data signals in a clock synchronous type memory LSI such as a synchronous DRAM, etc., the access time such as writing time and reading time delays by one half of a clock.
There is a problem in that, although the delay scarcely influences the access time when the frequency of an external clock signal CLK is high, the influence upon the access time is made large as the frequency of the external clock signal CLK, is lowered.
That is, the access time of a memory LSI to which the input interface unit 1 is applied becomes roughly equivalent to the sum of the time required from the selection of a memory cell of a designated address to the output of the selected memory cell to the exterior and the time of one half of a clock of the external clock signal CLK. Although the former time is almost constant without depending upon the frequency of the external clock signal CLK, the latter time may be lengthened as the frequency of the external clock signal CLK is lowered. Therefore, the longer the cycle of the external clock signal CLK becomes (the lower the frequency becomes), the ratio of one half of a clock of the external clock signal CLK to the access time increases, and the influence thereof upon the access time may be increased.
On the other hand, the input interface unit having a delay circuit 9 shown in FIG. 5 accepts an input signal Din, using a delay clock signal DCLK in which the external clock signal CLK is delayed.
The delay time xe2x80x9cDelayxe2x80x9d of the delay circuit 9 may fluctuate, due to the characteristic fluctuations among semiconductor devices which are produced in a semiconductor fabrication process, temperature and/or supply voltage when operating the semiconductor device. The fluctuation does not depend on the frequency of the external clock signal CLK.
The higher the frequency of the external clock signal CLK, the larger the influence due to fluctuations of the delay time xe2x80x9cDelayxe2x80x9d. In detail, for example, in the case where the frequency of the external clock signal CLK is 125 MHz (clock cycle is 8 ns) where the delay time xe2x80x9cDelayxe2x80x9d of the delay circuit 9 fluctuates in a range of 2 ns through 7 ns, the allowance between the maximum value of the delay time xe2x80x9cDelayxe2x80x9d and the clock cycle is only 1 ns, wherein it becomes difficult to design the internal timing of a semiconductor device.
The above-described malfunction occurs when producing a semiconductor device.
There are two kinds of production processes in the semiconductor devices, one of which is a single wafer process in which a wafer in which a plurality of semiconductor devices are formed by being processed one by one, and the other of which is a batch process in which a plurality of wafers are simultaneously processed. The single wafer process is, for example, a photolithography process, and the batch process is, for example, a heat treatment process.
Generally, in the single wafer process, characteristic fluctuation is liable to occur among semiconductor devices in the same wafer, and in the batch process, characteristic fluctuation is liable to occur in different wafers.
As such fluctuations overlap through a plurality of production processes, the fluctuation of the maximum operating frequency of produced semiconductor devices is subjected to a mountain-like distribution having a peak at the middle, as shown in FIG. 7.
The semiconductor devices are classified into three types, the fastest type, highspeed type and standard type, for example, depending on the maximum operating frequency, through a probe test in the wafer state and a selection test after assembly is completed.
At this time, in the case where the input interface unit 1 having an inverter 7 shown in FIG. 3 is applied to a semiconductor device, influence on the access time is increased in the standard type. The semiconductor devices are handled as defective units where the access time thereof exceeds a predetermined time.
In the case where the input interface unit 1 having a delay circuit 9 shown in FIG. 5 is applied to a semiconductor device, influence due to fluctuations of the delay time xe2x80x9cDelayxe2x80x9d is increased in the fastest type. Semiconductor devices are handled as defective units where internal signals Doutz and Doutx cannot be accepted by the internal circuit 5.
As a result, an expected yield cannot be obtained, and the production cost of semiconductor devices is remarkably increased.
It is therefore an object of the invention to provide a semiconductor device that is capable of receiving input signals without fail regardless of the frequency of an external clock signal.
It is another object of the invention to provide a semiconductor device in which the timing of an internal clock signal, which accepts an input signal, is set when the semiconductor device under operation.
It is still another object of the invention to provide a semiconductor device in which the timing of an internal clock signal, which accepts an input signal, is set in a semiconductor fabrication process.
It is yet another object of the invention to provide a semiconductor device in which the timing of an internal clock signal, which accepts an input signal, is automatically set according to the frequency of the external clock signal.
According to one of the aspects of the semiconductor device of the invention, a clock timing selecting unit outputs a predetermined clock selecting signal. A clock generating unit receives a clock selecting signal and an external clock signal and generates a clock signal at a predetermined timing which corresponds to a signal level of the clock selecting signal. The input signal receiving unit receives an input signal in synchronization with the clock signal outputted from the clock generating unit. Therefore, the input signal receiving unit is capable of receiving an input signal (address signal, data signal, etc.,) by means of a clock signal having the optimum timing in response to the frequency, etc., of the external clock signal used. That is, it is possible to accept the input signal without fail regardless of the frequency of the external clock signal.
According to another aspect of the semiconductor device of the invention, a clock generating unit is provided with a plurality of internal clock generators, and the respective internal clock generators generate internal clock signals whose phases are inverted compared to that of the external clock signal, or which are delayed from the external clock signal by a predetermined time. The input signal receiving unit receives an input signal using the selected internal clock signal. Therefore, the input signal receiving unit is capable of receiving an input signal even in the case where the input signal is inputted simultaneously with the edge timing of an external clock signal. Resultantly, it becomes possible to relieve the specified input timing of input signals, wherein the timing design of a system equipment on which the present semiconductor device is mounted can be facilitated.
According to yet another aspect of the semiconductor device of the invention, the first internal clock generator generates an internal clock signal whose phase is inverted compared to the external clock signal. The second internal clock generator generates, by a delay circuit, a delayed internal clock signal which is delayed compared to the external clock signal. The clock generating unit outputs the inverted internal clock signal to the external clock signal, using the first clock generating unit, where the clock selecting signal is one signal level. The clock generating unit generates and outputs a delayed internal clock signal by the delay circuit of the second clock generating unit where the clock selecting signal is the other value. Therefore, for example, by changing the signal level of the clock selecting signal to the one or the other signal level according to a high or low level of the frequency of the external clock signal by means of, for example, the clock timing selecting unit, the input signal receiving unit receives an input signal by the inverted internal clock signal depending on the cycle of the external clock signal where the frequency of the external clock signal is high, and receives an input signal by a delayed internal clock signal that does not depend on the cycle of the external clock signal where the frequency of the external clock signal is low. That is, the input signal receiving unit is capable of accepting an input signal at the optimal and fastest timing in response to the frequency of the external clock signal.
According to yet another aspect of the semiconductor device of the invention, clock selecting information is provided in the selecting information setting unit. The clock timing selecting unit outputs a clock selecting signal according to the clock selecting information. Accordingly, it is possible to set clock selecting information in advance when operating a semiconductor device.
According to yet another aspect of the semiconductor device of the invention, a selecting information unit comprises a register that is able to be set from the exterior. The clock selecting information is set by accessing the register on a system equipment in which the semiconductor device is mounted, for example. The clock timing selection unit outputs a clock selecting signal having a signal level responsive to a storage value of the register. As the result, it is possible to set selecting information in response, to the frequency of the external clock signal in use when operating the semiconductor device, so that users are provided with a semiconductor device having a wide range of operating frequency.
According to still another aspect of the semiconductor device of the invention, the selecting information setting unit is composed of a fuse. The clock selecting information is set by whether or not the fuse in the test process blows. The clock timing selecting unit outputs a clock selecting signal of a signal level according to whether or not the fuse blows. Therefore, for example, the clock selecting information that is optimal for a produced semiconductor device can be set by blowing and not blowing the fuse in accordance with the maximum operating frequency evaluated in a probe test.
According to yet another aspect of the semiconductor device of the invention, the selecting information setting unit is composed of a bonding pad and bonding wire. The clock selecting information is set by changing the connection port of the bonding wire connected to the bonding pad in the assembly process. The clock timing selecting unit outputs a clock selecting signal of a signal level according to a voltage value given to the bonding wire connected to the bonding pad through the bonding wire.
According to yet another aspect of the semiconductor device of the invention, the selecting information setting unit is composed of a conductive layer formed at a predetermined position on a semiconductor substrate corresponding to the pattern of a photo mask. The clock selecting information is set by changing the photo mask used in a semiconductor fabrication process. The clock timing selecting unit outputs a clock selecting signal of a signal level corresponding to the voltage value at the connection port of the conductive layer. Since the clock selecting information is set in the photolithography process and etching process which are in the normal semiconductor fabrication process, the clock electing information is set without the provision of any special process.
According to yet another aspect of the semiconductor device of the invention, the clock timing selecting unit is provided with a frequency detector that detects the frequency of the external clock signal. The clock timing selecting unit automatically selects the internal clock signal according to the frequency of the detected external clock signal. Resultantly, in the semiconductor fabrication process, it is unnecessary to set the clock selecting information, or, it is unnecessary to set the clock selecting information to a system equipment having a semiconductor device mounted thereon.


A magnet assembly has a number of axially-aligned coils, the radial mid-point of each coil being axially-aligned with a portion of a radial extent of an adjacent coil in the assembly. Compression blocks are provided between adjacent coils at circumferential intervals, to retain the coils in fixed relative positions.

Field of the Invention
The present invention relates to methods for the production of solenoidal magnets composed of several axially aligned coils, and solenoidal magnets so produced.
The present invention particularly relates to such solenoidal magnets for use as a magnetic field generator in a Magnetic Resonance Imaging (MRI) system. In particular, the invention relates to such magnets formed of superconductive wire.
Description of the Prior Art
In known magnet arrangements, a solenoidal magnet typically has end coils of relatively large number of turns, and hence larger cross-section and a number of inner coils of smaller number of turns and hence smaller cross-section. Conventionally, an accurately machined former, such as an aluminium tube, is provided with appropriately shaped slots into which wire is wound to form the coils. The coils may be impregnated with a thermosetting resin, either by wet-winding, in which a wire is passed through a bath of resin before being wound onto the former, or the coils may be wound dry, with the completed coils and former later being impregnated in a bath of resin. Similar impregnation may be performed with a wax, but the present description will refer to "resin" only, for brevity.
Alternatively, arrangements of moulded coils are known. In these arrangements, coils are wound into moulds, and the finished coil impregnated with resin within the mould. The resin is then cured, and a solid coil embedded in resin is produced. These moulded coils are then assembled into a magnet, for example by clamping onto a former or other mechanical support structure.
A known compromise arrangement has the inner coils, those toward the axial centre of the magnet, arranged on a former, with end coils moulded and mechanically attached to the former. The end coils tend to be larger in cross-section, and less critical in their placement. This compromise arrangement enables smaller, less expensive formers to be used, while maintaining accurate relative positioning between the inner coils.
These known arrangements suffer from certain drawbacks.
In use, magnet coils are subject to large forces, due to interaction of the coils with the magnetic fields produced. Some of these forces act axially, and urge the coil towards a wall of the former, while other forces act radially, tending to expand the coil to a larger diameter, or compress it onto the former. These forces may cause the coils to move relative to the former. Such movement may cause heating of the coils, which in superconducting magnets may lead to a quench.
The forces acting on the coils may cause the former to flex. The former needs to be large, heavy and mechanically robust to resist those forces. Due to flexure in the former, the force reaction path resisting the coil forces then acts essentially at the inner edges of the coils, which is misaligned from the line of action of the coil body force, which may be considered to act in an axial direction, through the radial mid-point of the coil cross-section. This contributes to a tendency to flex the former. The forces are also borne by a limited surface area of the coils. This may cause deformation of the coils themselves, which may also lead to quench in a superconducting coil.
The majority of the force acts upon the magnet's end coils, and shield coils if present. Inner coils are relatively lightly loaded, but are required to be the most accurately positioned in space to create a homogeneous field as required for imaging.
An accurately-machined former, as conventionally used, is expensive, and is only available from a limited number of suppliers. Transport costs from the former factory to the magnet winding facility may be significant. Storage of the large former may be difficult and costly.
Conventionally, separate coils wound within a former, or individually moulded coils are connected together by wiring and connections made after winding and impregnation of the coils is complete. Much time, and space, has been dedicated to ensuring that these connections are firmly retained in position, and cannot move when the magnet is in operation. A slight movement of these wires may be enough to cause the magnet to quench.

Solenoidal magnets composed of multiple axially aligned coils


The hydraulic vacuum pump (HVP) uses a centrifugal water pump with unconventional inlet and outlet connections that cause unconventional patterns of fluid flow. Valves are not required for operation. The submerged pump outlet must be kept open and unobstructed to flow, and must also be no smaller in cross-sectional area than the submerged pump-inlets. The pump inlet branches into two openings, each for a distinctly different purpose. A submerged pump-priming inlet branch uses an orifice of predetermined size to assure minimum liquid flow while also controlling both rate and limit of air extraction. The other inlet opening is connected to a fixed priming-siphon from which air is extracted as it is mixed with liquid in the pump in a novel automatic, pressure-activated cyclic action, and freely expelled in the outflow. The crown of the priming-siphon is equipped with an air inlet that may be connected by leakproof channels to the crowns of one or more other siphons that have the same or lesser elevations for priming, or to other enclosed spaces from which air that may be mixed with liquid is to be extracted at subatmospheric pressure.

1. Field of the Invention
The present invention relates generally to vacuum pumps and siphons, and more specifically to a hydraulic vacuum pump that uses a centrifugal pump in a new way to evacuate gases along with liquids, for priming siphons and for other uses where gases must be removed while mixed with liquids at subatmospheric pressure.
2. Description of Related Art
A siphon is a leakproof solid channel, shaped and positioned to carry liquid from a source up and over an elevated point and down to an outlet at a lower level. A siphon must have at least its upper (source) end submerged to allow atmospheric pressure to hold it full of liquid after it has been primed (filled), so that flow is powered by gravity. A siphon's elevation is the vertical rise from the liquid-surface of the source to the crown (highest part) of the siphon. Pressure within the elevated parts (every part between the source-surface and the crown) of a working siphon is always subatmospheric. The maximum elevation of liquid in a siphon depends on the specific gravity (sg) of the liquid and atmospheric pressure. Water at 1.0 sg can be elevated in a siphon to no higher than about 34 feet at sea level.
It should be noted that a fully operating siphon is very energy efficient. It moves liquid at the rate of flow the aforementioned factors permit, using only gravity for motive power and atmospheric pressure to hold liquid. But reliability of siphons needs improvement. Accidental starting or stopping of a siphon is often inconvenient, or costly, or dangerous.
Siphons are used in systems for flood control in rivers and reservoirs, chemical processes, desalination, power generation, motor vehicles, manufacturing, medicine, brewing, farming, livestock care, hatcheries, zoos, aquariums and many other uses.
Siphons can be built from many different man-made materials including reinforced concrete, pipes and fittings of metal or plastic, flexible tubing, and others. Modem materials make far better siphons than were available to ancient builders.
Atmospheric pressure of 14.7 pounds per square inch at sea level, is the weight of air pressing down on the earth's surface, and is the force that holds liquid in a siphon. Subatmospheric pressure, also called a vacuum, is in the elevated parts of working siphons.
Subatmospheric pressure in the elevated parts of a liquid-filled siphon, allows any leak to admit air. The lower pressure also causes gases that are dissolved in the liquid to effervesce. Thus, whenever enough air or other gases gradually enter the highest part or crown of a siphon to drop the liquid level below the crown, flow through the siphon is reduced. When the level drops below the bend or crest of the siphon, the flow stops entirely. And whenever air can enter freely, from an unsubmerged end or an unusually large break or leak in an elevated part, the siphon empties all liquid as fast as it can flow out. Freely admitting air to stop siphon flow can be done by installing a "vacuum breaker" valve at the crown. Blocking the siphon channel with a shutoff valve or end-cap will also stop flow, as will frozen liquid or clogged foreign matter. Most commonly the liquid moved through a siphon is unfrozen water, but many other free-flowing liquids can be siphoned. Most commonly the gas to be removed from a siphon is air, but any other gas that behaves like air could be there.
Before a siphon can efficiently start to carry water or any other liquid, all of the air or any other gas inside the siphon must be replaced by liquid. This process is called priming, filling or starting the siphon.
There are several well-known ways to start a siphon:
Inversion siphon-priming, well known to brewers, aquarium keepers and others, may be the most ancient method of siphon-starting still commonly used. A small siphon is inverted, filled by either immersion or pouring, and outflow is blocked until it is placed into a working siphon position.
The same human lung-power that makes a soda-straw work, is another ancient method often used to start small siphons.
Self-priming siphons have a low elevation so that siphoning begins when a rise in water level causes liquid to enter from the upper end, enough to cause continuous flow. The most common man-made self-priming siphons are rather large, typically made of reinforced concrete, with diameter, elevation and length measured in meters, most often used for controlling water levels in reservoirs. Other examples of self-priming siphons on a comparatively miniature scale, include U.S. Pat. Nos. 5,738,137; 4,846,206; and 4,124,035. The latter one is so small that capillary action affects its performance.
Induced-flow can start siphons that have a size or shape that restricts air-inlet from the lower end. Liquid is caused to flow through from the source end of the siphon, by any one of several different methods, until unassisted gravity-power can sustain continuous flow. The oldest known method of this kind was invented in the first century AD by Hero of Alexandria. The Internet in May, 1998, displayed two similar methods. One, under Siphons, was Starting a Python Siphon (for aquariums) by George Booth; and the other, under Siphons & Tubing, Phil's Psyphon Starter by brewguys.
Pumping or pouring full to the brim of an opened siphon-crown, will effectively prime a siphon in working position, provided that its lower ends are blocked shut. The crown-opening is then closed airtight before unblocking the lower ends; then flow can begin. This method of siphon-filling was introduced for an aquarium fish-bridge in U.S. Pat. No. 5,067,439.
Vacuum siphon-priming can fill any size siphon that is in working condition, either before startup or during operation, without moving the siphon itself. Air is extracted from the crown of the siphon, which allows atmospheric pressure to force liquid up into the evacuated space.
Other siphon-starters can only be used before the siphon begins to operate. Air in a working siphon inevitably rises to the top. If siphon-starting is limited to one of those methods and air in the siphon stops its flow, the startup process must usually be repeated after correcting, if possible, whatever problem allowed the air to get in.
The simplest form of vacuum-pump air-extraction for small siphons is a hand-operated bellows or squeeze-bulb equipped with one-way valves. Examples of this method of siphon-priming can be seen in U.S. Pat. Nos. 5,230,298; 3,670,758; and 192,595.
Many kinds of power-driven vacuum machines are well known. They include household vacuum cleaners, the inlet of an air pump or air compressor, industrial vacuum pumps that rapidly exhaust high volumes of air, sophisticated scientific machines that attain a near-perfect vacuum, and others. All of these are made for handling air or other gases alone, not mixed with liquids. Most air pumps and vacuum pumps would be damaged if liquid entered the pump itself. A method of either separating liquids from gases ahead of the pump inlet, or stopping the pump before liquid can enter, is commonly found where such machines may encounter liquids. With protection from liquid entry, vacuum machines designed to quickly move high volumes of air can be a very efficient way to exhaust air from a siphon, within limits of how much low pressure it can produce.
An example of vacuum-priming in a large-scale siphon, as described in a reference volume, was operated in a desalination plant on the island of Malta in 1975. A siphon 200 meters long, 4 meters in elevation and 0.8 meters diameter carried sea water to the plant. It was primed by a vacuum pump in about two hours. The vacuum pump was then operated continuously to extract entrained air.
Also well-known, but not found applicable to siphon-priming, is the subatmospheric pressure (vacuum) available at the inlet of any liquid-handling pump, whether centrifugal or positive-displacement. Measurement of the low pressure of such pump-inlets is often expressed in terms of "suction lift", which is the vertical distance that atmospheric pressure will force water upward to the pump inlet, minus losses due to flow-friction in the line. A mechanic's reference book typically states a limit of "practical suction lift" on positive-acting pumps as about 22 feet, and on centrifugal pumps about 15 feet. However, in order to obtain even that much "lift", a liquid handling pump must he "pre-primed"; that is, it must already be liquid-filled, or have liquid flowing through.
A dry centrifugal pump has no suction lift at all, and a dry positive-displacement pump would need very unusual seals against air leaks before it could produce enough suction lift to prime a siphon of very low elevation. Furthermore, positive displacement pumps often have difficulties attempting to handle air/water (gas/liquid) mixtures.
The venturi effect, based on Bernoulli's theorem which explains how pressure drops as speed increases in fluid flow, is another prior art way to vacuum-prime a siphon. Typically, the outflow of a liquid pump is passed through a venturi device to produce vacuum. Efficiency is low, but venturi-produced vacuum can prime a low-elevation siphon. Examples of venturi siphon-priming can be found in U.S. Pat. Nos. 4,036,756; 4,579,139; and 4,951,699.
The first fish-bridge siphon that interconnected two aquariums appeared in U.S. Pat. No. 192,595. Subsequently, fish bridge siphon variations are found in U.S. Pat. Nos. 1,576,462; 3,903,844; 5,067,439; and 5,230,298. More fish-display siphons for aquariums with very complex designs can be found in U.S. Pat. Nos. 5,282,438 and 5,605,115.
The inventor's U.S. Pat. No. 3,903,844 included circulation of aerated and filtered water in a double-tank fish-bridge siphon. A smaller siphon was built into the back edge of the fish-bridge. A small opening at the crown of the smaller siphon interconnected the two siphons. Water flowed slowly through the smaller siphon to the inlet of an air-bubble pump in one tank, and returned to the other tank through the larger siphon. The interconnection assured that neither siphon could carry water if the other stopped flowing. This effectively prevented tank overflow.
A large scale siphon design for tidal water power to produce electricity is found in U.S. Pat. No. 4,288,985. A giant siphon would carry the rise and fall of ocean tides through a hydro turbine generator. However, one of its major design shortcomings is the omission of a way to prime the huge siphon or to maintain prime, essential for successful operation.
In all of the prior art methods of siphon-priming there are many needs for improvement:
(a) Priming by inversion is undesirable wherever spills could be damaging or dangerous; PA1 (b) Lungpower siphon-filling, besides other limitations, is often unsanitary and hazardous; PA1 (c) Self-priming siphons work only for low-elevations, with limited control; PA1 (d) Induced-flow siphon-priming works well only in limited applications; PA1 (e) Pumping or pouring to fill a siphon demands extra steps for too-small advantage; PA1 (f) A conventional vacuum-pump is inefficient for siphon-priming. A vacuum pump good for efficient siphon startup-priming is overpowerful for maintaining prime in an operating siphon; and a vacuum pump that can maintain prime efficiently is underpowered for startup. Either way, when the siphon is filled, a need to prevent liquid entry to the pump is an unwelcome complexity; PA1 (g) Siphon-priming by utilizing subatmospheric inlet pressure ("suction-lift") of liquid handling pumps is theoretically possible, but no practical prior examples have been found; PA1 (h) Venturi-effect siphon-priming uses a small fraction of pump-outflow power to produce only enough vacuum to fill low elevation siphons; PA1 (i) High-elevation, high-volume and long-extension siphons have seldom been attempted, largely due to the limitations of available priming methods; PA1 (j) After a siphon is primed by any method that does not continue during operation, gases in the siphon accumulate at the top. When the liquid level drops to a predetermined level the flow stops, re-priming is necessary before flow can resume; and PA1 (k) For lack of reliable and efficient siphon-priming, few if any pipelines use siphons. Most pipeline flow is forced through by pumps consuming energy from non-renewable resources. PA1 (a) To provide a simple and effective hydraulic vacuum pump (HVP) that requires no valves and only one mechanical moving part, the pump impeller; PA1 (b) To provide a new and improved way of starting siphon flow by simply starting the hydraulic vacuum pump (HVP), which causes siphons to prime and remain primed to transport water by the power of gravity continuously with no further operator action; PA1 (c) To provide a HVP that can serve to prime and maintain prime equally well in siphons that transport or recirculate liquid; PA1 (d) To provide a HVP which, when used to maintain prime in elevated-siphon segments of a high-volume, long-distance fluid transport pipeline, would enable pipeline fluid flow by gravity power in place of pumps that consume energy from non-renewable resources. Power consumed for startup vacuum-priming and HVP priming maintenance to enable gravity-powered siphon flow, would be a small fraction of power consumed by pump-powered flow. Also, minor leaks in the miles of elevated-siphon-sections of a pipeline would not lose contents or contaminate environment; but air would leak in and signal the problem, and contents would not leak out; PA1 (e) To provide a HVP that can prime as many kinds of siphons as possible, including single or multiple legs, high or low volume, long or short extension, high or low elevation, and single or multiple elevations of single or multiple interconnected siphons; PA1 (f) To provide a HVP that will work with any kind of pump that has subatmospheric inlet pressure and will not trap gases or be damaged by mixtures of liquids and gases; PA1 (g) To provide a new kind of vacuum pump that will continuously and reliably extract gases mixed with or entrained in liquids, from siphons or other space to be vacuumed; PA1 (h) To provide a HVP that is adaptable to work with many different combinations of liquids and gases; PA1 (i) To provide a HVP in which the speed and siphon-elevation limits of priming action may be primarily controlled by adjusting the pump-priming inlet orifice size; and PA1 (j) To provide a HVP that assures such reliable and convenient siphon operation that siphons with gravity-powered flow can replace energy-consuming pump-powered flow in many new uses that will each result in savings of non-renewable energy resources.
In all of the prior art found, there is a clear and consistent need for a more simple, reliable, controllable and versatile siphon-priming method.


The invention relates to a belt tightening drive for tightening a safety belt which can be wound up around a winding shaft, said belt tightening drive comprising an electric motor, a spindle shaft and a output wheel coupled with the winding shaft and a worm gear, by way of which the output wheel is driven by the spindle shaft, wherein for the formation of the worm gear an external helical gear of the output wheel is combing with a worm drive supported torsionally rigid on the spindle shaft and it is provided according to the invention that the external gear of the output wheel comprises at least two gear sections, wherein a first gear section comprises a gear with constant geometry and a following second gear section is designed with an increasing root circle diameter and/or increasing tip circle diameter and/or increasing tooth thickness.

1. Field of the Invention
The invention relates to a belt tightening drive for tightening a safety belt which can be wound up around a winding shaft.
Said type of reversible belt tightening drive is disclosed for example in DE 10 2008 048 339 A1, in which an electric motor is driving a spindle shaft by way of a first gear designed as a spiral gear, said spindle shaft in turn driving an output wheel by way of a second gear, said output wheel being arranged torsionally rigid on a winding shaft for winding up a safety belt. Said second gear is formed by a worm drive arranged on the spindle shaft and an external helical gear of the output wheel.
A reversible belt tightener is activated when necessary, i.e. for example in connection with a minor crash or an impending crash, during off-road journeys and in connection with braking deceleration of the vehicle which brings about the tightening of the safety belt. To maintain the belt tightening in these kinds of situations, a high electric current is used to energize the electric motor which causes an undesirably high strain on the vehicle's supply system.
In the event of a crash, the belt tightener is activated pyrotechnically and represents a full-load tightening resulting in the decoupling of the belt tightener from the electric motor. As a result of the subsequent holding of the safety belt by means of the electrical drive with the residual energy of the electric motor, it is re-coupled onto the belt tightener which can potentially cause impairments in the power limit.
Moreover, said residual energy of the electric motor causes a strain on the vehicle's supply system.
Furthermore, highly dynamic load statuses develop in connection with full load tightening. They result in high turning moments (holding moments) in the output stage of the belt tightener and hence in high gear tooth forces, in particular also in high axial forces in connection with the helical gears of the used gear components, said axial forces causing a deformation of the gear components such as the wheel body and the bearings in the housing of the belt tightener. This means a loss of engagement depth and causes axial relative shifts in the engagement of the gear components, as a consequence of which the active gear width is reduced considerably. The two negative effects result in a substantial reduction of the carrying capacity of the gear components. Moreover, high radial forces develop due to the engagement angle, resulting in shifts and deformations in consequence of which the engagement depth (active depth of teeth) and hence the coverage is reduced. This means a loss in carrying capacity and ultimately leads to damage and mechanical failure of the gearing components.


A solid electrolyte, a method of manufacturing the same, and a lithium battery and a thin-film battery that employ the solid electrolyte are provided. The solid electrolyte contains nitrogen to enhance the ionic conductivity and electrochemical stability of batteries.

This application claims priority from Korean Patent Application No. 2002-74362, filed on Nov. 27, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a solid electrolyte and a battery employing the solid electrolyte, and more particularly, to a solid electrolyte with improved ionic conductivity and electro-chemical stability and a lithium battery and a thin-film battery that employ the same.
2. Description of the Related Art
With rapid advance in computer technology and the mobile communications field, the development of digital, smaller, and multimedia information devices have been accelerated. Lithium batteries, which are lightweight and have high energy density, are taking the initiative in the market as an energy source of typical portable information devices, such as notebook personal computers, personal digital assistants (PDAs), mobile phone terminals.
The size of batteries can be a limiting factor to the minimization of such electronic information devices. For example, the size of complementary metal oxide semiconductors (CMOS), smart integrated circuits (ICs), micro-sensors, micro-robots are limited by the size of their battery. Based on the advances in semiconductor manufacturing processes and micro-electro mechanical systems (MEMS), the use of thin-film batteries as an energy source for next-generation micro-systems is expected to increase.
FIG. 1 shows the structure of a conventional thin-film battery. Referring to FIG. 1, a conventional thin-film battery basically includes a cathode 12, an electrolyte 14, and an anode 13, which are sequentially deposited as films on a current collector 11. The conventional thin-film battery has a thickness of about 10 μm.
Since the anode 13 is arranged close to the cathode 12, the conventional thin-film battery has advantages of higher current density, higher battery efficiency, and shorter migration distance of ions. Since ions can migrate across the battery more easily and rapidly, the amount of reactants can be cut down greatly. Another advantage of the conventional thin-film battery is that it is easier to vary the shape and size of batteries for particular purposes. Therefore, thin-film batteries are considered to be the most promising main power source for micro-electronic devices, MEMS devices, micro-sensors.
Thin-film batteries are manufactured by the same method as semiconductor manufacturing processes. Accordingly, a thin-film battery may be mounted as a back-up power source along with electronic circuits in a semiconductor chip such as a complementary metal oxide semiconductor memory chip. In other words, the dead space of electronic devices can be minimized with maximum space utilization efficiency when a thin-film battery is incorporated. Various batteries with different voltage and capacitance can be implemented through proper designing and etching for serial and parallel connections, and thus they have wide applications.
Unlike conventional lithium ion batteries, thin-film batteries require a perfect solid Li+ conducting electrolyte. Electrolyte materials, such as LiSiCON, Li4SiO4—Li3PO4 solid solution, Li2O—B2O3—SiO2,Lipon ( lithium phosphorous oxynitride), etc. are considered to be suitable for thin-film batteries.
Although the above-listed crystalline solid electrolytes are known as having effective Li+ conductivity, inorganic compounds with complex crystalline structure are amorphous when deposited as a thin film and require high temperature thermal treatment for crystallization. Therefore, it is impractical to apply such inorganic compounds to manufacture thin-film batteries.
In contrast, glass electrolytes with high isotropic conductivity in amorphous state are easier to process into thin film form compared to crystalline electrolytes. The ionic conductivity of glass electrolytes varies depending on their composition, and the composition of thin film electrolytes can be easily adjusted during deposition. In addition, in thin-film batteries whose electrodes are spaced merely several micrometers apart, as low ionic conductivity as 10−7 S/cm is satisfactory for battery formation. Therefore, the comparatively low ionic conductivity of glass solid electrolytes is not important in thin-film batteries.
The currently most attractive solid electrolyte for thin-film batteries is Lipon, which is disclosed by John B. Bates et al. in U.S. Pat. No. 5,338,625, entitled "Thin film Battery and Method for making the Same." The LiPON solid electrolyte, which is manufactured with a Li3PO4 target by radio frequency sputtering in a nitrogen atmosphere, has a high ionic conductivity of 2(±1)×10−6 S/cm. In addition, the Lipon solid electrolyte forms a very stable interface with an anode or a cathode and allows the battery to less deteriorate during operation. The Lipon solid electrolyte satisfies most requirements for use in thin-film batteries employing a solid electrolyte.
However, the properties of the Lipon thin film are greatly dependent on processing parameters for thin film formation and the Lipon thin film lacks reproducibility (P. Birke et al., Materials for thin film batteries for application in silicon technology, Solid State Ionics 93 (1997), 1–15). For this reason, considerable time is required to solve such above-described problems before Lipon thin films can be mass produced.
Therefore, for the development of thin-film batteries as a powerful energy source of 21st century leading micro-systems, it is essential to develop glass solid electrolytes with improved ionic conductivity.

Solid electrolyte and battery employing the same


A novel optical time division multiplexing (OTDM) module based on hybrid-integrated optical chips is disclosed. An integrated modulator chip generates optical RZ signal streams which are then interleaved in an integrated time-delay chip to produce an OTDM signal. The integrated modulator chip is coupled and secured to the integrated time-delay chip via a suitable optical index-matching layer or collimating lenses. Such an approach alleviates the stability problems offered by conventional fiber-based OTDM technology and aids in reducing the size and complexity as well as lowering the cost for the assembly. Furthermore, the time-delay chip of the present invention offers fine tuning capabilities thereby allowing for slight adjustments in the interleaving of optical signal streams when non-standard data transmission rates are required.

In general, there are two common data formats for the transmission of high-speed digital data. Non-Return-to-Zero (NRZ) signal format is the more popular of the two formats due to its inherent simplicity. In this particular format, each "0" or "1" data bit is represented by a low or high signal level, respectively, lasting an entire clock period. However, with ever-increasing data rates, especially in optical transmission systems, Return-to-Zero (RZ) signal formats are becoming the transmission format of choice. In RZ modulation format, each data bit occupies only a portion of the clock period creating a distinct transition between adjacent bits and, thereby, producing a cleaner optical signal for the receiver to read. For high-rate (>10 Gbit/s) or ultra-long-haul (>1000 km) transmission, the RZ modulation technique is now coming into vogue as it affords certain efficiency gains such as higher signal-to-noise ratio (SNR) and lower crosstalk amongst adjacent bits. In this way, bit-error-rate (BER) may be improved. RZ encoding also offers better immunity to fiber nonlinear effects and the effects of polarization mode dispersion (PMD), factors which can limit long-haul or high-rate transmission severely. Optical transmission based on OTDM technology uses the RZ format primarily because of the relative ease it affords for multiplexing in the optical time domain.
The explosive growth of the Internet, and the corresponding demand for bandwidth has necessitated the introduction of optical time division multiplexing (OTDM) technology. The bandwidth of electrical components currently used for multiplexing and routing is rapidly being pushed to its fundamental physical limit. With the tremendous growth in data traffic predicted over the next few years, OTDM technology will be needed to avoid the potential electronic bottleneck that these multiplexers and routers will impose upon the next generation Internet.
In today's optical backbone network, dense wavelength division multiplexing (DWDM) enables high capacity transmission by combining multiple optical carriers on a single fiber. Each carrier or wavelength is modulated with a data channel having a rate up to, for example, 10 Gbps. In this way, the electronic bottleneck may be alleviated by shifting the electrical multiplexing to the optical spectral domain. However, the operation and management of DWDM systems is highly complicated and costly. Accordingly, single wavelength systems with higher data rates e.g. 40 or 80 Gbits/s are resurfacing as an alternative to DWDM systems in order to maintain the same total capacity. Single wavelength channels with higher rates could be multiplexed together to form a higher capacity DWDM system. Therefore, a key issue is to achieve higher rates per single optical channel which cannot be achieved by electrical time division multiplexing (ETDM) technology. OTDM technology is used for achieving higher rate per single channel in the optical domain.
In optical transmission systems, the bit rate is rising continuously. Target values for the future are on the order of 40 to 80 Gbit/s. With known transmitter combinations of semiconductor lasers with external modulators, such target values are attainable only with great difficulty. However, signal streams generated by individual transmitters may be combined in an optical time division multiplexer to make a signal stream with a higher bit rate.
The fundamental premise of OTDM technology is to solve the bandwidth bottleneck problem that ETDM technology is not currently able to address. ETDM technology is based on a traditional scheme of multiplexing individual lower-rate electronic signals into a high-speed serial electronic signal. The high-speed serial electrical signal may then be converted to an optical signal using a directly modulated laser or external modulator. These methods have worked well for data transmission rates up to 40 Gbit/s. However, electrical components for ETDM technology such as electrical multiplexers and demultiplexers (EMUXs and EDMUXs), that can achieve the high data rates (e.g. work beyond 40 Gbit/s) required today, are not expected to be available for the next several years.
On the other hand, OTDM technology makes the implementation of 80 Gbit/s, 160 Gbit/s or even higher capacity systems more achievable as compared to their electrical counterparts. In this lies the biggest advantage of OTDM technology. OTDM also opens the door for higher-rate nonlinear optical transmission such as, for example, soliton transmission which may make it possible to achieve transmission rates as high a 160 Gbit/s for very long distances without regeneration.
OTDM technology is based on a purely optical method for achieving very high data rate systems. For example, to generate an 80 Gbit/s RZ data stream, a 40 GHz clock pulse with, say, a pulsewidth of 6 picoseconds is first generated. Two sets of four 10 Gbit/s NRZ electrical signals may then be multiplexed via 4:1 EMUXs to form two 40 Gbit/s NRZ signal streams. The two 40 Gbit/s NRZ signal streams may then be applied to two corresponding external optical modulators to gate the incoming 40 GHz RZ clock pulses. In this way, the NRZ electrical signals are converted to RZ optical signals. One of the two 40 Gbit/s optical RZ signal streams may then be delayed by half a clock period to allow for interleaving in the time domain. The two 40 Gbit/s optical RZ signal streams may then be combined to form the final 80 Gbit/s optical RZ data stream.
The advantage of OTDM technology is that it alleviates the bandwidth bottleneck that ETDM technology is not able to currently address. Furthermore, the data received after transmission is of a better quality than that achieved through ETDM techniques. For example, generation of a 40 Gbit/s signal can easily be achieved through OTDM by applying two 20 Gbit/s NRZ electrical signal streams on an optical multiplexer (OMUX) e.g combination of two amplitude modulators and then delaying one optical data stream 25 ps relative to the other. Interleaving these two signal streams will then produce a 40 Gbit/s signal.
However, there is a downside to OTDM technology as well. Specifically, current OTDM implementations are relatively more complicated, expensive, and bulky than their counterpart ETDM solutions which normally just consist of integrated electronic chips. SO even though it's easier to get to 40 Gbit/s systems using OTDM technology today (because 40 Gbit/s electronics have not been fully developed), these are not very easy systems to build and manage. Even so, for data rates greater than 40 Gbit/s, OTDM technology is definitely the technology of choice in that it satisfies important transmission requirements e.g. minimal chromatic dispersion, reduced polarization mode dispersion and reduced impact of fiber non-lineararaties.
Today, 40 Gbit/s ETDM systems are, in fact, emerging. Compared to current OTDM implementations, ETDM is generally more compact and cost effective due to processing technology available for electronic chip integration. However, for higher rate (e.g. 80 Gbit/s) and long-haul transmission requiring minimal chromatic and polarization mode dispersion, the use of OTDM technology is more effective than ETDM.
Existing approaches for OTDM implementation are based on fiber optics and discreet electro-optic components. For example, the optical clock pulse described above may be divided amongst the two modulators via a fiber coupler and the delay required for interleaving may be realized by using fiber of differing lengths. The two RZ optical signal streams may then be combined, again using a fiber coupler, These kind of approaches are rather expensive and bulky and face stability and processing problems.

Hybrid-integrated high-speed OTDM module


A circulation filter mounting structure in a disk drive including a housing having a base and a cover fixed to the base, a disk as a storage medium rotatably contained in the housing, and a head contained in the housing for recording and reproducing data on the disk. The circulation filter mounting structure includes a wall provided between an outer circumference of the disk and an inner surface of the housing, for partially blocking an air flow generated by rotation of the disk, the wall extending in a direction substantially perpendicular to a radial direction of the disk, and a filter mounted between the wall and the inner surface of the housing, for collecting dust.

1. Field of the Invention
The present invention relates to a circulation filter mounting structure in a disk drive such as a magnetic disk drive or an optical disk drive.
2. Description of the Related Art
In general, a magnetic disk drive for a computer adopts a contact start and stop (CSS) system defining a relation between a magnetic head and a magnetic disk facing it. In this system, while the disk is being rotated, the head is kept flying from the disk at a microscopic height owing to the balance between a flying force applied to the head by an air flow generated by high-speed rotation of the disk and an elastic force of a spring arm pressing the head on the disk.
In such a magnetic disk drive, if dust is present inside the disk drive, the dust enters a gap between the magnetic head and the magnetic disk during rotation of the disk to cause read error or in the worst case, may cause head crash. To cope with this problem, the magnetic disk drive employs a breather filter for preventing entry of dust from the outside of the disk drive and a circulation filter for collecting dust generated inside the disk drive.
Referring to FIG. 7, there is shown a top plan view of a conventional magnetic disk drive having such a circulation filter under the condition where a cover (not shown) is removed. Reference numeral 12 denotes a housing (enclosure) composed of a base 14 and the cover. A spindle hub to be rotatably driven by an inner hub motor (not shown) is provided on the base 14. A plurality of magnetic disks 20 and spacers (not shown) are alternately stacked and mounted on the spindle hub. That is, the plurality of magnetic disks 20 are regularly spaced from each other and are fixedly mounted on the spindle hub by securing a disk clamp 18 to the spindle hub by screws.
Reference numeral 22 denotes a rotary head actuator composed of an actuator arm assembly 26 and a magnetic circuit 28. The actuator arm assembly 26 is rotatably mounted on a shaft 24 fixed to the base 14, and has a plurality of actuator arms 30 extending in one direction from the center of rotation. A spring arm 32 supporting a magnetic head 34 is fixed to one end portion of each actuator arm 30.
Reference numeral 36 denotes a flexible printed circuit sheet (FPC) for taking out a signal from each magnetic head 34. The flexible printed circuit sheet 36 is fixed at its one end to the actuator arms 30 and is connected at the other end to a connector 38. A circulation filter 40 is provided in the vicinity of the head actuator 22 where dust tends to be generated, so as to immediately collect the dust generated.. However, in such a conventional structure having the circulation filter 40 located at that position, an air flow generated by the rotation of the disks 20 is disturbed by the head actuator 22 located upstream of the circulation filter 40 in respect of the flowing direction of the air flow, and becomes stagnant before the filter 40. Accordingly, the dust cannot be efficiently filtered off by the filter 40. Further, as large spaces are present on the right and left sides of the filter 40, the air partially flows through these large spaces without being passed through the filter 40. Accordingly; the dust contained in the air flow is not filtered off by the filter 40.
Referring next to FIG. 8, there is shown another conventional magnetic disk drive which has seen increased use in recent years. The magnetic disk drive shown in FIG. 8 employs a circulation filter 40' located at a position opposite to the head actuator 22 with respect to the center of the magnetic disks 20. The circulation filter 40' is mounted in such a manner that the filter 40' is attached to a resin molding frame and the frame is fitted with the base 14 or the cover. Owing to this location of the circulation filter 40', an air flow generated by the rotation of the magnetic disks 20 steadily advances along the inner wall surface of the base 14 and is efficiently directed toward the circulation filter 40' as shown by an arrow A in FIG. 8. Accordingly, more dust can be collected per unit time in comparison with the prior art shown in FIG. 7.
However, yet in the prior art shown in FIG. 8, an air flow shown by an arrow B acts so as to reverse an air flow shown by an arrow C passing through the filter 40'. As a result, the air flow C passing through the filter 40' is decreased in quantity by a reverse flow component, thus reducing a dust collection efficiency..

Circulation filter mounting structure in disk drive


A system and method for isolating and automating the transfer of tax withholdings to the appropriate tax withholding accounts. A check is provided which on its face indicates the withholding accounts and amounts withheld for each withholding account. The Payroll Trust Check (PTC) is unique in that it clears the banking system with multiple payees. Other than the employee portion (net amount), these payee amounts are accumulated in trust accounts and forwarded to the U.S. Treasury and/or other collection agencies on a daily basis. A sequence of bar codes are also printed on the check to identify the particular withholding accounts. When the check is presented for processing, the information on the front of the check is micro-coded, as is normally the case. The additional information related to the withholding accounts and amounts are also micro-coded. The check is optically scanned to read the micro-coded data and the bar code data. On the basis of the bar code data, which includes the employer's account number, a processing computer determines the actual destination to which the withholding amounts are to be electronically transferred into the proper withholding account.

The current methods of tax revenue collection are susceptible to nonpayment, delays, and errors, and make it quite difficult to reconcile withholdings. The actual transfer of funds representing withholding amounts, whether transferred electronically or by mail, often does not occur or is delayed days or even months after a payroll check is issued and the tax withheld. This nonpayment and/or time lag is accountable for 50 to 100 billion dollars in tax revenue loss per year to the U.S. Treasury.
The payroll check has been in widespread use for almost 50 years. It provides a mechanism for most employers to disburse their payroll efficiently. The employer computes the employee's net pay, which is the gross pay less deductions for items such as FICA, federal income tax, state income tax, local income tax, insurance premiums, retirement deductions, etc., and records these amounts on a standard payroll check stub. The payroll check contains only the net amount (gross amount earned by the employee less all deductions).
Banks collect and transfer federal withholding tax payments from employers. The employer or their designated agent fills out a particular Internal Revenue Service (IRS) form. This IRS form and check for the amount specified on the form are "deposited" at a Federal Reserve Bank or a designated bank. The withheld funds have a due date defined according to a complicated schedule depending on the size of the business and other factors.
The funds for federal income tax withholdings are transferred electronically to the New York Federal Reserve Center and the information on the IRS forms are electronically forwarded to the IRS Headquarters in Washington, D.C. The information on the forms forwarded to Washington must be reconciled with the funds electronically transferred to the New York Federal Reserve Center. Reconciliation is performed in the aggregate. No independent sources are checked to determine the accuracy, completeness or timeliness of the deposited federal income tax withholding information for individual taxpayers. In some instances, such as for the payroll of large corporations, intermediate parties process the forms and deposit the funds for the employer into the Federal Reserve bank system.
The state government income tax collection agencies use similar procedures as the federal government, and suffer similar nonpayment and/or delayed payment problems.
In addition, the IRS collects up to 11 different types of withholding, from standard income tax withholding and FICA to Railroad Retirement and Federal Retirement amounts. To make these transfers, the IRS requires a specific 7 data item format for electronic transfer of the withheld amounts and account numbers depending on which type of tax the withholding amount represents.
The present invention is designed to simplify the tax withholding procedure and consolidate it into a single computer transaction for each employer on a daily basis.
There are very few systems and methods for multiple payees known. U.S. Pat. No. 1,198,936 and U.S. Pat. No. 1,240,255 relate to a multiple payee, carbon paper-based deposit slip. All of the payees denoted on the multiple payee slip must belong to the same financial institution for the deposit slip to be effective. This type of device has very little practical application in the computerized society of today. Moreover, the deposit slip does not embrace the allocation and/or payment of withholding taxes and is not negotiable between banks or financial institutions.
There is no system or method heretofore known in which computer processing, image processing and telecommunications are employed to achieve multiple account transfers of taxes and other withholdings from a single payroll trust check.


An information recording control apparatus in a camera is provided with reproducing means for reproducing information pre-recorded on film, recording means for recording information on the film, evaluation means for evaluating a state in which a signal is recorded on the film on the basis of the output state of the reproduction signal by the reproducing means, and control means for setting the recording condition of the recording means in conformity with the result of the evaluation by the evaluation means. The evaluation means evaluates the reproduction signal when the reproducing means reproduces the information pre-recorded on the film, and the control means sets the recording condition of the recording means in conformity with the result of the evaluation.

1. Field of the Invention
This invention relates to an information recording control apparatus in a camera for recording photographing information on film.
2. Related Background Art
An information recording apparatus in a camera for recording information regarding photographing (photographing information) on a magnetic recording medium applied to film is known (see U.S. Pat. No. 4,864,332).
It is conceivable that by using such a recording apparatus, for example, the speed information of film is pre-recorded on the film and a camera reproduces and utilizes it or photographing information such as trimming information is recorded on film for each photographing frame thereof and is reproduced in the step of stretching out the film and the stretching-out process is carried out on the basis of said information. It is also conceivable to pre-record exposed frame information, reproduce it by a camera itself and position an unexposed frame at a predetermined photographing position during the feeding of film.
Accordingly, the information recorded on the film must be recorded stably at a signal level of a range suited for reproduction.
However, there is the problem that if a gap exists between a recording head and the film or the recording film is inclined with respect to the recording track of the film when information is recorded on the film, a corresponding loss will occur in recording and stable information recording cannot be accomplished at a signal level of a desired range.

Information recording control apparatus in a camera


Cables have dielectric armors with armor profiles that provide additional crush and impact resistance for the optical fibers and/or fiber optic assembly therein, while retaining flexibility to aid during installation. The armored cables recover substantially from deformation caused by crush loads.

Fiber optic cables and assemblies should preserve optical performance when deployed in the intended environment while also satisfying any other requirements for the environment. Indoor cables for riser and/or plenum spaces, for example, may require certain flame-retardant ratings as well as mechanical requirements. Mechanical characteristics such as crush performance, permissible bend radii, and temperature performance in part determine how installation and use of the cable in the installation space affect optical performance of the cable.

Armored fiber optic assemblies and methods of forming fiber optic assemblies


Failures in a fault-tolerant computer system which includes two or more input/output processors connected to a data communication system are detected by monitoring data communication. The computer system is able to detect failures associated with a primary input/output processor, as well as with a standby input/output processors, and is also able to discriminate between failures of the input/output processors and communication failures in the data communication network itself. In addition to using heartbeat-like transmissions, various other categories of data communication are also used to detect failures. The system is able to detect failures when the input/output processors are on a common network segment, allowing the processors to monitor identical data traffic, as well as when the processors are on different segments where, as a result of filtering behavior of network elements such as active hubs, the processors may not be able to monitor identical data traffic.

This invention relates to the detection of failures, such as communication failures, in a fault-tolerant computing system.
Redundant hardware elements are commonly used in fault-tolerant computing systems. Individual elements of the system typically attempt to detect faults by monitoring signals generated by other elements in the system or generated externally to the system.
In addition, an element of the system may periodically transmit a so-called "heartbeat" signal that indicates proper operation of the element. If the heartbeat signal is not received by another element in the system, the receiving element can suspect that the transmitting element is not operational. However, failure to receive a heartbeat signal also may result from a fault in the communication path between the two elements. In general, fault handling should distinguish between a fault in an element of the system and a fault in the communication path between elements.
Redundant network interface controllers (NICs) are used in fault-tolerant computing systems to provide reliable, uninterrupted communication with an external network. In general, one NIC operates in a primary, or active, mode in which the NIC is responsible for communication with other devices on the network, while the other NIC operates in a standby mode.
In operation, the NICs can exchange heartbeat messages to detect failures in a path from one NIC through the external network and back to another NIC. A failure in the path between NICs can occur at several points, including the input or output stages of the NICs, the transmitting or receiving connections between the NICs and the external network, or in the external network itself. The point of connection to the external network is generally at a port of a network hub, with the hub being connected to multiple network devices. Each NIC may be connected to a different hub in the external network to avoid having a single hub become a critical point of failure.


A method and apparatus for routing a message for a Proximity-based Service (ProSe) by a User Equipment (UE) in a wireless communication system is provided. The method includes sending, to a server, an authorization request message requesting authorization for ProSe usage by an application installed in the UE, the authorization request message including an application ID (ID) for identifying the application and a UE ID for identifying the UE; and receiving an authorization response message including a validity time for a ProSe of the application from the server in response to the authorization request message.

1. Field of the Invention
The present invention relates generally to a method and apparatus for routing a message for a Proximity-based Service (ProSe) in a wireless communication system.
2. Description of the Related Art
With the development of communication devices and communication systems, users of the communication devices require services by which they can easily obtain or share their desired information at any time. Recently, due to the advent of smart phones and tablet Personal Computer (PCs), an environment has been provided, in which users can obtain and share a variety of information through wireless communication.
However, a wireless communication system may not enable users to obtain and share their desired information, without proper communications infrastructure. In addition, it is difficult for the wireless communication system to efficiently provide real-time information, due to system complexity or the time delay.
Accordingly, a Device to Device (D2D) communication service has emerged, which enables terminals (also known as User Equipments (UEs)) to perform communication services with each other through a direct communication link without network entities such as a base station (also known as an evolved Node B (eNB)) in areas in which there is no communications infrastructure.
At present, however, it is not possible to provide various types of D2D communication services since the systematic message routing for performing D2D communication services has not been defined.
The above information is presented as background information only to assist with an understanding of the present invention. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.

Method and apparatus for routing proximity-based service message in wireless communication system


Improvement in assays utilizing at least hydrogen peroxide for one analysis reagent is provided. The assay of the present invention employs a stable hydrogen peroxide adduct in dry state which has no adverse effects on the assay, and which has a high hydrogen peroxide-retaining ability. In the assay, an aqueous solution is added to an adduct in dry state of (a) at least one member selected from the group consisting of a carboxylic acid and a salt thereof, phosphoric acid and a salt thereof, and a sulfonic acid and a salt thereof, and (b) hydrogen peroxide to generate peroxide, and the thus generated peroxide is used for the analysis reagent.

This invention relates to an assay wherein hydrogen peroxide is used as an assay reagent, and wherein hydrogen peroxide in a stable, dry hydrogen peroxide adduct form is used without inducing any adverse effects on the assay principle.
Typical assays wherein peroxide is used as an assay reagent are chemiluminescence assays. For example, in a chemiluminescence reaction known as peroxalate chemiluminescence, a high energy intermediate is generated from an oxalic acid derivative and hydrogen peroxide in the presence of a basic catalyst, and a fluorescent reagent is excited by the resulting energy to thereby induce luminescence. In the case of a luminol derivative, it is oxidized by hydrogen peroxide in the presence of Fe(CN).sub.6.sup.3-, microperoxidase, or peroxidase to result in the excited state of aminophthalic acid, and the luminescence occurs upon returning of the excited aminophthalic acid to its ground state. An acridinium derivative also undergoes luminescence with the addition of hydrogen peroxide. Such chemiluminescence reactions are widely used in various assays including those based on a specific binding reaction, and in such assays, the luminescence compound or the catalyst (such as enzyme) for the luminescence reaction is incorporated as a label. Hydrogen peroxide is also incorporated in such assay as a reagent indispensable for inducing the luminescence. The chemiluminescence reactions as described above exhibit a relatively high sensitivity, and therefore, these reactions are widely employed for the assays in various fields including clinical tests and environmental tests.
The assays wherein hydrogen peroxide is used as an assay reagent are not limited to the chemiluminescence assays. Peroxidase enzymes such as horseradish peroxidase (hereinafter referred to as HRPO) and microperoxidase are also used for the catalyst of color development reactions and electrochemical reactions. HRPO is used for the labeling enzyme in many assays including enzyme immunoassays, nucleic acid hybridization assays, and immunohistostaining assays wherein a tissue or cells are stained with a labeled antibody specific therefor, and in such assays, hydrogen peroxide, which is the substrate for the HRPO, is used as an assay reagent. Hydrogen peroxide is also used in occult blood test of feces wherein peroxidase activity of hemoglobin in feces is detected by color development reaction and hydrogen peroxide is added as the substrate of the enzymatic reaction. Other catalysts having peroxidase activity include ions and cheletes of a metal, porphyrin derivatives, catalyst antibodies, and the like, and these catalysts are also used in various assays wherein peroxide is used as an assay reagent as in the case of the enzyme catalysts as described above.
Recently, MEDIA (mediator diffusion-controlled immunoassay) has been disclosed as a specific binding assay wherein a signal substance generator such as an enzyme is used for the labeling agent to be developed through the matrix with the liquid sample; and the labeling agent is allowed to form a distribution of a particular profile in terms of the distance of the labeling agent from the detection port by the specific binding reaction between the analyte in the liquid sample and the specific binding substance; and the current corresponding to the analyte concentration of the liquid sample which is controlled by diffusion of the signal substance such as an electron mediator generated from the labeling agent is measured to thereby determine the concentration of the analyte. (See Japanese Patent Application Laid-Open No. 5(1993)-264552(EP 0 525 723 A2) and Japanese Patent Application Laid-Open No. 7(1995)-234201.) In MEDIA, HRPO is again used for the labeling agent in view of its high sensitivity as an oxidoreductase, and hydrogen peroxide is used in combination with the HRPO as the substrate for the label enzyme HRPO.
In the wide variety of assays as described above, the principle that a reaction specific for the analyte is detected by utilizing hydrogen peroxide has been adopted as would be appreciated from the foregoing description. A process capable of providing the hydrogen peroxide in stable, dry state without inducing any adverse effect on the assay principle is urgently required both for the convenience of the assay procedure and for the stability of the assay reagent.
Conventional means of retaining the hydrogen peroxide in dry state include dried urea-hydrogen peroxide adduct (Hyperole) and dried sodium carbonate-hydrogen peroxide adduct. These adducts are used in other fields as a bleach, a cleaner, a hair dye, and the like. The hydrogen peroxide adducts with urea and sodium carbonate are highly moisture absorptive and unstable, and could not endure long-term storage. Furthermore, urea is a compound which is well known as a denaturing agent of proteins, and accordingly, suffered from the defects that its use resulted in adverse effects when used in the assays as described above wherein proteins were involved as the analyte or assay reagents. Sodium carbonate also suffered from the detect of the high pH after its dissolution, and such defect inhibited its use in the assay purposes.
The MEDIA (mediator diffusion-controlled immunoassay) as described above is a specific binding assay provided with the feature of a dry chemistry assay wherein no washing operation is required and the assay can be conducted by merely adding the liquid sample to the assay device. In the MEDIA device described in Japanese Patent Application Laid-Open No. 7(1995)-234201, hydrogen peroxide in dry state was incorporated in the assay device in the form of urea-hydrogen peroxide adduct. In this device, however, the urea-hydrogen peroxide adduct in dry state had to be located at the downstream end of the assay device to prevent the adverse influence of urea on the antigen-antibody reaction and the enzyme reaction. Due to such remote location of the urea from the reaction site, a considerable time period was required for the establishment of stable response and quick measurement could not be realized in spite of the various measures taken for the promotion of natural diffusion of the hydrogen peroxide back to the reaction site. In addition, despite such remote location of the urea-hydrogen peroxide adduct from the reaction site, the assay device still suffered from inhibitory effects on the specific reaction of the urea that reversely diffused along the flow path after a while.

Assay utilizing hydrogen peroxide adduct


Methods for preparing waterborne heat seal coating compositions are disclosed, including (A) melt blending an ethylene vinyl acetate copolymer, a tackifier, and a wax in a first mixing apparatus to form a melt blend, (B) contacting the melt blend with an initial aqueous stream comprising a neutralizing agent, water, and a surfactant in an emulsification zone of the second mixing apparatus to form a dispersion, and (C) diluting the dispersion with water in a dilution zone of the second mixing apparatus to form the waterborne heat seal coating composition. Methods for preparing waterborne heat seal coating compositions are also disclosed, including (A) melt blending an ethylene vinyl acetate copolymer, a tackifier, and a wax in a mixing and conveying zone of a mixing apparatus to form a melt blend, (B) contacting the melt blend with an initial aqueous stream comprising a neutralizing agent, water, and a surfactant in an emulsification zone of the mixing apparatus to form a dispersion, and (C) diluting the dispersion with water in a dilution zone of the mixing apparatus to form the waterborne heat seal coating composition, wherein the length-to-diameter ratio of the extruder mixing apparatus is greater than or equal to 12 to 1. Waterborne heat seal coating compositions prepared according to the disclosed methods are also disclosed.

Heat seal coatings have been used in food, pharmaceutical, medical, and industrial packaging applications. Examples of heat seal coating products include ethylene vinyl acetate ("EVA") heat seal coatings which can be water-based dispersions based on high molecular weight ethylene interpolymers. Commercially available examples of such water-based products include those sold under the name ADCOTE™ 37 series, available from The Dow Chemical Company.
Waterborne heat seal coating products are typically manufactured by a batch dispersing process, which has relatively high conversion cost due to long cycle time as well as substantial batch-to-batch variations in the produced dispersions. In addition, significant waxes are required as process aids in the batch dispersion process in order to help dispersibility and reduce the melting viscosity of the mixture even though the waxes do not contribute to the adhesion properties. Additionally, the ethylene vinyl acetate resin is likely to be subject to hydrolysis in the batch dispersing process due to longer processing in a strong base environment at high temperature, which will result in degradation of the EVA polymer and performance reduction of heat seal coatings. Accordingly, a continuous dispersion process with short residence time can be preferable to mitigate ethylene vinyl acetate resin hydrolysis.
More recently, and with the limitations of batch processes in mind, waterborne heat seal coatings have been produced by continuous processes in which a single extruder is used to blend, emulsify, and dilute the final dispersion. However, continuous processes have surprisingly encountered scalability issues on large, commercial-scale extruders where the final product is not sufficiently dispersed, i.e., non-uniform dispersion of a narrow particle size distribution, resulting in an unstable dispersion product. This is likely a consequence of the difference in melting temperatures of the raw materials used to produce the dispersions. That is, the lower melting point materials, upon first melting in the extruder at low temperatures, lubricate the pellets of higher melting point materials, thereby preventing the formation of a homogenous mixture of the formulation required for producing a uniform dispersion of a narrow particle size distribution. Accordingly, methods for efficiently and effectively producing a uniform, aqueous dispersion suitable for use in heat seal coating applications, while still maintaining or improving quality and waterborne heat seal coating performance, is desirable.
Methods for manufacturing waterborne heat seal coating products are disclosed. In some embodiments, the methods comprise pre-compounding or pre-mixing at least a portion of the components of the waterborne heat seal coating compositions. For instance, in some embodiments, the disclosed methods comprise (A) melt blending an ethylene vinyl acetate copolymer, a tackifier, and a wax in a first mixing apparatus to form a melt blend, (B) contacting the melt blend with an initial aqueous stream comprising a neutralizing agent, water, and a surfactant in an emulsification zone of the second mixing apparatus to form a dispersion, and (C) diluting the dispersion with water in a dilution zone of the second mixing apparatus to form the waterborne heat seal coating composition.
In some embodiments, the first mixing apparatus is an internal batch mixer, such as a BANBURY™ mixer. In some embodiments, the first mixing apparatus is an extruder, such as a twin-screw extruder. In some embodiments, the second mixing apparatus is an extruder, such as a twin-screw extruder. In some embodiments, the second mixing apparatus is a rotor stator mixer. In still other embodiments, the process is carried out in a single, highly efficient mixing apparatus, such as an extruder, wherein the extruder has particular length-to-diameter ratios to achieve a uniform dispersion.
In some embodiments, the methods for preparing a waterborne heat seal coating composition comprise (A) melt blending an ethylene vinyl acetate copolymer, a tackifier, and a wax in a mixing and conveying zone of an extruder mixing apparatus to form a melt blend, (B) contacting the melt blend with an initial aqueous stream comprising a neutralizing agent, water, and a surfactant in an emulsification zone of the extruder mixing apparatus to form a dispersion, and (C) diluting the dispersion with water in a dilution zone of the extruder mixing apparatus to form the waterborne heat seal coating composition, wherein the length to diameter ratio of the extruder mixing apparatus is greater than or equal to 12 to 1.
Waterborne heat seal coating compositions produced by the methods of the disclosure are also disclosed, as are articles, such as food packaging articles, comprising the disclosed waterborne heat seal coating compositions.


An escalator or moving sidewalk exhibits a frame for the formation of a supporting structure between entry and exit that is made at least partially of perforated plate, with the holes in particular being provided over a significant part of the frame height, preferably roughly one half the frame height.

The invention relates to an escalator or moving sidewalk.
It has been known for a long time that escalators and 10 moving sidewalks must exhibit frames to ensure support for the step or pallet band between entry and exit.
Corresponding chain rollers and step rollers typically each run on separate rails supported by a frame made of sections. In order to form the required step pattern or to provide the desired pallet band, the rails have to run at a given height and be supported safely and in particular also rigidly there. If the rail were to bend too much, not only would the passenger be given a feeling of insecurity, there would also be a risk that in the event of an asymmetric load of the step or pallet band, the specified clearance would be exceeded so that the step or pallet would scrape on the rail.
It is therefore important that the frames used are particularly rigid and do not bend beyond the given tolerances even in the event of the maximum permissible operating load of the escalator, but also for example of a self-supporting moving sidewalk.
In order to achieve the desired rigidity, combinations of T and U sections welded together are typically used that together form an essentially U-shaped channel that is given additional rigidity by transverse struts. This design has proven to be effective even with long unsupported lengths, for example of even 20 m or 30 m.
On the other hand, the use of such solid steel constructions is expensive and labor-intensive, and also demands heavy-duty supports at the entry and exit. This is unfavorable, as it increases the cost of the building in which the escalator or moving sidewalk is to be installed. If, for example, an escalator extends between different floors in a department store, the escalator shaft is not typically located next to pillars. The high support weight means, however, that considerable forces have to be bome, so that possibly the thickness of the concrete ceilings or at least the reinforcement has to be increased.
It is naturally also possible to install supporting columns that extend from bottom to top through the escalator shaft. Such pillars are undesirable, however, for esthetic reasons.
It has furthermore been known for around 15 years that a wire rope can be used as a bearer for an escalator frame. Such a solution was installed, for example, by CNIM, 35 rue de Bassano, Paris, in Paris-Bercy Charenton in the early 1990s. This solution is somewhat unsatisfactory from an esthetic point of view, however, as the exposed steel rope gives a very technical impression, even though it contributes to minimizing the weight of the frame.
A further problem is the high cost for creation of the supporting structure. The frames are typically prefabricated in sections of, for example, 2 m or 3 m in length by welding together the sections at the factory. On site they are then lifted to the desired position with cranes or lifting platforms or similar equipment and welded together there. This solution is extremely time and labor-intensive, requires heavy equipment and is a major contribution to the costs for the construction of the escalator.
The object of the invention is therefore to create an escalator or moving sidewalk that is lighter in weight without losing rigidity so that it can also be used for buildings with a low load-bearing strength while at the same time reducing the manufacturing costs.


A connector holding device includes a body-side connector attached to an apparatus body; a cord-side connector for fitting with the body-side connector, provided on the front end of a cord drawn out opposite to the side fitting with the body-side connector; and a connector holding member for holding the cord-side connector, having an opening formed with its cord side smaller than its side fitting with the body-side connector. The device attaches the connector holding member to the apparatus body in a state where the cord-side connector fits with the body-side connector.

Conventionally, a cord (e.g. power cord) of an electronic appliance is detachable from the body of the appliance for easy handling and exchange. With this type of connector, a detached connector causes power interruption, or an almost detached connector can cause electric leakage due to imperfect contact between connectors.
To solve such a problem, a structure including a mechanism for locking connectors has been disclosed conventionally (refer to patent literature 1, for instance).
FIGS. 8A, 8B, and 8C are external perspective views of a locking mechanism of a conventional connector described in patent literature 1. As shown in FIG. 8A, the locking mechanism includes panel 11 of apparatus body 10, opening 12 provided in panel 11, and shielding plate 13 provided on panel 11. Shielding plate 13, attached to panel 11 rotatably centering on a supporting point (not shown), opens and shields opening 12. Shielding plate 13 is provided with notch 13a at the bottom-end edge thereof. Further, the connector locking mechanism includes connector 14. Connector 14 is attached to the inner part of opening 12 and electrically connected to a circuit (not shown) inside apparatus body 10.
As shown in FIG. 8B, with shielding plate 13, the arc center of a fan-shaped member having a pair of arc outer circumferences is pivotally supported to a fixed shaft (not shown), being vertically rotatable. Hence, vertically rotating shielding plate 13 makes connector 14 open to the outside and be shielded from the outside.
Power cord 21 has plug 22 on the front end thereof for electrically connecting to connector 14. Stage 23 on the back of plug 22 is formed smaller than plug 22.
In the locking mechanism of a conventional connector thus structured, shielding plate 13 attached to panel 11 of the apparatus body is first rotated upward to make connector 14 be in an open state. Next, plug 22 of power cord 21 is inserted through opening 12 to make connector 14 fit with plug 22 to be electrically connected.
After that, as shown in FIG. 8C, shielding plate 13 is rotated downward to make opening 12 of panel 11 shieldable. On this occasion, notch 13a provided at the bottom-end edge of shielding plate 13 fits with stage 23 on the back of plug 22. This structure allows plug 22 to be held in a space between shielding plate 13 and connector 14 to engage plug 22.
However, the following problem is found in the conventional connector locking mechanism described in above patent literature 1.
For instance, the locking mechanism can be released if the apparatus body is placed upside down or inclined, or if the cord is moved. An attempt to adequately work the locking mechanism causes shielding plate 13 to be vertically rotated with difficulty, resulting in attaching and detaching of the cord with difficulty. Further, shielding plate 13 needs to be made of a hard material, which causes damage and breakage due to a load added to stage 23 on the back of plug 22.    [Patent literature 1] Japanese Utility Model Unexamined Publication No. H07-14575