A process to perform a flaring operation on a rotating electrical device (stator) designed with a number of these spaced axially oriented splines around its perimeter. The design of the stator requires that these perimeter splines possess a flared outer end, creating a rounded cavity contour between adjacent splines to effectively retaining the stator winding in place. The method of this invention reduces damage to the stator windings and allows more wire fill during the manufacturing process.

1. Field in the Invention
The present invention relates to stator windings for use in rotating electrical devices and more particularly, to an improved method for forming the stator, particular to a roll forming process to efficiently and effectively form the stator.
2. Discussion of Relevant Art
During the manufacture of rotating electrical devices, lengths of wire, called xe2x80x9cconductorsxe2x80x9d, are wound around the stator structure. This winding process usually causes the windings and internal motor leads to be formed through relatively narrow apertures and into wire slots, which can often cause the insulation on the conductors to be damaged. When a rotating electrical device is used in a high temperature and/or in a corrosive environment, the damage caused on the insulation can cause premature failure of the device.
This invention is particularly suited to a stator having splines formed about an outer or inner periphery of the central stator body. For this design, the windings must be threaded between the splines through a narrow gap between each successive spline during the manufacturing process. That operation can cause damage to the windings and lack or wire fill in the slots.
There is a need for improved stator structure and a method of making same which will reduce the manufacturing costs, help wire slot fill, and reduce the likelihood of damage to the insulation of the conductors, and thus eliminate or minimize the risk of resulting failure and improve stator output.
The present invention has been contemplated to overcome the foregoing deficiencies and to meet the above-described needs. Specifically, the present invention comprises a stator structure for a rotating electrical device with stator windings formed by conductors coated with insulation. During the manufacture of the stator structure, specifically the stator splines, are formed to improve the manufacturing process and allow more fill, which reduces imperfections and damage to the windings and produces more output.
The device and method of this invention is used to perform a flaring operation on a cylindrical automotive alternator component (stator) designed with a number of evenly spaced axially oriented splined around its inner or outer diameter. The design of the stator requires that these perimeter splines possess a flared end to retain the windings, creating a rounded cavity contour between the adjacent splines. The splines would be put into the cylindrical surface of the stator by means of another process, e.g., a wire EDM process, stamping or cold forming, prior to the winding operation.
To form the flared outer or inner portion according to the invention, the preferred embodiment of the invention uses a series of forming rollers that pass lengthwise along each spline to gradually and sequentially flare out the end surface of the spline. Each roller deforms the material slightly, spreading the material in the circumferential direction, and the successive rollers are designed to make an additional incremental deformation to the same surface so that after passing a number of rollers across the spline the flared geometry is achieved.
Preferably, these rollers are contained within a large carriage, designed to carry the rollers at the correct spacing relative to each other and relative to the component being worked on. Each roller is mounted on suitable bearings to allow it to rotate while being driven against the rotor component. The carriage itself moves in a direction parallel to the axis of the component part, mounted in turn through suitable bearings onto a rigid stationary platform, and powered by a suitable linear motive device such as a hydraulic cylinder.
The stator component to be formed is clamped in place by a supporting clamping mandrel, which supports the stator material against the force of deformation, and also serves to align the splines relative to the position of the rollers. This same clamping mandrel may be indexed rotationally to present successive splines to the same forming action, or the rollers may be formed to contact more than one spline at a time. The result is that with a single stroke of the carriage, a fully formed flare would be created on one or more splines. Successive strokes of the carriage are performed after rotationally indexing the component to the next spline or set of splines, until the entire perimeter of the component is fully formed in this fashion.
The method of this invention thus provides an improved stator design and a method manufacturing a stator that provides a substantially improvement in the reliability, manufacturing costs and stator geometry as compared to known systems and methods.

Sequential roll-forming process for a stator


A ventilating device of a window type air conditioner, which includes: a ventilating hole formed in a partition that connects the room portion with the outdoor portion of the air conditioner; a first lever which moves forward and backward in the discharge grill and the room portion; a lever guide portion that prevents the first lever from being deviated when the first lever is moved forward and backward, maintaining the horizontal state of the first lever; a damper on the back end portion of the first lever that opens and closes the ventilating hole with the forward/backward movement of the first lever; and a second lever which is formed on the front end of the first lever and is received in the room portion of the body during the shipment of the product, but is rotated in a straight line with the first lever, by an artificial force, to be exposed to the exterior of a front panel in the front end portion thereof, after installation of the product.

1. Field of the Invention
The present invention relates to a window type air conditioner, and more particularly, to a ventilating device of a window type air conditioner which is capable of supplying outdoor air to the inside of a room. By making the proper selection during air conditioning, the user ventilates the air inside the room with outdoor air.
2. Discussion of Related Art
Generally, an air conditioner is used to heat-exchange hot air in a room into cool air in order to air-condition the room to a predetermined temperature. Air conditioners are divided into three general types based on where they are installed. The first type of air conditioner is installed on the floor of a room; the second type of air conditioner is installed attachably on the wall surface of a room. The third type of air conditioner is installed in a window. The first and second types of air conditioners include an indoor device and an outdoor device which are separated from each other, and the third type of air conditioner integrates the room device and the outdoor device with each other.
First, the construction of a conventional window type air conditioner will be described with reference to FIGS. 1 to 4. The conventional window type air conditioner is comprised of: a body 1 that is attached in a window frame and that has a plurality of air holes 2 on both of its sides and the upper surface thereof. A front panel 5 is attachably/detachably coupled to the front surface of the body 1 and has an intake grill 3 and a discharge grill 4. A separating plate 6 is fixed in the interior of the body 1 and separates the body 1 into a room portion 1a and an outdoor portion 1b; a fan 7 is installed in the room portion 1a of the body 1 and rotates by the driving force of a motor (not shown) generating an intake force. A heat exchanger 8 is installed in the indoor portion 1a of the body 1 and heat-exchanges the hot indoor air which is pulled in through the intake grill 3 according to the rotation of the fan 7, transforming the indoor air into cool air.
Upon installation of the window type air conditioner described above, the front panel 5 is positioned in the room, and the plurality of air holes 2 on the body 1 is positioned outdoors.
When the air-conditioning mode is selected by turning dial 10, located on the control plate on the front panel 5, the air conditioner begins to run. The air conditioner runs at variable rates depending on the selected control signal.
More specifically, the rotating fan 7 generates an intake force that sucks the hot indoor air into the room portion 1a of the body 1 through the intake grill 3. At the same time, because the heat exchanger 8 executes a heat exchange operation, the hot air sucked into the room portion 1a is changed into cool air, while passing through the heat exchanger 8. The cool air is discharged into the room through the front panel 5 and the discharge grill 4 due to the force generated by the rotating fan 7. Thus, the room is air conditioned to a predetermined temperature.
Because the conventional window type air conditioner performs the air conditioning by continually circulating the air in the room, the air becomes impure if the air conditioning runs for a long time period. To solve this problem, the window type air conditioner includes a ventilating device, which selectively supplies outdoor air to the room and thus prevents the indoor air from becoming impure.
FIG. 1 provides a perspective view of a window type air conditioner having a conventional ventilating device, FIG. 2 is a cross-sectional view illustrating the main parts of FIG. 1 and FIG. 3 is a sectional view taken along the line I--I of FIG. 2. FIG. 4 is a perspective view of the conventional ventilating device of FIG. 1. In the first embodiment of the prior art, the ventilating device includes: a ventilating hole 11 in the separating plate 6, that connects the room portion 1a with the outdoor portion 1b. A lever 12, which moves forward and backward in the room portion 1a of the body 1, to expose the front end portion thereof to the outside of the front panel 5 through the discharge grill 4. The lever 12 maintains a horizontal state because a lever guide portion ensures that the lever is not deviated during its own forward/backward movement. A damper 13 on the back end portion of the lever 12 opens and closes the ventilating hole 11 during the forward/backward movement of the lever 12. A pair of grooves 14, which are formed opposite to each other, are located on the front end of the lever 12 and serve as a handle grip.
The lever guide portion is comprised of a vertical hole 15 which is vertically formed on the lever 12, a guide projection 16 which is formed in the bottom surface of the room portion 1a and is inserted into the vertical hole 15, and a screw 17 which is screwed on the guide projection 16 on the upper portion of the lever 12.
Now, the assembling process of such conventional ventilating device as mentioned above will be discussed. While the front panel 5 is not coupled with the front surface of the body 1, the guide projection 16 is inserted into the vertical hole 15, and then the screw 17 is screwed on the guide projection 16 on the upper portion of the lever 12. As a result, the lever 12 is located in the room portion 1a to be movable forwardly/backwardly, without deviation.
Thereafter, if the front panel 5 is coupled with the front surface of the body 1, the front end portion of the lever 12 is exposed to the exterior of the front panel 5 through the discharge grill 4.
The window type air conditioner attaches on a window 9, and if ventilation is desired in an air conditioning operation mode, a user grasps the pair of grooves 14 on the front end portion of the lever 12 and pulls the lever 12 forward. To the contrary, if ventilation is not desired, the user pushes the lever 12 backward.
The damper 13 closes the ventilating of hole 11, such that the room portion 1a and the outdoor portion 1b are not connected. In this case, although the air conditioner is in an air conditioning state, the outdoor air in the outdoor portion 1b that came in through the air holes 2 is blocked from entering the room portion 1a, and no ventilation is archived.
When the user pulls the lever 12 forward, the guide ensures that the lever moves horizontally in a forward direction. Accordingly, since the damper 13 opens the ventilating hole 11 in the separating plate 6, the outdoor air in the outdoor portion 1b is supplied to the room portion 1a. The outside air mixes with the air cooled by the heat exchange 8 and is discharged to the room through the discharge panel 4,
FIG. 5 is a cross-sectional view illustrating the main parts of a window type air conditioner having a ventilating device constructed according to a second embodiment of prior art. FIG. 6 is a perspective view illustrating the lever of the ventilating device of FIG. 5. The ventilating device is well disclosed in Japanese patent publication number 6-129669. This embodiment provides a ventilating hole 21 in the separating plate 6. The ventilating hole 21 connects the room portion 1a with the outdoor portion 1b. A lever 22, which is hinge-installed to be horizontally rotatable, moves in the room portion 1a of the body 1, to expose the lever's front end portion to the outside of the front panel 5. A damper 23 formed on the back end portion of the lever 22 is rotated horizontally to open or close the ventilating hole 21.
An explanation of the assembly process for the conventional ventilating device is avoided because it is similar to that of the first embodiment of the conventional device, as discussed above. Meanwhile, the ventilation procedure during the air conditioning process will be explained.
If ventilation is desired, the front end portion of the lever 22, exposed to the exterior of the front panel 5, is pulled rotating the lever 22 counterclockwise. If ventilation is not desired, the lever 22 is rotated clockwise.
In the state shown by the solid line of FIG. 5, the damper 23 closes the ventilating hole 21, such that the room portion 1a and the outdoor portion 1b are not connected. In this case, although the air conditioner is in an air conditioning state, the outdoor air is not supplied to the room portion 1a, preventing ventilation.
Under the state shown by the dotted line of FIG. 5, if the user pulls the front end portion of the lever 22 counterclockwise because the lever 22 is hinge-installed at the bottom surface of the room portion 1a, the lever 22 rotates counterclockwise opening the ventilation hole 21.
Accordingly, since the ventilating hole 21 is opened, the outdoor air from the outdoor portion 1b mixes with indoor air in the room portion 1a. The mixed air passes through the heat exchanger 8 and cool ventilated air is discharged to the room through the discharge panel 4.
The ventilating devices of the first and second prior art embodiments, since the front end portion of the lever is exposed to the exterior of the front panel 5 when the assembly is complete, is problematic. First, upon package of the product for shipment, an increased package area is required to cover the exposed portion of the lever, thus increasing the cost of the package. Second, the number of products that can be loaded for delivery is reduced due to the increased packaging size, and thus the cost of delivery is increased. Finally, often during packaging and delivery, the packaging is torn off or the broken lever is often generated.
Moreover, the ventilating device of the first prior art embodiment is extremely complicated due to assembly of the lever, and the yield of production is accordingly decreased.

Ventilating device of window type air conditioner


An internal combustion engine having at least two combustion chambers, the internal combustion engine having at least one sensor for detecting a parameter partially characterizing the course of combustion, in particular a parameter correlating with an internal combustion chamber pressure. The sensor is situated in a region of the internal combustion engine between two mutually adjacent combustion chambers.

Pressure sensors, which measure the pressure prevailing in the combustion chamber directly, can be utilized to determine the internal pressure of a combustion chamber of an internal combustion engine. However, since very high temperature prevail inside a combustion chamber of an internal combustion engine, this type of pressure measurement is generally used only on test stands.
Conventionally, sensors are used to measure the pressure in the combustion chamber not directly but indirectly. In European Patent No. EP 0 621 470 A2, for example, a cylinder-pressure sensor is described which can be screwed into a thread provided to accommodate the spark plug assigned to the combustion chamber. German Patent Application No. DE 198 03 470 A1 describes capacitive strain-sensing elements which detect the surface expansion of a component that is directly or indirectly acted upon by the pressure prevailing in a cylindrical combustion chamber.
German Patent Application No. DE 101 08 051 A1 describes disposing force sensors between the head of a cylinder-head bolt and the upper face of the cylinder head of an internal combustion engine in order to infer the internal pressure of a combustion chamber via the linear deformation of the cylinder-head bolt.
Conventional devices have the disadvantage that the precise detection of a parameter correlating with an internal pressure of a combustion chamber is relatively complicated and may require a multitude of sensors, in particular.

Internal combustion engine including a sensor for detecting a parameter partially characterizing a course of combustion and strategically positioned between two adjacent combustion chambers


The present invention pertains to a dye-based inkjet ink set and, more particularly, to a dye-based inkjet ink set suitable for printing on polyamide fabric. The present invention also pertains to a method for printing a polyamide fabric with the dye-based inkjet ink set, and a polyamide fabric so printed.

The present invention pertains to a dye-based inkjet ink set and, more particularly, to a dye-based inkjet ink set suitable for printing on polyamide fabric.
Digital printing methods such as inkjet printing are becoming increasingly important for the printing of textiles and offer a number of potential benefits over conventional printing methods such as screen printing. Digital printing eliminates the set up expense associated with screen preparation and can potentially enable cost effective short run production. Inkjet printing furthermore allows visual effects, like infinite pattern repeat sizes, that cannot be practically achieved with a screen printing process.
One area of textile printing ideally suited to digital printing is the flag and banner market where short runs are common. However, printing of flags and banners presents unique challenges. For example, ink is printed on one side, but must penetrate the fabric so that the image is equally visible on the back (unprinted) side as on the front (printed) side. In addition, while the ink must travel through the fabric, it must not travel laterally causing blurring and bleeding. This seemingly contradictory set of conditions is not easily achieved. Furthermore, the printed products will typically be displayed in sunny areas and the colorants in the inks are preferably resistant to light fade.
U.S. Pat. No. 5,847,740 discloses an inkjet printing process on nylon cloth. Co-pending and commonly owned U.S. application Ser. No. 11/070711 (filed Mar. 2, 2005) discloses flag and banner printing methods and pretreatment solutions therefor. The disclosures of these documents are incorporated by reference herein for all purposes as if fully set forth.
It is an object of this invention to provide an inkjet ink set having good gamut, light-fastness and penetration properties that is advantageous for printing on polyamide fabric.


A logistics assembly is configured to be coupled to a sidewall of a trailer. The logistics assembly includes a logistics strip configured to be coupled to an inside surface the sidewall of the trailer and a splicing plate configured to be coupled to an outside surface the sidewall of the trailer. The splicing plate is spaced-apart from the logistics strip to define a channel therebetween, and the logistics strip includes a plurality of vertically-spaced slots aligned with the channel. The logistics assembly further includes an insert engaged with the logistics strip and the splicing plate. The insert is configured to block access from inside the trailer through at least one slot of the logistics strip in order to prevent debris from entering through the slot and into a channel between the logistics strip and the splicing plate.

The sidewalls of trailers often include logistics strip assemblies in order to enable engagement of restraining equipment and straps to the sidewall of the trailer. In particular, the logistics strips typically include one or more slots configured to receive a logistics clip attached to a logistics strap or cable used to secure cargo within the storage container of the trailer. Debris from within the storage container of the trailer may enter the logistics strip assembly via one of the apertures, or slots, of the assembly. Such debris may accumulate between the logistics strip and a splicing plate of the logistics strip assembly to cause contamination and/or corrosion.

Insert for logistics slot in logistics strip assembly


A syringe-type container for liquid medicine which includes a barrel provided with an easily breakable piercing needle at a distal end of a needle-connecting portion thereof; a gasket inserted and held in the barrel; and a guide means fitted on the barrel from the distal side wherein. The syringe-type container is so constructed that turning of the guide means relative to the barrel breaks off the piercing needle from the needle-connecting portion.

Certain drugs change their nature or deteriorate in quality when stored in the form of a liquid medicine, and accordingly they are stored in a drug container such as vial in the form of a solid, for example a powder medicine or a freeze-dried medicine. Such solid medicines are mixed with a solution injected into the vial with a syringe just before use to reconstitute the liquid medicine in the vial, and the resultant liquid medicine is then withdrawn into a syringe and injected into a patient. For example, a solid medicine prefilled in a vial is reconstructed by withdrawing a solution from an ample or a vial into a syringe (or fitting a needle for dissolution on a prefilled-syringe containing a solution prefilled therein), causing the needle to penetrate into the rubber stopper of the vial and ultimately into the vial, injecting the solution in the syringe into the vial to reconstitute a liquid medicine by mixing the solution with the solid medicine, and then withdrawing the resultant liquid medicine from the vial into the same syringe.
In the conventional method using a syringe, it is required to use a metal needle for reconstituting of a liquid medicine. Thus, there is a fear of injuring a user with the needle. Also, there is the possibility of coring when the needle is caused to penetrate into the rubber stopper at an angle with respect to the top plane of the stopper.

Syringe-type container for liquid medicine


Digital microprinters such as maskless projection lithography systems can be adversely affected by pixel cross talk resulting from coherent interactions between adjacent pixels. Such effects are significantly mitigated by inducing a xcfx80/2 optical phase shift between adjacent pixels. In one implementation, the printing surface is exposed twice, with the phase shift sign-inverted between exposures so that coherent interaction effects cancel out between the two exposures.

The invention relates generally to digital microprinters and more specifically to digital microprinters such as maskless projection lithography systems that use spatial light modulators (SLMs) for optical pattern generation (Refs. 1-6).
Such microprinters can be adversely affected by pixel cross talk resulting from coherent interactions between adjacent pixels. Such interactions could be mitigated by spacing the SLM pixels sufficiently far apart that there is no significant overlap between adjacent pixels"" point spread functions at the image plane. Or alternatively, pixel exposures could be sequenced so that adjacent pixels are never on at the same time. However, these approaches can result in very low optical efficiency because illumination energy that intercepts the SLM between pixels, or on pixels that are in their off state, is wasted. Printing speed is limited by optical efficiency, so it would be desirable to use closely spaced pixels and to allow adjacent pixels to be simultaneously on in order to optimize efficiency.
This invention provides an optical technique for mitigating pixel cross talk resulting from coherent interactions between adjacent pixels in a digital microprinter. No loss in optical efficiency or printing speed is incurred.
The invention is applicable to a printer system that uses a spatial light modulator (SLM) for image generation. The SLM comprises an array of source pixel elements, each of which is digitally controlled to modulate illuminating radiation intercepting the pixel. Either a transmission-type or reflection-type of SLM can be used. A projection system conveys the modulated radiation to a printing surface wherein each source pixel generates a corresponding modulated exposure field that exposes the surface. (In some embodiments the SLM may be imaged directly onto the printing surface. Alternatively, the SLM may be imaged onto an intermediate image plane proximate to a microlens array, wherein each microlens condenses the illumination from a corresponding source pixel onto a focal point on the printing surface.) Due to the projection system""s limited optical resolution, adjacent pixels"" exposure fields may overlap, resulting in pixel cross talk effects due to coherent interaction between the overlapping fields.
The coherent effects are significantly mitigated by configuring the SLM to induce an optical phase shift on alternate pixels, wherein the phase shift induces a phase offset of approximately xcfx80/2 between adjacent pixels"" exposure fields. (Typically, the phase shift would be exactly xcfx80/2 at a specific wavelength within the illumination""s spectral band.) If the exposure fields (without the phase shift) have a uniform phase distribution across the printing surface, this technique can substantially eliminate the coherent interaction between adjacent pixels. If the phase distribution is not uniform, an alternative technique can be employed in which two exposures are made, with the positional relationship between the SLM and printing surface altered between exposures so that the induced phase offset is sign-inverted.
A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.

Pixel cross talk suppression in digital microprinters


In an address multiplexing apparatus for multiplexing address data to be supplied to 64K bit, 256K bit, and 1M bit DRAMs, upon multiplexing of address data, input address data of 20 bits are classified into two groups, i.e., the lower 16 bits and the upper 4 bits. The lower 16-bit group is multiplexed so that the upper 8 bits serve as row address data, and the remaining lower 8 bits serve as column address data. In the upper 4-bit group, adjacent bits are multiplexed. The apparatus can be commonly used for the three memories having different capacities with the simple circuit arrangement, and page mode access can be executed.

The present invention relates to an address multiplexing apparatus for multiplexing address data for accessing a memory and, more particularly, to an address multiplexing apparatus which can be commonly used for a plurality of types of memories.
A dynamic random access memory (to hereinafter be referred to as a DRAM) is a typical known memory to which multiplexed address data is supplied. A conventional address multiplexing apparatus will now be described, with reference to access control of a DRAM.
A signal in which 2n-bit address data for designating a cell to be accessed is multiplexed such that n bits serve as row address data and the remaining n bits serve as column address data is input to a DRAM. For example, in the case of a 256K bit DRAM requiring the input of 18-bit address data in order for a cell to be selected and accessed, 9 bits of the address data are input as row address data, and the other 9 bits are input as column address data. Conventionally, the 2n-bit address data is multiplexed so that the upper n bits serve as row address data and the lower n bits serve as column address data. For this purpose, the conventional address multiplexing apparatus receives nonmultiplexed address data from, for example, a processor, and a signal, supplied from a DRAM access timing generator, for designating whether a row address (RAS) or a column address (CAS) is to be selected. The apparatus multiplexes the received address data in accordance with the signal designating the row or column address, so that the upper n bits serve as the row address data and the lower n bits serve as the column address data, and outputs the multiplexed address data.
In this case, when the DRAM is continuously accessed and if addresses to be accessed have the same upper n bits, the row address need not then be input, the column address only being input. This is known as "page mode access". Using this method, the time necessary for accessing the memory can be shortened.
However, in the case of such a multiplexing method being used, it is then difficult to realize an address multiplexing apparatus which can be commonly used for a plurality of types of memories having different capacities. For example, assume that an address multiplexing apparatus is designed, which can be commonly used for a 256K bit DRAM requiring 18-bit address data, and a 1M bit DRAM requiring 20-bit address data. Then, multiplexed output address data will require 9 bits, in the case of the 256K bit DRAM, and 10 bits, in the case of 1M bit DRAM. For this reason, output lines corresponding to 10 bits must be provided, and multiplexing as shown in FIG. 5 must be performed. A multiplexing apparatus which realizes this multiplexing method receives signals respectively designating 1M row address data (RAS-1M), 256K row address data (RAS-256K), and column address data (CAS), and outputs address data multiplexed in accordance with the received signals. Since the output address has been multiplexed, a 3-to-1 selector must be used to select one bit of the input address data in accordance with each of the nine lower bits of the multiplexed output address. More specifically, when the output address has been multiplexed in the format of FIG. 5, the 3-to-1 selector selects, for example, bit A.sub.0 when the column address of 1M mode or 256K mode, bit A.sub.9 when the row address of 256K mode, and A.sub.10 when the row address of 1M mode in accordance with the least significant bit M.sub.0 of the multiplexed output address.
With the aim of realizing the multiplexing shown in FIG. 5, a circuit has been proposed which comprises ten 3-to-1 selectors 63 arranged between input address line 61 and output address line 62, as is shown in FIG. 6. As is shown in FIG. 7, each selector 63 comprises three AND gates 71, 72, and 73, one OR gate 74, and two inverters 75 and 76, and has a very complicated arrangement.
If this multiplexing apparatus is also to be used for a 64K bit DRAM requiring 16-bit address data, as well as for the 1M bit and 256K bit DRAMs, then the multiplexing shown in FIG. 8 must be performed and a 4-to-1 selector must be used to select one bit of the input address data in accordance with each of the eight lower bits of the multiplexed output address. In this case, the arrangement of each selector is more complex than that shown in FIG. 7. Thus, when a single address multiplexing apparatus is commonly used for a plurality of types of memories, the address multiplexing apparatus becomes increasingly complicated and larger in scale.
As may be understood from the two multiplexing apparatuses described above, any apparatus, that is designed to simply multiplex 2n-bit address data so that the apparatus can be used in addressing memories of different capacities, is inevitably very complex. If two adjacent bits are multiplexed, a 2-to-1 selector may be used, but page mode access cannot be performed.


A condition-monitoring device of the invention, which is provided in an electromagnetic actuator including a stationary core, a moving core, magnet coils; and a permanent magnet, monitors condition of the electromagnetic actuator. The condition-monitoring device includes a current measurement means for measuring a current flowing through the magnet coils; magnetic-flux measurement means for measuring magnetic flux inside the stationary core; a calculation means for generating a calculated waveform by performing a calculation using a current waveform representing a time variation of an output signal from the current measurement means and a magnetic-flux waveform representing a time variation of an output signal from the magnetic-flux measurement means; and a condition determination means, by finding a distinctive point on the calculated waveform, for determining conditions of the electromagnetic actuator based on information on the distinctive point.

As a measurement device that measures switching contact wear, which is one of condition parameters of a circuit breaker, there has been, for example, a device that measures, by detecting using optical sensors the positions of marks attached to the drive shaft connected to the drive coils of an electromagnetic actuator, and checks the amount of deviation of the marks from their original positions due to wear of the contacts (for example, refer to Patent Document 1).
Patent Document 1: GB Patent Application Publication No. 2350724A (lines 15-20 on page 5 and FIG. 4)

Condition-monitoring device and switch-control device provided with the same


The image forming device includes a chassis; a thermal head unit pivotably supported by the chassis for executing printing; a platen roller supported by the chassis opposite the thermal head unit; a pressing member that is pivotably supported by the chassis and configured to press the thermal head unit against the platen roller by pushing against a top portion of the thermal head unit; a protruding part that is provided on the top portion of the thermal head unit and configured to engage the pressing member in a horizontal direction as the pressing member is pivoted to press the thermal head unit against the platen roller; and a positioning member configured to engage the thermal head unit as the thermal head unit is pushed in the horizontal direction due to the engagement of the protruding part with the pressing member in the horizontal direction.

1. Field of the Invention
The present invention relates to an image forming device. More specifically, the present invention relates to an image forming device equipped with a member that presses a thermal head unit.
2. Background Information
Various structures of thermal transfer printers and other image forming devices have been proposed which include a member for pushing a thermal head or print head.
An image forming device is a known example of the thermal transfer printer. FIG. 18 is a perspective view showing the overall structure of a known example of a thermal transfer printer. FIGS. 19 to 21 illustrate the thermal transfer printer shown in FIG. 18 in more detail. This thermal transfer printer will now be described with reference to FIGS. 18 to 21.
As shown in FIGS. 18 to 21, this thermal transfer printer includes a metal chassis 101, an ink ribbon cartridge 102, a take-up reel 103 (see FIGS. 19 and 20), a thermal head unit 104 for executing printing, a platen roller 105 (see FIG. 21) arranged opposite the thermal head unit 104, platen roller bearings 106 configured and arranged to rotatably support the platen roller 105, pressing member 107, a resin drive gear unit 108 for pivoting the pressing member 107 that has a small diameter gear 108a and a large diameter gear 108b, a metal feed roller 109 (see FIG. 19) for feeding printer paper 130, a metal pressing roller 110 (see FIG. 19) arranged to press against the feed roller 109 with a prescribed pressing force, feed roller bearings 111 configured and arranged to rotatably support the feed roller 109, pressing roller bearings 112 (see FIG. 19) configured and arranged to rotatably support the pressing roller 110, bearing support plates 113, a helical coil spring 114 (see FIG. 21), tension coil springs 115, an electric motor 116 (see FIGS. 19 and 20) for driving the feed roller 109 and the take-up reel 103, an electric motor 117 for driving the pressing member 107, a motor bracket 118, a feed roller gear 119 (see FIGS. 19 and 20), a swing gear 120 (see FIGS. 19 and 20), and intermediate gears 121 and 122 (see FIG. 20).
As shown in FIGS. 18 and 19, the motor bracket 118 is mounted to one side panel 101a of the chassis 101. A cartridge insertion hole 101c for inserting the ink ribbon cartridge 102 is formed on the opposite side panel 101b of the chassis 101. Insertion holes 101d for supporting the pressing member 107 are formed on both side panels 101a, 101b of the chassis 101. One end of each tension coil spring 115 is attached to a spring attaching hole 101e provided in the side panels 101a, 101b of the chassis 101.
As shown in FIG. 18, the ink ribbon cartridge 102 has a take-up part 102a and a supply part 102b. A take-up bobbin (not shown) and a supply bobbin 102c (see FIG. 21) are arranged inside the take-up part 102a and the supply part 102b of the ink ribbon cartridge 102, respectively. The ink ribbon 102d is wound onto the take-up bobbin and the supply bobbin 102c. The take-up reel 103 functions to take up the ink ribbon 102d that is wound onto the take-up bobbin and the supply bobbin 102c by engaging with the take-up bobbin. As shown in FIGS. 19 and 20, the gear 103a of the take-up reel 103 is arranged such that it meshes with the take-up bobbin when the swing gear 120 swings. The swing gear 120 is constantly meshed with the feed roller gear 119.
As shown in FIGS. 18, 19, and 21, the thermal head unit 104 has a support shaft 104a, arm parts 104b, and a thermal head 104c. Support holes 104d are formed on the arm parts 104b. As shown in FIGS. 19 and 21, the thermal head unit 104 is mounted within the side panels 101a, 101b of the chassis 101 such that it can pivot about the support shaft 104a. A gap is provided between the support shaft 104a and each support hole 104d for dimensional tolerance. Also, as shown in FIG. 21, the helical coil spring 114 is attached to the support shaft 104a of the thermal head unit 104 on the side of the support shaft 104a close to the side panel 101a of the chassis 101. The helical coil spring 114 functions to urge the thermal head unit 104 in a direction away from the platen roller 105. As shown in FIGS. 18 and 19, bent parts 104e configured to be pressed by the pressing member 107 are provided on the arm parts 104b of the thermal head unit 104. Also, as shown in FIG. 21, the thermal head 104c of the thermal head unit 104 is arranged such that it presses against the platen roller 105 with the printer paper 130 and the ink ribbon 102d in between.
As shown in FIGS. 18 and 19, the pressing member 107 includes a pivot member 107a arranged on the side closer to the side panel 101a of the chassis 101 and having a toothed part 107d, a pivot member 107b arranged on the side closer to the side panel 101b of the chassis 101, and a support rod 107c. Pressing springs 107e configured and arranged to press the bent parts 104e of the thermal head unit 104 are attached to the pivot members 107a and 107b. The pivot members 107a and 107b are attached to the support rod 107c so as not to be relatively rotatable. As shown in FIG. 21, the toothed part 107d of the pivot member 107a on the side near the side panel 101a of the chassis 101 is arranged such that it meshes with the small diameter gear 108a of the drive gear unit 108. The drive gear unit 108 is mounted to the side panel 101a of the chassis 101 and functions to transfer drive force from the electric motor 117 to the toothed part 107d of the pivot member 107a.
As shown in FIGS. 19 and 20, the feed roller 109 is provided at both ends with bearing support sections 109a each having a smaller shaft diameter than the outermost diameter of the feed roller 109, gear mounting sections 109b, and print paper feeding sections 109c. As shown in FIG. 19, the bearing support sections 109a of the feed roller 109 are rotatably supported by the feed roller bearings 111. As shown in FIGS. 19 and 20, the gear mounting section 109b of the feed roller 109 is inserted into the feed roller gear 119 so as to be relatively unrotatable. Protrusions of a prescribed height are formed by form rolling on the surface of the printer paper feeding sections 109c of the feed roller.
As shown in FIG. 19, the pressing roller 110 is provided with bearing support sections 110a having smaller shaft diameters than the outermost diameter of the rest of the pressing roller 110. The bearing support sections 110a of the pressing roller 110 are rotatably supported on the pressing roller bearings 112. The pressing roller bearings 112 are mounted to the bearing support plates 113, which are provided on the inner sides of the side panels 101a, 101b of the chassis 101. Each of the bearing support plates 113 is mounted to the inner sides of the side panels 101a, 101b of the chassis 101 so as to be pivotable about a fulcrum part 113a. Each of the bearing support plates 113 also has a spring attaching part 113b on which the other end of the respective tension coil spring 115, which urges the pressing roller 110 toward the feed roller 109, is attached. The electric motor 116 is mounted to the motor bracket 118 and serves to drive the feed roller 109 and the take-up reel 103. The driving force of the electric motor 116 is transmitted to the feed roller gear 119 and the gear 103a of the take-up reel 103 through the intermediate gears 121 and 122.
The printing operation of this thermal transfer printer will now be explained with reference to FIGS. 20 and 21. When the electric motor 116 rotates, the motor gear 116a mounted to the shaft of the motor 116 rotates in the direction of the arrow A2 as shown in FIG. 20 and drives the feed roller gear 119 in the direction of the arrow B2 shown in FIG. 20 through the intermediate gears 121 and 122. When the feed roller 109 rotates in the direction of the arrow B2 as shown in FIGS. 20 and 21, the printer paper 130 is fed in the paper feeding direction (direction of the arrow C2 shown in FIG. 21). When this occurs, the swing gear 120 that is swingably coupled to the feed roller gear 119 meshes with the gear 103a of the take-up reel 103 and rotates the gear 103a in the direction of the arrow D2 as shown in FIG. 20.
When the gear 103a rotates in the direction of the arrow D2, the take-up bobbin (not shown), which meshes with the take-up reel 103, rotates and thereby causes the ink ribbon 102d (which is wound onto the take-up bobbin and the supply bobbin 102c) to be taken up. While the printer paper 130 and the ink ribbon 102d are being fed, the drive force of the electric motor 117 is transmitted to the pivot members 107a and 107b of the pressing member 107 through the small diameter gear 108a of the drive gear unit 108, thereby causing the pressing springs 107e to press against the bent parts 104e of the thermal head unit 104. As a result, the thermal head 104c of the thermal head unit 104 presses against the platen roller 105 with the printer paper 130 and the ink ribbon 102d sandwiched therebetween. In this manner, printing takes place.
In the thermal transfer printer shown in FIGS. 18 to 21, the support shafts 104a fit into support holes 104d provided in the arm parts 104b to support the thermal head unit 104 in a pivotable manner, with a gap being provided between the support shaft 104a and each support hole 104d for dimensional tolerance. When the thermal head unit 104 is pivoted, the positioning of the thermal head unit 104 with respect to the platen roller 105 tends to become misaligned due to the gap. As a result, the printing accuracy tends to be compromised.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved image forming device that overcomes the problems of the art. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.


A compact, high-sensitivity magnetometer, including: an optical interface to accept a linearly polarized first light; a pump light source to produce a circularly polarized pump light; a vapor cell comprising a sealed vessel containing an alkali-metal gas, a first input port to receive the first light, a second input port to accept the pump light from a direction perpendicular to the first light, and an output port configured to produce a second light; an electromagnetic source configured to apply an electromagnetic field to the vapor cell at a direction perpendicular to the first light and the pump light; a second linear polarizer, having an axis of polarization perpendicular to the first light, the second polarizer configured to receive the second light and to produce a third light; and a photodetector configured to receive the third light, to produce an intensity measurement of the third light.

Field of the Invention
Embodiments of the present invention generally relate to highly sensitive magnetometers, and, in particular, to a system and method for making magnetic measurements by modulated excitation of atoms. More particularly, the invention relates to atomic magnetometers that rely on polarizing alkali metal vapor, and probing the state of magnetization of the polarized metal atoms.
Description of Related Art
Atomic magnetometers are based on detection of Larmor spin precession of optically pumped atoms. A spin-exchange relaxation-free ("SERF") magnetometer achieves very high magnetic field sensitivity by monitoring a high density vapor of alkali metal atoms precessing in a near-zero magnetic field. In a magnetometer and/or a gyroscope based on that operating principle, it is necessary to measure the precession (i.e., rotation) of the atomic spin state due to the magnetic field with very high sensitivity. One of the most sensitive methods for measuring the Larmor spin precession is via the optical rotation of linearly polarized light propagating through the polarized alkali metal vapor. The highest polarization rotation sensitivity is achieved using two orthogonal polarizers, which are configured to extinguish the light, with the magnetometer cell and a polarization modulator between them. Magnetometers that use a polarization modulation technique use various types of polarization modulator subsystems such as a photoelastic modulator ("PEM") or an electro-optic modulator ("EOM"). The use of a separate polarization modulator adds to the size and complexity of the sensor and can introduce noise and drift. Operation of some atomic magnetometers of the related art is described in U.S. Pat. No. 7,145,333, the entire content of which is hereby incorporated by reference in its entirety.
Therefore, a need exists to provide a miniature, highly sensitive atomic magnetometer having a high level of atomic spin coherence. The atomic magnetometers should have relatively low cost and low measurement drift at low frequency compared to the known art.

System and method for atom-modulated, low-drift sensor


The invention relates to a wiping device for wiping surfaces to be cleaned, especially floor surfaces, comprising a plate-type or frame-type wiping element holder (1), preferably in an essentially long, rectangular form, and a wiping element (4) consisting of textile material or the like, which is adapted and fixed to the wiping element holder (1). Said wiping element (4) respectively comprises, on the upper side facing the wiping element holder (1), close to the two opposing sides, and close to the narrow sides in the long, rectangular form, a narrow fixing strip (5), which is applied with its ends to the wiping element (5) [sic]. Said fixing strip extends approximately transversally on the wiping element holder (1) when the wiping element (4) is fixed to the same (1). Position fixing arrangements are provided on the wiping element holder (1), where the fixing strips (5) should extend when the wiping element is fixed (4). The fixing strips (5) especially consist of textile material or the like and are sewn at the ends thereof to the wiping element (4). The position fixing arrangements (7) are especially embodied as edge recesses starting from the ends, in which the fixing strips (5) are placed in the correct position.

Wiping devices of the type in question have been known for decades, and are colloquially referred to as floor wiping elements (DE 29 14 230 A1). Such a wiping device has in the first place a wiping element holder on which a handle socket is mounted, generally via a cardan joint, so that it can swivel in all directions, and in which a more or less long handle can be inserted. The wiping element holder itself is designed as a generally longitudinally extending rectangular plate or as a correspondingly longitudinally extending rectangular wire frame, optionally with an attachment plate (DE 29 14 230 A1; from the known prior art). The term "longitudinally extending rectangular" also includes in this connection shapes that in plan view deviate slightly from an exact rectangular shape, in particular a trapezoidal shape.
In addition to wiping element holders with a fixed holder or with a fixed wire frame, there have also been known for decades (DE 29 14 230 A1) wiping element holders with a plate or a wire frame that can fold approximately in the middle, and provided with corresponding actuation means.
A wiping element consisting of textile or textile-like material and adapted to the wiping element holder, generally referred to as a flat wiping element, is secured to the latter. This fixing can of course be released since the wiping element has to be squeezed out and/or washed from time to time.
For purposes of fixing to the wiping element holder, the wiping element according to the prior art has in each case on the side facing the wiping element holder and in the vicinity of the narrow sides a fixing element in the form of a securing pocket stitched on three sides. In the case of wiping element holders with a fixed plate or wire frame the insert pockets consist of elastically stretchable material so that they can be sufficiently stretched when pulled over the relevant end of the wiping element holder. In some cases one of the insert pockets is also slit over a more or less long section so as to facilitate the attachment of the wiping element to the wiping element holder.
The wiping element can be attached more easily to the wiping element holder in the case of wiping element holders having a foldable plate or wire frame ((DE 29 14 230 A1). In the folded, i.e. shortened state, the wiping element holder fits between the two insert pockets. By pressing on the folded wiping element holder the latter is brought into the inclined position, whereupon the ends slide into the insert pockets. The wiping element holder is now locked in the extended position and the wiping device can then be used as intended. With such quick-change devices the insert pockets are as a general rule not made of an elastically stretchable material. Often the insert pockets are made of the same or a similar material as the basic fabric of the wiping element itself.
The flat wiping elements widely used in practice with insert pockets stitched on three sides are complicated to manufacture and require expensive production equipment. A common complaint in practice is that the insert pockets become full of water when the wiping elements are rinsed out and the wiping element therefore cannot be adequately dried. Finally, the insert pockets are not part of the cleaning-active mass of the wiping element, although they account for between 7% and 12% of the total weight of the wiping element. Accordingly, 7% to 12% of the material costs of a commercially available flat wiping element with insert pockets are wasted as regards the cleaning function. The same also applies to the costs incurred in washing the wiping elements.
In general it has to be remembered that such wiping elements are widely employed for multifarious purposes in professional use, where business operating margins are low and thus any cost savings are welcomed.
Attempts have already been made to obviate the aforedescribed known disadvantages of wiping elements with insert pockets sewn at the ends, by providing the lower side of the wiping element holder and the upper side of the wiping element with Velcro-type locking elements (DE 22 29 824 AI). These wiping devices have not been widely adopted in practice since, quite apart from the fact that they are complicated and costly to produce, above all the removal of the wiping element necessitates a procedure that can only be performed manually, namely the detachment of the wiping element from the wiping element holder. In contrast to this, particularly when using quick-change holders with a foldable plate or foldable wire frame, in the case of wiping elements provided with insert pockets at the end the dirty wiping element can be removed without the wiping element actually having to be handled.

Wiping device for wiping surfaces to be cleaned


Methods, systems, and devices are described for reducing switches (e.g., ping-pongs) of a wireless communications device between two or more wireless networks. For example, a method includes determining a context of data use of a first wireless network to which a wireless communications device is connected. The method includes determining a time delay associated with performing a switch from the first wireless network to a second wireless network when at least one performance indicator of the first wireless network is below a threshold performance level needed to support the context of data use. The method further includes performing the switch from the first wireless network to the second wireless network in response to the time delay expiring while the at least one performance indicator remains below the threshold performance level.

The following relates generally to wireless communication, and more specifically to switching between two wireless networks. Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, bandwidth, and power). Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems used commonly for communication in Cellular networks, Wi-Fi networks, and the like.
Generally, a wireless multiple-access communications system may include a number of devices (or nodes or stations). A device, such as a wireless communications device, typically favors staying connected to an established wireless network connection (e.g., a Wi-Fi network) until the signal strength weakens or under-performs. When the signal strength of the wireless network connection weakens beyond a threshold, the wireless communications device may switch to another available connection (e.g., a Long Term Evolution (LTE) network) that has signal strength above a threshold. In some cases, the device may connect to the second wireless connection for a period of time before the device reconnects to the first wireless connection. This period of time may be short such that the switch is either not detected by a user and/or does not affect the user experience provided by the device. This type of short handover is referred to as a ping-pong herein. Thus, in some cases, a device may perform unnecessary ping-pongs, which may result in greater battery drain and more mobile data use.

Reducing switching between networks to conserve power and reduce costs


Disclosed herein is a solenoid valve having a valve seat assembly manufactured as a single body such that the valve seat assembly is simply fitted in a valve housing. The valve seat assembly comprises a valve seat, a filter, and a sealing plate. The valve seat assembly is disposed at one end of a housing. The valve seat comprises a first orifice formed such that the first orifice is opened and closed as a plunger is moved forward and backward, and a second orifice formed such that the second orifice is arranged in parallel with the first orifice. The sealing plate is provided at the center thereof with a through-hole, which communicates with the first orifice of the valve seat. The sealing plate is disposed in the valve seat such that the sealing plate is not separated from the valve seat by means of the filter. The sealing plate is moved toward the first orifice by the pressure of a fluid close the second orifice. In this way, the sealing plate serves as a check valve.

1. Field of the Invention
The present invention relates to a solenoid valve, and, more particularly, to a normal open type solenoid valve applicable to an electronically controllable brake system for vehicles.
2. Description of the Related Art
FIG. 1 is a longitudinal sectional view showing the structure of a conventional normal open type solenoid valve 10, which is applied to an electronically controllable brake system for vehicles. As is shown in FIG. 1, the conventional normal open type solenoid valve 10 is operated to constantly open a flow channel when a vehicle is normally braked. When a driver steps on a brake pedal 11a, oil supplied from a master cylinder 11 is delivered to a wheel 12 of the vehicle via a filter 1, an orifice 2a formed at a valve seat 2, and a hollow part 3a and a communication hole 3b formed at a housing 3, by which the vehicle is braked.
When the vehicle is suddenly braked or braked on a slippery road, on the other hand, an electronic control system is operated such that electric current is supplied to a solenoid coil 4. When electric current is supplied to the solenoid coil 4, a magnetic force is generated between an armature 5 and the housing 3 by means of a magnetic field created at the solenoid coil 4 with the result that the armature 5 moves toward the housing 3. Consequently, a plunger 6 moves toward the valve seat 2 along with the armature 5, by which the orifice 2a is closed.
When electric current is not supplied to the solenoid coil 4, the plunger 6 and the armature 5 move back to their original positions by means of a resilient force of a restoring spring 7 such that the orifice 2a is opened. The above-described operations are repeatedly carried out to prevent slippage of the vehicle.
When the driver lifts his/her foot from the brake pedal 11a, the oil is returned from the wheel 12 to the master cylinder 11 via the communication hole 3b, the orifice 2a, and the filter 1, since the oil pressure at the wheel side is higher than that at the master cylinder side. As a result, the oil pressure at the wheel side is released, and thus the brake is released.
The return of the oil must be accomplished as soon as possible after the brake is released such that the wheel 12 is smoothly rotated. In the conventional solenoid valve 10, however, the diameter of the orifice 2a is small. As a result, the return of the oil via the orifice 2a is slow, and thus the oil pressure at the wheel side is not quickly released.
Especially when the orifice 2a is intermittently opened and closed as the electronic control system is operated to prevent slippage of the vehicle, the orifice 2a may be kept closed after the brake is released. For this reason, the conventional solenoid valve 10 further comprises an additional oil return channel and a check valve 8 in addition to the return of oil via the orifice 2a. The check valve 8 has a lip seal 8a, by which the oil is delivered from the wheel side to the master cylinder side. However, the lip seal 8a has a low durability, and the lip seal 8a may be easily deformed by abrupt fluctuation in pressure. Consequently, reliability of the conventional solenoid valve 10 with the above-stated construction is very low.


An earth and sand wear resisting hydraulic machine disposed in pressurized water and having movable guide vanes, has a wear resisting material against earth and sand applied by spraying or welding to the front end of a vane body of each guide vane, to the surface of a vane body portion located below the center of a water flowing portion of the vane body and to upper and lower end faces of the vane body. Consequently, the guide vanes and end faces are protected against wear caused by earth and sand.

1. Field of the Invention
The present invention relates to a hydraulic machine such as a water turbine or a pump turbine. In particular, the invention is concerned with a hydraulic machine applicable also to water containing earth and sand.
2. Description of the Related Art
In hydraulic power generation, water energy created by utilizing the difference between upper and lower water levels is converted into rotational energy by means of a water turbine, and the rotational energy is then converted into electric energy by means of a generator. Recent proportions of atomic power generation and thermal power generation are not less than 80%. However, these power generation methods are inferior from the standpoint of a quick response characteristic. It is hydraulic power generation that is best used to achieve a quick response characteristic.
In pumping-up power generation, which is a hydraulic power generation, water at a lower point or elevation is pumped up into an upper pond through a pump by means of an electric motor utilizing night dump power to store energy, and the water thus pumped up during the night is utilized during the daytime to provide a required amount of electric power. Such a type of a hydraulic machine will hereinafter be referred to as a "pump turbine". Since natural water is utilized, the problem of earth and sand mixed in water energy, or pressurized water, is incidental to hydraulic power generation. Earth and sand mixed in pressurized water strike strongly against the water flowing portion of a water turbine and cause wear of components of the water turbine, which wear may result in damage and eventually inoperativeness of the water turbine. Therefore, a keen desire exists for the development of water turbine components which can resist wear even in collision with earth and sand and also for the attainment of promptness in the replacement of components.
The material of guide vanes so far adopted generally in water turbines and pump turbines corresponds to JIS (Japanese Industrial Standard) SC450 Carbon Steel Castings or JIS-SCS1 Stainless Steel Castings. This material is subject to wear when it collides with earth and sand. As a result of the wear or damage caused by earth and sand, it is periodically required to disassemble the whole of a generator and replace the guide vanes with new ones or repair the old ones, by welding, portions which have been damaged by earth and sand.
However, in repair by welding, the guide vane shafts are bent by the heat of welding and hence it is necessary to transport the guide vanes from the power plant to a machine shop and subject them to machining again. Thus, also in the replacement of guide vanes with new ones or in the repair by welding, a large amount of cost and a long period of time have so far been needed.
Moreover, it has heretofore been necessary for a guide vane operating mechanism in a water turbine or a pump turbine to use a thrust bearing ring for bearing the weight of each guide vane and also for bearing an upward water pressure acting on the guide vane. More particularly, each guide vane is disposed movably between stationary upper and lower covers and it is necessary to provide clearances between the guide vane and those covers. For ensuring those clearances there has been used a strong thrust bearing ring. When passing through the said guide vane clearances, pressurized water increases its flow velocity and strikes violently against upper and lower end faces of the vane portion of the guide vane and also against upper and lower facing plates attached respectively to the upper and lower covers, causing wear which is attributable to earth and sand contained in the pressurized water.
Further, the pressure water leaks from the guide vane clearances and causes deterioration in operation efficiency of the water turbine. In the pump turbine, guide vanes are fully closed during operation of the pump and the water level in a runner chamber is depressed by compressed air. But pressure water from the casing side leaks through the guide vane clearances and strikes against the runner which is rotating in air, thus resulting in that the electric motor for rotating the runner is required to be provided with a large input.
Additionally, the upper and lower casings are apt to cause wear and damage in the guide vane clearances due to collision with earth and sand and when they are to be replaced with new ones, it is necessary to disassemble the whole of both the generator and the water turbine. Accordingly, a very long period is needed for such entire disassembly, replacement of the upper and lower facing plates and the subsequent entire assembly.
Thus, according to the prior art, the components which come into contact with pressurized water containing earth and sand are difficult to be resistant to the pressurized water, and the whole of the generator must be disassembled for the repair of guide vanes and for the replacement of facing plates. During this disassembly, the supply of electric power is interrupted and thus there has been a problem in power transmission system and electric power management.


A method for broadcast assistance in a direct communication system and an apparatus using the same are disclosed. The proposed method includes the following steps. A coordinator receives a broadcast assistance request message from a plurality of broadcast devices. The coordinator transmits a broadcast assistance confirmation signal to the broadcast devices and broadcasts a resource indication signal including a resource allocation. The broadcast devices respectively broadcasts an information message to at least one listening device according to the resource allocation acquired from listening to the resource indication signal, and the at least one listening device listens to one of the information messages having a category of interest according to the resource allocation acquired from listening to the resource indication signal.

1. Technical Field
The disclosure relates to a method and an apparatus for broadcast assistance in a direct communication system.
2. Related Art
Advertising is an attractive revenue growing service for service providers. For example, Google Inc. earns significant revenues through its advertisement services. In a cellular network, advertisements may be implemented through a broadcast function in a communication system with broadcast channels and resource indications. A base station (BS) broadcasts the resource area map of the advertisement message and broadcasts the advertisement message at the allocated area. A mobile station (MS) listens to the map and prepares to listen to the advertisement message in the allocated resource. For example, in Long Term Evolution (LTE), the map might be the region for the Physical Control Channel (PDCCH), and in the IEEE 802.16e/802.16m standards, the map might be the region for the MAP/A-MAP/EMBS-MAP. The BS then broadcasts the advertisement message on the allocated area.
An advertisement scheme can also be implemented in a direct communication system, and a general procedure for advertising in a direction communication system for one to one communication may be as follows. A device contents the resource for transmission and an access point acknowledges the transmission. The device then transmits the data. In a broadcasting scenario, the procedure can be modified to suit the situation at hand.
An approach to realize broadcasting in the direct communication system is for the broadcast device to wait for a time window. If there is no device transmitting signals, the device broadcasts the message. This approach puts the broadcast function at a low priority, even though this approach is adopted for the IEEE 802.11 standard. However, performance cannot be guaranteed when there is a plurality of direct communication devices contenting for the available resource. In some cases, such as in the broadcast transmission for streaming or video applications, equal priority may be necessary.

Method and apparatus for broadcast assistance in direct communication system

Industrial Technology Research Institute


The invention provides a structured aqueous surfactant system comprising: a) at least 0.1 wt % nonionic surfactant which is a polyoxyethylene nonionic surfactant having a hydrophilic head group with at least four oxyethylene units; b) from 0.5 to 5 wt % dispersed modified cellulose biopolymer, wherein the modification consists of the cellulose having its C6 primary alcohols oxidized to carboxyl moieties (acid/COOH—) on 10 to 70% of the glucose units and substantially all the remainder of the C6 positions occupied by unmodified primary alcohols; c) from 0 to 10 wt % non-surfactant electrolyte, and d) water.

Cellulose is a plentiful, and consequently inexpensive, biopolymer. However, in its unmodified form it is completely insoluble and cannot be dispersed into an aqueous liquid composition to achieve a stable, thickened, product.
Partially and selectively oxidising cellulose at the C6 position creates cellouronates or cellouronic acids which are more water dispersible than cellulose but still relatively insoluble.
WO 2010/076292 describes how this type of oxidised cellulose may be used as an alternative structurant for aqueous detergent compositions. This enables the formulator to replace surfactant required for structuring with relatively low concentrations of low cost, partially oxidised, dispersed modified cellulose. These reduced surfactant compositions nonetheless maintain a thick gel-like consistency which allows suspension of solids or gases, such as bubbles, capsules or beads. According to WO2010/076292, in order to provide gelled material it is essential to use anionic or zwitterionic surfactants. The use of a nonionic surfactant (sorbitan trioleate) does not result in a gel.
Surprisingly, we have now found that certain nonionic surfactants are capable of gelling with the oxidised cellulose described in WO2010/076292, even in the absence of any anionic or zwitterionic surfactant.


A system for detecting leaks in a unit. The novel system includes a first mechanism for injecting a first gas into an interior or an exterior of the unit, a second mechanism for sampling gas from an exterior or an interior of the unit to determine if the first gas has leaked out of or into the unit, respectively, and a third mechanism for controlling a differential pressure between the interior and exterior of the unit during sampling. In an illustrative embodiment, the differential pressure is controlled by injecting a second gas into the exterior or interior of the unit to replace the sampled gas, and using pressure regulators to control the pressures of the first and second gases such that the differential pressure remains constant during sampling.

1. Field of the Invention
The present invention relates to systems and methods for detecting gaseous leaks. More specifically, the present invention relates to systems and methods for detecting gas leaks using a mass spectrometer.
2. Description of the Related Art
Some missile systems fully enclose the projectile in a hermetically sealed storage tube in order to physically protect the missile and limit permeation of water into the container. In some systems, the storage tube also serves as a launch tube for the missile. If water should migrate into the missile, it could seriously damage the system (for instance, through corrosion, condensation on the electronics or optics, etc.). During the manufacturing process, the storage/launch tube is therefore hermetically sealed and must be leak checked to ensure that it is sealed to the level required by the system.
The most common method of leak detection involves injecting a tracer gas such as helium around the unit under test and using a mass spectrometer to detect if any of the tracer gas has leaked into the unit. This type of leak detection is very accurate, sensitive, and can quantitatively measure the leak rate of the unit. A mass spectrometer, however, typically requires creating a vacuum in the unit.
Certain missile storage/launch tubes cannot be subject to the 1 atm differential pressure encountered with vacuum leak detection equipment. This is because the storage/launch tube includes end caps that are designed to burst when exposed to pressure or are weakly attached to the tube body (so that the missile can exit the tube during launch). Creating a vacuum inside the tube (or in a test chamber containing the tube) in order to perform a mass spectrometer leak detection test would cause the end caps to burst. This limitation on the differential pressure that can be applied to the tube limits the kinds of leak detection that can be used.
Currently, missile storage/launch tubes are typically leak checked using a pressure decay method. This method involves increasing the pressure inside the tube by a very small amount (typically, about 5 psi) and then measuring the pressure after a certain amount of time has passed (typically, about 45 minutes). If the pressure has decayed by more than a specified amount, then the tube is considered to have an unacceptably high leak rate.
The pressure decay test, however, is relatively insensitive, inaccurate, and slow when compared to mass spectrometer leak detection. Since the test depends on the measured change in pressure, it is very sensitive to temperature changes. Even a fraction of a degree of change in the ambient temperature can cause a false indication of a leak, or worse, mask a real leak. In order to help control the temperature, the missile storage/launch tube is typically placed in a test chamber and allowed to sit for 2 hours in order to come to thermal equilibrium. The pressure decay test is then applied, which takes another 45 minutes. The entire procedure therefore takes about 2 hours and 45 minutes, an excessively long amount of time that can be very expensive (due to labor and equipment costs). The pressure decay test is also very imprecise, since the pressure change being measured is a very small amount. The tube cannot be pumped to higher pressure levels to increase precision because the tubes cannot be subject to larger amounts of pressure, as discussed above.
Hence, a need exists in the art for an improved system or method for detecting leaks in systems that are sensitive to differential pressure that is more accurate and less time consuming than prior approaches.

Leak detection system with controlled differential pressure


A semiconductor memory device includes a memory cell array, a mode register set and a test circuit. The memory cell array includes a plurality of wordlines, a plurality of bitlines, and a plurality of spin-transfer torque magneto-resistive random access memory (STT-MRAM) cells, and each STT-MRAM cell disposed in a cross area of each wordline and bitline, and the STT-MRAM cell includes a magnetic tunnel junction (MTJ) element and a cell transistor. A gate of the cell transistor is coupled to a wordline, a first electrode of the cell transistor is coupled to a bitline via the MTJ element, and a second electrode of the cell transistor is coupled to a source line. The mode register set is configured to set a test mode, and the test circuit is configured to perform a test operation by using the mode register set.

Example embodiments relate generally to semiconductor devices, and more particularly to a semiconductor memory device having resistive memory cells and a method of testing a semiconductor memory device.
Semiconductor products require smaller size and higher capacity for processing a large amount of data, and thus it is required to increase an operational speed and an integration degree of memory components included in the semiconductor products. To meet such requirements, various resistive memories have been proposed. For example, magneto-resistive random access memory (MRAM) realizes memory function using change of resistance depending on change of polarity of magnetic materials.
Recently, various methods are being developed for optimizing a semiconductor memory device including the MRAM cells for mobile devices requiring higher speed and low power consumption. Particularly test methods are required to detect fails and enhance performance of the semiconductor memory device including resistive memory cells such as the MRAM cells.

Semiconductor memory device having resistive memory cells and method of testing the same

Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do


A defroster nozzle is provided inside an instrument panel below a front glass plate, and its length in the direction of vehicle width is gradually increased from a suck-in opening to a blow-out opening. The suck-in opening is connected to an air conditioning unit, and has a bent portion at the middle thereof. The inside of the defroster nozzle is divided by partition walls into a central chamber and side chambers. The length of the central chamber as viewed in the direction of vehicle width is gradually increased from the suck-in opening to the blow-out opening, and the opening areas of the suck-in opening and the blow-out opening of the central chamber are equal to each other. The central portion of the side wall of each of the side chambers has a bent portion. The length of each of the side chambers as viewed in the direction of vehicle width is increased gradually from the bent portion to the blow-out opening, and at each of the bent portion the cross-sectional area of the side chamber is smaller than the opening area on the side of the suck-in opening. At each of the side chambers, the opening area on the side of the blow-out opening is smaller than the opening area on the side of the suck-in opening.

1. Field of the Invention
This invention relates to a defroster nozzle used for a defroster in an automobile.
2. Description of the Related Art
In general, in order to make the front glass plate (or windshield) of an automobile clear, a defroster is employed. In general, the defroster comprises a defroster nozzle, and an air control unit. The defroster nozzle is provided inside the instrument panel of the vehicle chamber, and has a blow-out opening and a suck-in opening. The blow-out opening is opened in the surface of the instrument panel, and the suck-in opening is connected to the air control unit. The air introduced from the air control unit through the suck-in opening is applied to the inner surface of the front glass plate, to dry the front glass plate to make the front glass plate clear.
A defroster of this type should meets the following conditions (performances):
(1) In order to obtain a minimum visibility quickly which is required for safety driving, the performance of quickly make the front glass plate clear uniformly and quickly (so-called "clearing performance") should be improved.
(2) The defroster should be miniaturized, and be decreased in manufacturing cost. In addition, the space required for installation of the defroster should be decreased, so that the degree of freedom with respect to the design of the interior of the instrument panel should be increased.
(3) The ventilation resistance in the defroster nozzle should be decreased, so that the energy loss should be reduced, thereby to minimize the power consumption.
(4) The noise attributing to the ventilation through the defroster nozzle (so-called "ventilation nozzle") should be minimized.


The invention provides for the use of coating compositions based on one or more mineral binders, one or more polymers, one or more fillers, and, if desired, one or more additives for producing roof coatings, the coating compositions comprising at least 50% by weight of polymers, based on the dry weight of the polymers and of the mineral binders.

Roof coatings constitute an upper finish on roofs. Roof coatings protect the roofs and hence also the entire constructions from effects of weathering, more particularly from rain, dew, mist, snow or extreme temperatures. Roof coatings, therefore, are not walls and also not the roof structure, i.e., not the framework of roofs, but instead are an outer skin which is applied to the framework of roofs. Roof coatings are therefore applied on the outer surface of roofs, i.e., on the side of roofs that faces the environment, and not on the inside, i.e., the side facing the interior of buildings. Roof coatings, then, are an outer layer, and preferably the outermost layer, of a roof.
For roof coatings, as alternatives to roofing shingles or concrete, a range of alternatives have been proposed, such as, for example, roof coatings on a bituminous basis, such as roofing felt, or on a polymeric basis, such as EPDM (polymers based on ethylene, propylene, and diene monomers), epoxy (self-crosslinking polymers containing epoxy groups) or PU (polyurethane systems). These systems may be applied in the form of sheets, panels or in liquid form. Also commonplace are TPO films (thermoplastic polyolefin films) or poly-acrylates in liquid form. Existing liquid systems, especially aqueous systems, usually require long drying times upon their application, until the desired roof coatings are obtained. This disadvantage comes to bear particularly under cool or damp conditions. Moreover, during the drying process, there is always the risk of mechanical damage to the coating. In the case of sheets or panels, there is a risk of mechanical damage in the course of transportation to the construction site, or during application on the construction site. Furthermore, the coating of a roof necessitates a large number of panels or sheeting webs, which must be bonded adhesively in order to produce an assembly. These bonding sites, however, are a source of damage as a consequence of deficient bonding or aging, and this may lead to leaks and, ultimately, to failure of the roof coating. Lastly, at application thicknesses in the region of 3 mm, the common aqueous systems exhibit little sag resistance, and this necessitates the use of reinforcing fabric or cladding.


The invention aims at improving the scalability of a storage system using a switch with a small number of ports.

1. Field of the Invention
The invention relates to a storage system in which channel adapters, connected to one or more host systems (host computers) each, and disk adapters, connected to disk drives, are connected via some switches. More specifically, the invention relates to technology on switching paths between host systems (host computers) and disk adapters.
2. Description of Related Art
In a conventional storage system, in which channel adapters, which control connection to one or more host systems (host computers) each, and disk adapters, which control connection to disk drives, are connected via a switch, a configuration is adopted where the storage system is provided with cache memory made from semiconductor memory, which enables faster data access than a disk drive does, and temporarily stores data sent from the host computers in that cache memory, so that high-speed data input/output operation to/from the host computer can be realized. This type of storage system is configured to switch a plurality of paths between channel adapters and disk adapters using some switches (see JP Patent Laid-open Publication No. 2005-258918).

Storage system and method for controlling storage system

Abstract: A storage system includes a plurality of host connection control units 10 connected to host computers; a plurality of drive control units 12 connected to disk drives 13; and a plurality of 4 by 4 switching units 11 located between each of the host connection control units 10 and each of the drive control units 12, and switching a plurality of paths connecting each host connection control unit 10 and each drive control unit 12, wherein the plurality of 4 by 4 switching units 11 is arranged in multiple stages in the direction of information transmission and the 4 by 4 switching units 11 in each stage are connected so that only two paths are defined from a given host connection control unit 10 from among the host connection control units 10, to every drive control unit 12, and the two paths have no parts in common.


A hand held shower head configured to deliver a continuous dose of water dispersed treatment from a water disintegratable treatment source, the shower head including: a hollow body having water inlet opening and water outlet, the water outlet defined by a perforated plate, and a mesh formation disposed within the hollow body between the water inlet opening and the perforated plate, wherein the water inlet opening, hollow body and perforated plate are configured to create in use a pressurised turbulent water flow within the hollow body prior to exiting through the perforated plate, whereby a water disintegratable tablet treatment source introduced into the hollow body prior to use, is then agitated by the turbulent water flow against the mesh in an abrading manner and thereby dispersed into the water flow exiting the perforated plate. A water disintegratable tablet comprising emulsifier, thickening agent, surfactants, oil and rheology modifier is also disclosed.

Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.
The majority of hair treatment processes to date have been based on a discontinuous process of first wetting the hair, separately applying a cleanser or treatment product to the wet or dampened hair, rinsing, and then applying a further treatment as required.
While there are systems available that offer means of applying some form of water conveyed conditioner or cleanser product during the hair wetting process, these have limitations. For example products that automatically deliver liquid cleansers into fixed bathroom shower heads do not provide any dosage control and cannot be directed in a controlled manner to different regions of the hair and scalp.
Similarly, the professional systems that propose use of solid tablets of cleanser or water conditioner in a hand held shower head, have one or more problems including: difficulty achieving a controlled rate of delivery of the cleanser; blocking the holes or perforations in the outlet plate; or needing to use and subsequently remove special containers that deliberately inhibit normal water flow conditions to reduce the rate of dissolution of the tablet. In many cases users of the latter system choose to simply dissolve the tablets in water in the basin and then soak the client's hair in the resulting solution.
It is an object of the present invention to overcome or ameliorate the above discussed disadvantages of the prior art, or at least offer a useful alternative.

Hair treatment system, treatments and apparatus


A surface acoustic wave device includes a piezoelectric substrate, an IDT electrode provided on the piezoelectric substrate, a first dielectric layer, and a second dielectric layer. The first dielectric layer is provided on the piezoelectric substrate and made of silicon oxide. The second dielectric layer is provided on the first dielectric layer and has an acoustic velocity greater than that of the first dielectric layer. A third dielectric layer is provided between the first dielectric layer and the piezoelectric substrate, and arranged to cover a surface of the piezoelectric substrate and an upper surface and side surfaces of the IDT electrode.

1. Field of the Invention
The present invention relates to a surface acoustic wave device used for a resonator, a band pass filter, or other suitable devices.
2. Description of the Related Art
Heretofore, a surface acoustic wave device that utilizes a surface acoustic wave has been widely used as, for example, a resonator or a filter device. For example, in Japanese Unexamined Patent Application Publication No. 2001-44787, as one example of such a surface acoustic wave device, a surface acoustic wave device is disclosed which includes a SiO2 film formed on a piezoelectric substrate so as to cover an IDT electrode and a SiN film formed on the SiO2 film.
As a result of the SiO2 film being formed so as to cover the IDT electrode, the surface acoustic wave device disclosed in Japanese Unexamined Patent Application Publication No. 2001-44787 has excellent frequency temperature characteristics. In addition, in the surface acoustic wave device disclosed in Japanese Unexamined Patent Application Publication No. 2001-44787, when the thickness of the SiN film formed on the SiO2 film is adjusted, the frequency characteristics of the surface acoustic wave device can be adjusted. Thus, the frequency accuracy can be improved.
However, in the surface acoustic wave device disclosed in Japanese Unexamined Patent Application Publication No. 2001-44787, for example, spurious response may be disadvantageously generated between a resonant frequency and an anti-resonant frequency or in a passband due to an unnecessary wave.


A new and distinct variety of nectarine tree (Prunus persica var. nucipersica). The following features of the tree and its fruit are characterized with the tree budded on ‘Nemaguard’ Rootstock (non-patented), grown on Handford sandy loam soil with Storie Index rating 95, in USDA Hardiness Zone 9, near Modesto, Calif., with standard commercial fruit growing practices, such as pruning, thinning, spraying, irrigation and fertilization. Its novelty consist of the following combination of desirable features:                1. Tree with a vigorous, upright growth habit.        2. Regular and productive bearer of large size fruit.        3. Fruit with an attractive red skin color.        4. Fruit having very good flavor and eating quality with a good balance between acid and sugar.        5. Clingstone fruit with firm, white flesh.

Field of the Invention
In the field of plant genetics, we conduct an extensive and continuing plant-breeding program including the organization and asexual reproduction of orchard trees, and of which plums, peaches, nectarines, apricots, cherries, almonds and interspecifics are exemplary. It was against this background of our activities that the present variety of nectarine tree was originated and asexually reproduced by us in our experimental orchard located near Modesto, Stanislaus County, Calif.
Prior Varieties
Among the existing varieties of nectarine trees, which are known to us, and mentioned herein, 'Honey Haven' Nectarine (U.S. Plant Pat. No. 12,393) and 'Polar Magic' Nectarine (U.S. Plant patent application Ser. No. 14,756,155).


Wireless communication devices and systems are disclosed which provides for simple yet effective communications between co-workers in areas of high ambient noise. Devices are provided which are operable to use vibration to provide an alert to a wearer of the device, the device including a transmitter/receiver unit, a transmit button operably connected to the transmitter/receiver unit and at least one vibration device operably connected to the transmitter/receiver unit. The device may be positioned inside or on a hard hat or other headgear of a worker.

Noisy work environments do not always lend themselves to easy communication between co-workers. For example, logging and tree service workers are constantly working amid the noise of power saws, heavy equipment, etc. Exposure to loud noise over time also tends to reduce the hearing ability of such workers. Protective devices such as earplugs also serve to reduce the ability of workers in such environments to hear warnings and communications from co-workers. Such environments pose immediate dangers to workers, who must often rely on their fellow workers to warn them of danger. Effective and reliable communication among co-workers in such environments is essential.


A control system for an optical element such as an optical amplifier in an optical transmission system determines the transmitted optical signal power in each of a plurality of different optical wavelength bands, determines which of the powers is closest to a threshold, and controls an output power of the element, or controls a parameter which affects the threshold, on the basis of the power closest to the threshold. Since there is no longer any need to allow a margin for possible gain variations between different wavelengths, power output can be controlled with reduced upper or lower margins, and thus error rates reduced, or transmission distances increased.

The distance between optical terminals of optical fibre transmission systems is limited by various factors, including the optical power of the optical signal being transmitted. If the power is too low, the signal will be difficult to distinguish from noise. If the power is too great, distortion of the signal will occur. One type of distortion which can occur in optical fibre is self-phase modulation. The onset of this type of non-linear degradation can be quite sharp, in that only one or two dB of increase in power level can push a signal from optimal performance to a failed state.
Thus, for a given target acceptable bit error rate (BER), or acceptable risk of any errors, there will be an upper limit to the optical power of the optical signal when it is launched into an optical fibre by a transmitter. Correspondingly, there will be a lower power limit or threshold for the optical signal at the receiver, following inevitable attenuation in the optical fibre. Output power levels generally need to be held as high as possible so that the power level after attenuation by the optical link does not fall below the noise threshold, and become excessively degraded by optical noise.
Careful control of the output power of transmitters and of repeaters, or optical amplifiers is therefore necessary. Other optical elements such as filters, attenuators, dispersion compensators, and so on may also need to be controlled bearing in mind the optical signal power requirements. The power gains and losses in the optical path, and in the various optical elements in the path, will vary with wavelength, age, and temperature. In some cases, the power will be affected by multiplexed signals being added or removed. For example, in optical amplifiers, the gain at each wavelength depends upon the pump power into the amplifier and on the number and power levels of the signals present.
Conventionally, to ensure that all signals in the transmission system do not suffer excessive degradation, the worst case sums of all these variations must be identified for a particular system, and a margin of error, a power margin, must be allowed for the worst case variations. This margin reduces the available performance of the system, for example reducing the maximum allowed transmission distances between repeaters or optical amplifiers.
It is known to control optical amplifiers to maintain a constant pump current, or a constant pump power, or a constant gain. However, the preferred type of control is constant total output power control. The control of gain in an optical amplifier such as an erbium-doped amplifier is discussed in U.S. Pat. No. 5,088,095. Undesirable gain fluctuations resulting from saturation effects in the amplifier are compensated in a number of ways. A feed forward automatic gain control loop acts on the pump source to increase the gain when a transient of higher signal power is detected at the amplifier input. A second method is to compensate for any variation of signal input by actively counter modulating the optical power of one of the input channels. Finally, it is suggested to feed back a selected wavelength from the output to the input. Ring lasing occurs at the feedback wavelength and consequently the gain in the amplifier is held at a constant value.
It is known from U.S. Pat. No. 5,513,029 (Roberts) to measure the relative output powers of different wavelengths in a wavelength division multiplexed (WDM) system, and control the individual wavelength powers. This document is not considered to be prior art under USC 102 as it originates from the same inventor and was published on Apr. 30, 1996.
In many situations, it will not be practical to control separately the output powers of different wavelength bands in a WDM system. Where it is only practical to control the overall output power of an optical element, or the power of two or more bands, there remains the necessity to allow for considerable power margins. For example, when more than one optical wavelength is amplified by an optical amplifier, a desired total power level may be set at 20 milliwatts. For four wavelengths, this gives a mean power of 5 milliwatts per wavelength. However, owing to gain variations including gain tilt, one wavelength may be at 17 milliwatts and another three may be at 1 milliwatt each. The 17 milliwatt signal will be severely degraded by non-linearities. This example is over simplified for the purpose of clarity.