A method and apparatus for storing associated data in a computing system having two or more storage devices arranged in a RAID configuration. The storage devices have a prewrite area for pre-storage of the data, and data region for persistent storage of the data. A scoreboard memory structure is created for monitoring the state of the prewrite area, and data in the prewrite area is conditionally invalidated based upon the information contained in the scoreboard memory structure. By conditionally invalidating the prewrite data, the write performance of the RAID storage system is improved.

1. Field of the Invention
This invention relates to efficient management and storage of data in a RAID disk array device or a RAID disk array in a computing system. More particularly, this invention relates to optimization of invalidation of data and parity information in a prewrite area of a RAID disk array.
2. Description of the Background
In computing systems designed for large data processing and data storage applications, redundant storage devices are provided to enhance the integrity of data maintained on the system in the event of a failure of a storage device.
For example, RAID (Redundant Array of Independent Disks) technology, such as RAID-1, RAID-4, and RAID-5, utilizes an array of disk drives which contain data and parity information distributed across each disk in the array. The parity information is additional information stored on the disks and can be used to reconstruct data contained on any of the drives of the array in the event of a single drive failure. In this manner, these RAID disk arrays can improve the data integrity of the computing system by providing for data recovery despite the failure of a single disk drive. However, because of the redundancy of information stored in the device, these RAID devices have been characterized by slow processing times for a single logical "write" of data to the RAID device.
RAID architectures can include a RAID device which is a standalone self-contained storage unit having multiple disk drives included therein arranged in a RAID array. The RAID information processing is performed internally to the device and is transparent to the computing system attached thereto. Alternatively, a computing system may have an array of disks and perform the RAID information processing within the processor of the computing system. Throughout this application, these architectures are referred to interchangeably, and the terms RAID device and RAID disk array are used interchangeably.
Regardless of the RAID architecture employed, data and parity information must be synchronously maintained in order to prevent corruption of data. There is a chance that parity and data for a region of a disk may get out of synchronization due to a system failure or crash. When this happens there is no indication of the problem until a disk drive fails, and the data returned on reads and writes from the RAID device will be incorrect.
In order to keep parity and data synchronized at all times, all write operations can be first placed in a "prewrite" area, having numerous prewrite slots, for temporary persistent storage, and then written to the actual logical blocks of the disk. This guarantees that if the host computer fails or crashes, or if the RAID device crashes, the data and parity can be kept in synchronization. The prewrite process uses the following steps:
1) write the data and parity to a prewrite area; PA1 2) write the data and parity to actual logical blocks of the disks; PA1 3) invalidate the data and parity in the prewrite area.
The "invalidation" step three is required to prevent data in the prewrite area from being erroneously backed up and corrupted by a system crash. Invalidation is defined as marking the prewrite data/parity as invalid or non-usable, preventing the information from being replayed upon initialization of the RAID array. Invalidation is performed after the parity and data stored in the prewrite slots have been physically written to their proper physical location on the RAID disk array. For example, a tag can be placed over each prewrite slot after the data/parity has been written to the disk indicating that the data/parity in the prewrite area is no longer valid and should not be used.
This unconditional invalidation step is expensive in time and performance, as it requires a separate disk write operation. The performance cost can be up to approximately 10 milliseconds per logical write operation to the RAID disk array.
FIG. 1 shows the steps disclosed in the co-pending application, "HOST-BASED RAID-5 AND NV-RAM INTEGRATION", referenced above, for performing a single "logical" write of new data in a RAID-5 device.
Operation 20 reads the old data from the disk, while operation 22 reads the old parity from the disk. Operations 20 and 22 are needed to calculate the new parity information. Operation 24 generates the new parity information by first removing the old data from the parity information, which can be achieved by an exclusive-OR operation. The new parity information is then generated by including the new data into the parity information, which can also be achieved using an exclusive-OR calculation.
Having calculated the new parity information corresponding to the new data, operation 26 records or "prewrites" the new data and the new parity to a prewrite region of the disk. In this manner, if the computing system is interrupted or if a single disk in the RAID array fails before the new data and new parity are both completed written to the disk, the new parity/new data information will always be synchronized. As previously explained, synchronization between data and parity is needed to correctly reconstruct data stored on a failed disk drive.
Having permanently recorded the new data and new parity in the prewrite area of the disk, this information can now be transferred to the respective storage locations on the disk drives. Operation 28 writes the new data to the disk, and operation 30 writes the new parity information to the disk. In this manner, both the new data and the new parity are now synchronously maintained on the disk drive.
Operation 32 marks the logical write operation to the RAID device as complete. This operation would include invalidating the data and parity information stored by operation 26 in the prewrite area of the disk. Upon a system failure, the data and parity information which are stored in the prewrite area can be used to restore data if that prewrite data/parity has not been marked invalid.
The invalidation step requires two write operations--one write operation to mark the prewrite data as invalid, and one write operation to mark the prewrite parity as invalid. This is in addition to the six disk input/output operations previously described. Hence, one logical write of new data to the RAID device would require eight physical disk input/output operations to the RAID device, a costly process.
What is needed is a device and method which is capable of minimizing the number of invalidating write operations while simultaneously ensuring the synchronization between parity and data on the RAID device.

Method and apparatus for maintaining data consistency in raid


A printing apparatus (10) employs electrostatic gripper plates (12, 14, and 16) to stepwise advance printing substrates (18) in a reciprocating shuttle fashion past a print head (22) that contains microchannels (33) that are filled with ink by capillary action awaiting, in concave shape at each microchannel orifice, print activation which is accomplished by imposing electrical fields at each electronically addressable orifice to cause the ink to protrude in a convex shape. To cause the paper to be marked, certain orifices are activated in accordance with imagewise information that is stored digitally in a memory which feeds data for the print head to cause the ink to protrude in varying thickness dimensions from the addressed orifices in proportion to the imposed field intensities with said protruding ink positions being transferred to the printing substrate surface in step by step fashion as the substrate advances and is between each step brought momentarily in contact with the print head orifices and then withdrawn therefrom, said ink being preferably of the hot-melted type so as to accomplish instantaneous fusion of the ink when it touches the printing substrate surface and solidifies thereon, thereby causing the formation of a novel lenticular image topography.

The present invention concerns printing. Its operating principles have particular, although not exclusive, applicability to portable color printers.
The printing art, which began in 1300 A.D., is quite mature. Vast amounts of research and expense have been dedicated to optimizing the quality and minimizing the cost of printing machines, particularly those intended for the consumer market. Given the difficulty of meeting the demands of the human eye, the results of these efforts have been largely satisfactory. Still, the techniques employed to achieve good enough results have tended to be complicated and expensive.
Printing devices early employed for office use to meet small-computer output needs employed hammers and print-stylus matrices. These were noisy and slow and produced low-quality output. Quality improved with the use of thermal printers, but these required special paper and tended to be slow, too. A greater quality advance accompanied the advent of xerographic or special-paper laser printers, but their mechanisms are complicated, and they remain relatively expensive despite the high volumes in which they have been produced. And none of these technologies lends itself well to low-cost-per-page, high-quality color imaging.
Ink-jet and ink-bubble technologies have addressed these shortcomings to a significant extent. Ink-jet printers squirt charged ink at the paper, deflecting the ink droplets electrostatically to direct it to the desired impact location. This approach is simple in comparison with say, laser printers, and it lends itself to color printing, since successive jets of different-colored ink can be applied to the same locations. Ink-bubble-jet approaches are similarly direct: they employ explosive energy to propel ink drops to the paper from an array of sources. But the ballistic nature of the ink delivery to the paper or other print substrate in both of these approaches tends to make the image quality quite dependent on the type of paper or other image medium.


An instrument for cutting hair comprises first and second members extending longitudinally in a direction generally parallel to a hinge axis 19 of a hinge that connects the two members. Each member has an arm and a leg. The legs have sockets in which tools are received. The arms comprise grip portions for grasping and actuating by a user""s hand. During use, the actuation of the arms moves the legs in an arcuate path of a common circle about the hinge axis 19. The legs and the tools disposed in the sockets of the legs have straight features that remain parallel to each other and to the axis 19 of the hinge during movement along the arcuate path. The instrument has a closed pinching or clamping position in which the tools meet each other in abutting relation. The method of using the instrument includes selecting tools from the group comprising razor blades, thinning blades and back guards, disposing selected tools in the sockets of respective legs, separating the legs, placing a lock of hair between the legs, clamping the tools on the lock of hair, and pulling or pushing the tool in a direction along the length of the hair to progressively cut hairs of the lock of hair.

1. Field of the Invention
The invention relates to haircutting instruments and methods of using the same primarily in barbershops and beauty salons.
2. Description of the Related Art
It is well known to use a straight blade in cutting and thinning hair. In the past this has been accomplished by placing an instrument with a blade on one side of a lock of hair and the user""s finger on the opposite side of the lock of hair. The user thus pinches or clamps the lock of hair between the blade and his or her finger. This is a tedious operation and requires great skill to prevent cutting one""s finger with the blade. The user must take care to avoid being cut while maintaining the proper amount of pressure and the proper angle of the blade with respect to the individual hairs in the lock of hair.
This procedure of pinching or clamping a lock of hair between the finger and a blade has the advantage of slicing the individual hairs at an acute angle which provides a softer feel at the hair ends and also inhibits the problem of the hair breaking. Another benefit of cutting the hair ends in this way is that it causes each individual hairs to lie more nicely within the lock of hair.
It can be seen that there is a need in the art for a device and a method that assures the safety of the user and provides a consistency in the angle of cut. There is a further need to provide an instrument and a method for cutting hair with a straight blade that is easy to use. Still further, there is a need to provide the above stated needs with an instrument that has easily replaceable tools including blades.
The instant invention overcomes these deficiencies with an instrument that is easy to use, safe, and provides consistency in the angle of the cut.
The instrument is comprised of two pieces or members that are coupled by a hinge having an axis. Each piece has an arm and a leg that are substantially parallel to each other and the axis of the hinge. The arm has grip portions and the leg has sockets for receiving tools. This allows the user to actuate the legs by manipulating the grip portions of the arms.
In use, the leg portions are separated by manipulating the grip portions. A lock of hair is placed between the tools that are positioned in sockets of the legs. The legs are then clamped onto the lock of hair by a gripping action and the instrument is pulled or pushed in a direction along the length of the lock of hair. This pulling or pushing action cuts individual hairs of the lock in the progressive manner as the instrument is moved away from the person""s head.
The legs have jaws that are substantially parallel to each other. The jaws in a fully clamped position are spaced apart to enable a lock of hair to slide between them. The jaws of the legs have sockets which receive tools. The tools comprise at least one cutting blade which can be a razor blade, a knife or a thinning tool. Tools also may include one back guard. Thus, the hair is clamped between two blades or a blade and a back guard so that when the instrument is pulled or pushed in a direction away from the person""s head, the hairs of a lock of hair clamped between the jaws are pinched by the tools and progressively cut as the instrument is moved away from the person""s head. The edges of the tools that engage the lock of hair are parallel to each other so that the lock of hair receives even pressure along the length of the tools.
In one aspect of the invention, the arms and legs of each member of the instrument are spaced radially with respect to the axis of the hinge. In another aspect the arms and legs are generally parallel to the axis of the hinge. Expressed another way, each arm and each leg extends along a line parallel to the hinge axis. With this construction, the arms and legs remain generally parallel to each other and to the hinge axis during the hinging action.
The tools may be two razor blades which meet in a parallel fashion at their distal edges. Alternatively, the tools may be two thinning blades which have teeth. These teeth meet each other similarly to the two blades. However, with the thinning blades there are spaces between the teeth through which individual hairs may pass as the instrument is pulled or pushed away from the person""s head. Thus, only some of the hairs are cut. Another alternative is to have one razor blade in the socket of one of the legs, and a back guard in the socket of the other leg. In this way the back guard and the razor blade meet in a pinching manner on the lock of hair. In practice, any combination of tools may be used in the instrument as long as one of the tools comprises a blade.
In another aspect of the invention, the instrument may be constructed such that the arms of the instrument are spaced at any preferred distance of comfort to the user. This spacing may be provided by the structure of the arms adjacent to the hinge wherein the arms abut each other and thereby space the finger loops from each other at a comfortable distance. Alternatively, stops may be provided at any location on the arms to mutually abut each other and provide the desired spacing.
As with a regular pair of scissors, the grip portion of the present invention may be provided by finger loops that lie generally in a common plane. However, it is contemplated that the grip portions may be angled to that regular plane by plus or minus 70 degrees about the hinge axis. The selection of these angles can be especially important because of the different manner in which this instrument is used as compared with regular scissors. That is, the forces required when pulling or pushing the instrument along the lock of hair are different from the forces required when using a regular pair of scissors. The forces required with the instant invention, in turn, affect the gripping requirements. Because of the gripping requirements of the instant invention, having finger loop angles different from those of regular scissor finger loops is desirable in at least some cases.
In use, a lock of hair may be placed between the tools in the instrument legs and the legs may be clamped onto the lock of a hair with light pressure. Depending on the angle of the tools, little or no pressure may be required to continue the cutting action along the length of the lock of hair, cutting the hair is effected by pushing or pulling the instrument away from the person""s head. The user may selectively apply more pressure to cut the individual hairs more rapidly or completely sever a lock of hair. Also a user may grasp the lock of hair between the instrument and the person""s head to minimize pulling on the hair at the scalp during the use of the instrument.

Haircutting instrument and method of use


A provisioning device may be shipped to a client and used to automatically provision an IoT device to join a local network to communicate with a remote service provider. In response to a trigger input, the provisioning device creates a wireless hotspot that is recognizable by an IoT device as a provisioning hotspot. The provisioning device receives a signal from the IoT device indicating that the IoT device is available to be provisioned. The provisioning device obtains provisioning data and transmits the provisioning data to the IoT device. The IoT device uses the provisioning data to connect to a local wireless network and to establish a connection to the remote service provider. The IoT device may then use one or more IoT services of the service provider.

With the increased availability of different smart devices that access the internet, many new applications have been developed that leverage internet connectivity. The Internet of Things (IoT) is a phrase given for the interconnection of computing devices scattered around the globe within the existing internet infrastructure. IoT devices may be embedded in a variety of products, such as home appliances, manufacturing devices, printers, automobiles, thermostats, smart traffic lights, etc. Many client devices make use of a long-lived connection with a server of a remote service provider in order to stream data from the client device to the server and from the server to the client device whenever data needs to be transmitted (e.g., publish-subscribe communication).
The process of provisioning an IoT device to connect to a service provider and to use services of the service provider can be a high-friction process. For example, configuring a local wireless connection, device authentication, and binding to a user account at the service provider can be a time-consuming and complex exercise. A user may be required to enter a large amount of data at multiple steps in order to provision an IoT device to establish a connection with a service provider and to begin using the IoT device. Therefore, the process can be error-prone, which often results in requiring a user to repeat the same step multiple times before successfully provisioning a given IoT device.
While embodiments are described herein by way of example for several embodiments and illustrative drawings, those skilled in the art will recognize that embodiments are not limited to the embodiments or drawings described. It should be understood, that the drawings and detailed description thereto are not intended to limit embodiments to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope as defined by the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word "may" is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words "include," "including," and "includes" mean including, but not limited to.

This patent is subject to a terminal disclaimer.


A flexible conduit for vehicle engine coolant circuits, which conduit comprises a series of at least a first relatively rigid portion and a second relatively deformable bellows portion capable of being deformed at least into a curved portion; and an inner and outer wall made of different plastic materials.

The present invention relates to a flexible conduit for vehicle engine coolant circuits.
Normally, engine coolant circuits feature rubber hoses which are preformed according to fitment inside the engine compartment, for connecting the engine, cooling radiator, holding and expansion tank, circulating pump, passenger compartment heating radiator, etc. Rubber hoses of this type present a number of drawbacks in terms of weight; transportation problems due to the need for preforming; aging resulting in cracks and/or failure of the hoses; and, consequently, relatively high production cost.

Flexible conduit for vehicle engine coolant circuits


An image forming apparatus according to an embodiment includes a charging device that charges an electric charge to an image carrier, a developing device supplying the image carrier with a developer, and a transfer device that transfers a toner image formed on the image carrier by a developing device onto a recording medium. The apparatus further includes a control unit, discriminates between a first mode of forming an image on a first recording medium of a first thickness and a second mode of forming an image on a second recording medium thinner than the first recording medium to control a developing contrast electric potential, and controls a magnitude of the developing contrast electric potential in the second mode so as to be lower than the first mode.

In an image forming apparatus such as a copier of an electrophotographic type, an image is formed on a recording medium (a sheet of paper and the like) by a cycle of charging, exposing, developing, and transferring. For example, a surface of a photoconductive drum is similarly charged, a laser beam is radiated to the charged photoconductive drum to form an electrostatic latent image, and the electrostatic latent image of the photoconductive drum is developed by a developing device to form a toner image.
The toner image of the photoconductive drum is primary transferred to a rotating intermediate transfer belt and the like, and the toner image is secondary transferred onto the sheet. The sheet, onto which the toner image is transferred, is heated by a fixer and a toner image is fixed on the sheet. The sheet, to which the toner image is fixed, is discharged by a transport roller.
Incidentally, in the image forming apparatus of the related art, an image can be formed on various recording media such as thick sheet, coated sheet, and thin sheet. Meanwhile, in order to be compatible with various recording media, an engine of the image forming apparatus needs to be designed so as to cope with the respective media. However, it is difficult to cope with various media from a thin sheet to a thick sheet with one engine.
Especially, in the printing on the thin sheet, a sheet may be wound around the fixer, or a sheet may be wound around a transfer belt or a transfer roller. In order to avoid the winding of the sheet, it is also considered to provide a transfer peeling portion or to provide a peeling claw in the fixer to facilitate the peeling, but there is a possibility that a claw mark is left on the sheet, which leads to an increase in costs.

Image forming apparatus and method of controlling image forming apparatus for more efficient printing


A drive package for acoustic transmitters includes a frame (6) of magnetic material with windows for accommodating driving members (20) and prestress devices (22) . Two windows with driving members and an intermediate window with a prestress device form a column which, by way of pressure studs (24) in the driving members and holes (14) in the frame, clamp pressure rods (4) located inside the transmitter against the shell (1) of the transmitter. The drive package may include several columns.

1. Field of the Invention
The invention relates to a drive package for acoustic transmitters Current acoustic devices are able to operate both as transmitters and receivers, that is, as measuring transducers for acoustic signals. An acoustic device in which the invention may be used to great advantage is as a so-called Sonar, that is, a transmitter which sends out sound waves under water which, after reflection, can be monitored by hydrophones of various kinds.
2. The Prior Art
It is a well-known fact that low-frequency sound waves can travel longer distances through water than can high-frequency sound waves. For a long time there has also been a considerable need for powerful low-frequency sound transmitters which are capable of working under water, both from a military point of view and from the point of view of the offshore oil and gas industry. Transmitters of various designs for these purposes and fields of use have been available on the market for quite a long time. A summary of such acoustic transmitters is given in an article in DEFENSE SYSTEM REVIEW, November 1984, pages 50-55 entitled "Sonar Transducer Design Incorporates Rare Earth Alloy".
Most acoustic transmitters which are used at present are based on either the piezoelectric effect or on magnetostriction. As is well-known, the piezoelectric effect means that a crystalline substance is subjected to a change in length when an electric voltage is applied to its end surfaces and that a voltage is obtained when the substance is subjected to a physical deformation, respectively. The magnetostriction means that a magnetic material which is subjected to a change of the magnetic flux suffers a change in length and that an externally caused change in length gives rise to a change in the magnetic flux, respectively. This means that a transmitter which utilizes these effects can also, in principle, be used as a receiver.
A variety of different embodiments of acoustic transmitters exist. In low-frequency applications it is common that they have a cylindrical shape with either a circular or elliptical cross section area.
The greatest problem with this type of transmitter is to achieve a sufficiently great amplitude of the oscillations. To this end, either a large transmitter area or a small transmitter area with great amplitude of oscillation would be required.
The introduction of the so-called giant magnetostrictive materials has improved the conditions for obtaining good acoustic transmitters. With such materials as driving elements, amplitude changes may be obtained which may largely amount to 100 times the corresponding changes using piezoelectric materials or using ordinary magnetic materials. Transmitters which utilize these giant magnetostrictive materials have existed on the market for several years.
A frequently occurring embodiment for the actual driving will be described in greater detail starting from a cylindrical transmitter with an elliptical cross section. The cylindrical envelope surface consists of an elastic diaphragm or shell. Inside and parallel to the axis of the cylinder and making contact with the shell are two rods applying pressure to the shell. The cross sectional area of the rods is symmetrically mirror-inverted in relation to the minor axis of the elliptical shell and each rod is delimited by that part of the shell which faces the end of the major axis and a chord parallel to the minor axis. Between the rods and making contact with their plane-parallel sides there is arranged an electrically controlled driving element in the form of a driving rod. The longitudinal axis of the driving rod coincides with the major axis of the elliptically formed cross section and lies midway between the end surfaces of the transmitter. In those case where the magnetostrictive effect is utilized, the driving rod consists of a magnetic material, suitably a giant magnetostrictive material, which with a surrounding winding is magnetized to keep pace with the desired frequency of the transmitter. If the piezoelectric effect is to be utilized, the driving rod is made of a piezoelectric material. The driving rod may, of course, consist in its entirety, or in certain parts, of a material with the desired possibilities of changing the length.
The fundamental embodiment of an acoustic transmitter described above may be different as regards the actual details. An acoustic transmitter with a cylindrical shape and with an elliptical cross section area and with driving rods of a giant magnetostrictive material is disclosed, inter alia, in U.S. Pat. No. 4,901,293 entitled "A Rare Earth Flextensional Transducer".
Swedish published patent application 8901905-3, entitled "Device in acoustic transmitters", also describes a cylindrical transmitter with elliptical cross section. The driving element consists of a body with oppositely located recesses into which pressure rods are inserted. The driving rods, in turn, are fixed into pressure rods which in the same way as above influence the diaphragm.


An optical micro-machining method of glass characterized in that after light is applied to glass including SiO.sub.2 and 30-70 mol % GeO.sub.2, the irradiated area is removed by etching.

This invention relates to an optical micro-machining method of glass by utilizing selective etching due to irradiation of light.
It is known that when a strong ultraviolet ray is applied to oxide glass, particularly SiO.sub.2 type glass, its density and refractive index become higher. It is also known that a similar phenomenon occurs on the surface of glass into which various ions such as transition metal ions are implanted. Generally, the area in which such a high density occurs has lower chemical durability than other areas. Therefore, when etching is carried out by an aqueous hydrofluoric acid solution, selective etching takes place in the light irradiated area. However, because the etching rate of light radiated glass is only about three times that of unprocessed glass, this rate is not yet sufficient for forming a diffraction grating or an optical waveguide on the glass surface or forming a fine pattern of an inorganic resist film on a semiconductor substrate.

Agency of Industrial Science & Technology


A cutting and welding system is disclosed which includes a metering system for controlling at a location remote from the plasma arc torch the amount of gas and water fed to the plasma arc torch. The system includes at least one torch having an electrode, a nozzle assembly positioned adjacent the discharge end of the electrode, and structure for generating a flow of gas between the electrode and the nozzle assembly to create plasma flow through the bore to a workpiece. A gas line communicates with a source of gas and the plasma arc torch for supplying gas to the torch. A plurality of metering orifices are positioned within the gas flow line in a parallel bank with each other so that the gas may flow through each of the metering orifices. Each metering orifice has a predetermined diameter opening. A gas control valve is mounted adjacent each of the metering orifices within the gas flow line on the upstream side toward the supply of gas. Each gas control valve is operable between open and closed positions for allowing gas flow through a metering orifice upon actuation of the valve. Control means selectively actuates the gas control valves to control gas flow through selected metering orifices to allow a predetermined amount of gas to flow to the plasma arc torch. A method of controlling the cutting current generated to the torch also is disclosed.

In a conventional cutting and welding system, plasma arc torches are supported on a frame bridge and carriage system. Drive means moves the plasma arc torches along the X - Y - Z axis during the cutting or welding of a workpiece positioned beneath the torch. A microprocessor controller, which usually includes a numerical control operating system, provides precise control over the position, movement, and acceleration of the torch to enable precision cutting and welding of the workpiece.
The plasma arc torches used in such systems usually are water assisted, although in some systems, the torches include an annular gas sheath generated around the discharged plasma instead of the usual annular jet of water. The torches also include water cooling circuits to prevent the torch from overheating during operation.
During system operation, a power supply generates a cutting current to the torch electrode, and generates an electrical arc extending from the electrode through a bore of the nozzle assembly of the torch into contact with the workpiece positioned beneath the nozzle assembly. A flow of cutting gas is generated between the electrode and the nozzle assembly, and the gas contacts the electrical arc to form a plasma flow through the bore.
During initial setup for system operation, the system operator presets the amount of cutting current and the amount of gas and water flow into the torch. The operator then manually adjusts the cutting current to accommodate load changes which occur through process parameter changes such as changes in plate thickness, changes in plasma gas flow, changes in the distance from the plate to the torch, and changes in the gas and water flows into the torch. In this system, each plasma arc torch includes a separate control for manually varying the cutting current and the gas and water flow into the plasma arc torch. A unitary control for several torches is not advantageous because of the inherent difficulty in balancing the gas, water and power between the different torches.
In many conventional systems, the water, gas and power controls are manually operated during system operation to enable the operator to set the flows and cutting currents on an as-needed basis. The controls usually are efficient and simple in design to reduce the overall cost of the system. In one conventional cutting and welding system marketed as a CM-300 Gantry Shape Cutting Machine, manufactured by ESAB Welding Products, Inc. of Florence, S.C., the gas and water pass through conventional rotameters and valve mechanisms associated with the rotameters. The operator visually measures the flow by reading indicia positioned on the side of the tapered measuring tubes common to the rotameters. The valves are adjusted accordingly.
The rotameters and the valves are usually positioned closely adjacent the torches. In one system, the tubes and valves are positioned in a flow control box mounted on the frame supporting the torches so that the tubes and valves move with the torches during cutting or welding, making manual adjustment of the gas and water flows during system operation difficult.
A more complex valve mechanism could be substituted for the conventional rotameters and valves. For example, a closed loop control system could be used for measuring water and gas output and complex valve mechanisms then could be adjusted for varying flow through the valves. However, such valves are complex and expensive, and require sophisticated control and software technology, making their use in a plasma arc torch welding and cutting system prohibitive.
In such manual water flow control systems, standard flow control valves also are positioned adjacent the water pumps to provide on-off control of water flowing into the torch. Typically, the valves are electrically actuated, and after extended use, the valves may become stuck in an open or closed position. If the torch is operated with a closed valve, the torch may overheat. Thus, operators often electrically bypass the flow control valve when the valve is open, hoping that the valve remains in the open position. If the valve closes, and the operator starts system operation under the belief that the valve is open, then the plasma arc torch will overheat, resulting in a damaged torch.
Additionally, in such cutting systems, a power supply provides a cutting current to the electrode to create a plasma flow through the bore to a workpiece positioned beneath the nozzle assembly. In one common power supply manufactured by ESAB Welding Products, Inc. of Florence, S.C., under the Serial designation ESP-400, the cutting current of this system is precisely regulated by an analog reference voltage signal.
The cutting current is a linear function of the analog reference voltage signal. The analog signal is adjusted by manually turning a small control knob, which varies the analog signal and varies the cutting current. During some cutting and welding operations, process parameters such as the thickness of the plate, the distance from the nozzle to the plate, and the operating temperature may change. As a result, the cutting current may vary as the process parameters change, and the operator must adjust the control knob to maintain a constant current output to the torch. Constant operator adjustment may result in some operator error, and the loss of cut or weld quality.

Plasma arc cutting system having fluid metering and power control systems


An image reading apparatus according to the present invention can obtain an image light from all areas of a document with uniform brightness, when receiving an image light from an area elongate in a first direction, and obtaining image data corresponding to the image information of a document by moving the image light area in a direction orthogonal to the first direction.

The present invention relates to an image reading apparatus which obtains image data from a reading object.
An image scanner obtains image data by opto-electrically converting a reflected light obtained by illuminating a sheet-like document, a book or a three-dimensional reading object, by an image reading sensor.
An image scanner is a transparent glass plate, for example, and includes a document holder (a document table) to hold a reading object placed on a document table, an illumination lamp, an illumination unit to illuminate a reading object placed on a document table, a line CCD sensor or an image reading sensor, and an image forming lens provided between a document table and a CCD sensor, to apply a reflected light from a reading object to a CCD sensor. An image forming lens is a reduction lens to reduce a reflected light of a reading width (length) defined as the length of one side of a document table, to meet the width (length) of the light receiving surface of a CCD sensor. In many cases, in an image scanner, by moving an illumination unit along a reading object fixed on a document table, a reflected light from a reading object is applied to the light receiving surface of a CCD sensor. Thus, an illumination lamp is made tubular long enough to illuminate the width of a reading object.
However, when a reduction lens is used, the intensities of the light passing through the center and periphery of a lens are not constant, and it is known that the light intensity lowers as the light shifts from the lens center, according to the well-known cosine biquadratic law.
Therefore, when a xenon lamp is used as an exposing lamp, for example, the shape of an external electrode is characterized to increase the light intensity in the area shifted away from the lens center. However, even if a xenon lamp with the external electrode shaped as above is used, it is difficult to make the illuminance uniform on the light receiving surface of a CCD sensor. Further, though it is proposed to compensate the influence of the cosine biquadratic law between the lights passing through the center and periphery of a lens when making shading compensation of the opto-electrically converted output from a CCD sensor, it has been know that the S (Signal)/N (Noise) ratio lowers in the light passing through the lens periphery.
Moreover, the characterizing the external electrode shape of a xenon lamp increases the cost of the lamp.


The invention is directed to techniques for dampening vibration of a disk drive using a dampening member which is co-planar with a mid-plane of the disk drive, and which has at least a portion extending from a carrier toward a main assembly when the carrier is installed within the main assembly in order to dampen vibration of the disk drive when the disk drive is in operation. The use of the dampening member in this location results in vibration dampening which is superior to conventional disk drive mechanisms. In particular, since the dampening member is co-planar with the mid-plane of the disk drive, the dampening member dampens vibration along a critical direction providing substantial vibration isolation. Accordingly, disk drives configured in accordance with the invention are capable of providing high performance even in high rotation speed (i.e., high RPM) and high density configurations.

A typical data storage system includes a cabinet that holds a configuration of disk drive mechanisms. Each disk drive mechanism generally includes a disk drive capable of storing and retrieving computerized data, and some form of housing or frame for supporting that disk drive within a support structure of the cabinet.
One conventional disk drive mechanism (hereinafter referred to as the xe2x80x9cplastic housing disk drive mechanismxe2x80x9d) includes a plastic housing, a disk drive, and an interface card. The plastic housing surrounds and supports both the disk drive and the interface card. The plastic housing includes ventilation channels along its vertical sides to allow air to pass over portions of the disk drive in order to cool the disk drive. A support structure for the conventional plastic housing disk drive mechanism typically holds several of such disk drive mechanisms in a two dimensional array (i.e., multiple rows and columns).
FIG. 1 shows another conventional disk drive mechanism 20 (hereinafter referred to as the xe2x80x9cmetal frame disk drive mechanism 20xe2x80x9d). The metal frame disk drive mechanism 20 includes a chassis 22, disk drive 24, and a disk drive connector 26. The chassis 22 supports both the disk drive 24 and the disk drive connector 26. The chassis 22 includes a metal frame 28, a plastic actuator 30 and two compressible disk shaped members 32-1, 32-2 (collectively, disk shaped members 32). The metal frame 28 includes a main section 34, and a secondary section 36 which is riveted to the main section 34. Each section 34, 36 is made of thin galvanized metal, which is stamped and bent to generally conform to the shape of the disk drive 24. As such, when the disk drive 24 attaches to the chassis 22, the main section 34 extends along a side of the disk drive 24 in a parallel manner. The plastic actuator 30 fastens to a central area of the main section 34. The two disk shaped members 32 attach to corners of the secondary section 36 which are farthest from the main section 34, as shown in FIG. 1.
A support structure (not shown) for the conventional metal frame disk drive mechanism 20 holds a row of such mechanisms 20. Multiple support structures can be stacked on top of each other within a cabinet to form a two dimensional array of metal frame disk drive mechanisms 20 (i.e., multiple rows and columns).
When a user installs a conventional metal frame disk drive mechanism 20 into a support structure, the user slides edges 38 of the main section 34 into slots of the support structure, and then actuates the plastic actuator 30. In response, the disk drive connector 26 engages a corresponding connector of the support structure, and the disk shaped members 32 compress tightly against the support structure to firmly hold the metal frame disk drive mechanism 20 within the support structure.
Unfortunately, there are deficiencies with data storage systems using the above-described conventional disk drive mechanisms. In particular, these mechanisms are susceptible to vibration caused by mechanical component movement (e.g., disk drive head movement) during operation. It has been observed that such vibration can be up to 10 times greater along a vertical plane in which the magnetic platters and the disk drive head move, relative to other directions (e.g., horizontally, side-to-side, etc.). Random seek operations have been determined to provide particularly high vibration (e.g., rotational vibration in the plane of the platter and head movement). Such vibration can prevent the head from positioning itself properly relative to a magnetic platter of the disk drive. As a result, the platter must continue turning to enable the head to re-attempt to properly position itself (e.g., in order to read or write properly), thus lowering performance (e.g., access speeds).
Poor seek times due to disk drive vibration problems are, at least in part, a result of inadequacies in the supporting structure of the disk drive mechanism. For example, in connection with the conventional plastic housing disk drive mechanism, the plastic housing tends to stress and distort based on movement of the disk drive. Such movements (e.g., disk drive vibration due to head movement) are difficult to control using the plastic housing due to low modulus of elasticity in the plastic itself (e.g., uncontrolled energy absorption).
As another example, in connection with the metal frame disk drive mechanism 20, the metal section 34 in combination with the two disk shaped members 32 attempt to counteract the disk drive vibration. However, such vibration dampening is difficult to achieve due to the different approaches to supporting the disk drive mechanism 20 within the support structure used by the metal frame disk drive mechanism 20, i.e., a vertical metal section 34 on one side, and rubber disk shaped dampening members 32 on the other side.
Moreover, these conventional disk drive mechanisms have become more susceptible to vibration in recent years due to increases in disk drive rotation speeds (e.g., faster movement of internal mechanism components such as heads moving along magnetic platters spinning at faster rotations per minute or RPMs) and increases in disk drive densities (e.g., no longer using a dedicated platter for location tracking but instead using stripes/spokes to increase storage capacity). When used with conventional disk drive mounting mechanisms, such advances in disk drive technology have reduced the ability of disk drive heads to properly position themselves (i.e., read markings on the magnetic platters), and thus have made disk drives more susceptible to vibration problems.
In contrast to the above-described conventional disk drive mechanisms, the invention is directed to techniques for dampening vibration of a disk drive using a dampening member which is co-planar with a mid-plane of the disk drive, and which has at least a portion extending from a carrier toward a main assembly when the carrier is installed within the main assembly in order to dampen vibration of the disk drive when the disk drive is in operation. The use of the dampening member in this location results in vibration dampening which is superior to conventional disk drive mechanisms. Accordingly, disk drives configured in accordance with the invention provide high performance even in high rotation speed (i.e., high RPM) and high density configurations.
One arrangement of the invention is directed to a data storage system having a main assembly for holding multiple disk drive assemblies, and a disk drive assembly. The disk drive assembly includes a disk drive that stores and retrieves computerized data and a carrier coupled to the disk drive. The carrier supports the disk drive within the main assembly. The disk drive assembly further includes a dampening member coupled to the carrier at a location of the carrier which is co-planar with a mid-plane of the disk drive. At least a portion of the dampening member extends from the carrier toward the main assembly when the carrier is installed within the main assembly in order to dampen vibration of the disk drive when the disk drive is in operation. Since the dampening member is co-planar with the mid-plane of the disk drive, the dampening member dampens vibration along a critical direction providing substantial vibration isolation.
In one arrangement, the disk drive assembly further includes a lever that selectively (i) engages the disk drive assembly with the main assembly, and (ii) disengages the disk drive assembly from the main assembly. In this arrangement, the disk drive assembly further includes hardware which pivotably couples the lever to the carrier, and a dampening bushing which is positioned between the lever and the carrier by the hardware, in order to dampen vibration between the lever and the carrier. Here, the dampening bushing provides additional vibration isolation thus improving disk drive performance.
In one arrangement, the lever operates with the dampening member of the disk drive assembly to provide cantilevered support for the carrier of the disk drive assembly when the lever engages the disk drive assembly with the main assembly. Such support is superior to that of the conventional chassis disk drive mechanism which simply uses rubber disk shaped members in corners of one vertical side of a thin, galvanized metal frame. Accordingly, there is less vibration in the disk drive assembly of this arrangement.
In one arrangement, the main assembly includes connectors, and the disk drive assembly further includes a circuit board, coupled to the carrier, that mates with a connector of the main assembly. The circuit board provides friction between the carrier and the main assembly in order to dampen the vibration of the disk drive (e.g., in order to dampen vibration of a cantilevered end of the carrier) when the carrier is installed within the main assembly and when the disk drive is in operation. Accordingly, the circuit board improves the vibration isolation of the disk drive assembly.
In one arrangement, the main assembly includes support ribs, and the carrier of the disk drive assembly includes a set of guides that position a support rib of the main assembly along an area of an outer surface of the carrier. This area is co-planar with the mid-plane of the disk drive. The increase in contact area between the carrier and the main assembly, which is focused along the mid-plane of the disk drive, provides improved vibration dampening. Accordingly, the disk drive performance is improved and the design is less susceptible to increases in disk drive speed and density.
In one arrangement, the carrier of the disk drive assembly is formed by stamping, bending and welding a metal sheet into a single, contiguous metallic frame. This arrangement provides stiffness which is superior to that of the metal frame of the conventional metal frame disk drive mechanism, and that of the plastic housing of the plastic housing disk drive mechanism. Accordingly, this arrangement provides superior control over disk drive movement and energy absorption for improved vibration dampening.
The features of the invention, as described above, may be employed in data storage systems, devices and other computer-related components such as those manufactured by EMC Corporation of Hopkinton, Mass.

Methods and apparatus for dampening vibration of a disk drive


A backlight driving circuit and a liquid crystal display device are disclosed. The backlight driving circuit is utilized for driving at least one light emitting diode bar and includes a power supply module, a conversion module, a comparison module, and a control module. The power supply module provides a driving current for the light emitting diode bar. The conversion module generates a conversion voltage according to the driving current. The comparison module compares the conversion voltage with a reference voltage. The control module controls whether the power supply module provides the driving current for the light emitting diode bar according to whether the conversion voltage is greater than the reference voltage. The backlight driving circuit and the liquid crystal display device of the present invention can limit the driving current flowing through the light emitting diode bar.

1. Field of the Invention
The present invention generally relates to a driving circuit, and more particularly to a backlight driving circuit and a liquid crystal display device having the backlight driving circuit.
2. Description of Prior Art
A liquid crystal display device mainly comprises a liquid crystal panel and a backlight module. The backlight module is utilized for providing light when the liquid crystal panel displays an image. Light emitting diodes (LEDs) are utilized as a light source in the conventional backlight module. More particularly, a conventional light source comprises a plurality of light emitting diode bars which are electrically coupled in parallel. Each of the light emitting diode bars comprises a plurality of light emitting diodes which are electrically coupled in series.
In the above-mentioned conventional backlight module, a backlight driving circuit provides a required driving current for driving all of the light emitting diode bars. However, the driving current flowing through the light emitting diode bars cannot be limited by the conventional backlight driving circuit. When a false condition occurs and the driving current is too high, the light emitting diode bars and the backlight driving circuit are destroyed by the high driving current.
Consequently, there is a need to solve the problem that the light emitting diode bars and the backlight driving circuit are destroyed by the high driving current resulted from the false condition because the driving current flowing through the light emitting diode bars cannot be limited in the prior arts.

Backlight driving circuit and liquid crystal display device

SHENZHEN CHINA STAR OPTOELECTRONICS TECHNOLOGY CO. LTD.


In a wireless communication system (100, 200), at least one service building block (605-610 and 622) is used in a service creation environment (301) to create logic program rules (303) that include identification of an authorized service execution environment. The logic program rules, which may require further configuration, are provided to a service execution environment (302) having an identification that matches the identification of the authorized service execution environment. Configurable software modules within the service execution environment are executed in accordance with the logic program rules when at least one predetermined stimulus is detected, thereby providing the service within the system. The service creation environment and the service execution environment may be implemented within a single console or separately implemented within different consoles, or the service creation environment can be embodied within a stand-alone computer (201). In this manner, rapid service creation is provided.

Wireless communication systems are well known in the art. Within such systems, a fixed infrastructure is used to provide a variety of services to wireless units (e.g., mobile and/or portable radios). In many systems, particularly conventional and trunked land mobile radio systems, the fixed infrastructure includes one or more consoles (or operator positions). A console allows a dispatch operator to coordinate communications among the wireless units, as well as to communicate with the wireless units. As an example of a service within a console-equipped system, a dispatch operator can create temporary talk groups (logical groupings of wireless units created for the purpose of group-wide communications) and exchange communications with members of the temporary talk group. The ability to creatte temporary talk groups (often referred to as "patch") is useful, for example, when responding to emergency conditions. A variety of other services akin to the creation of temporary talk groups are also commonly available, such as emergency alarm, emergency call, private conversation, and call alert.
However, the use of any given service is limited by the particular service logic available to the communication equipment that implements the service, e.g., the console. The software available to the equipment typically limits the use of services in that the services may not be modified to fit the needs of a particular user or to meet the needs of a given set of circumstances. Currently, whenever a new service is required by a user of a wireless system, the manufacturer of the wireless system must first engage in an expensive and time-consuming process of designing and testing the new service before providing the service to the user. As the sophistication of the new services increases, the cost, complexity and time required to provide such new services correspondingly increases. Although not currently possible, it is recognized that it would be desirable to allow new services to be implemented "on the fly" by users as the need for such new services become apparent.
Various standards bodies, such as the International Telecommunications Union (ITU-T), have made recommendations for the so-called Intelligent Network, and have begun to generally outline the concept of a "Rapid Service Creation Environment". Strides have been made in "rapid service creation" in the area of wireline networks, i.e., telephone networks. For example, U.S. Pat. Nos. 5,315,646 and 5,345,380 to Babson et al., 5,323,452 to Dicikman et al., and 5,481,601 to Nazif et al. illustrate various methods and apparatuses for the creation and provisioning of unique call services in telephone networks. In general, these patents describe a system in which a hardware interface (e.g., a computer with a display terminal) is provided that allows a user to manipulate abstract building blocks and thereby create, simulate and provide new telephone-based services. However, these techniques are limited to wireline environments.
Additionally, the services created using these techniques are not executable by the platform that is allowed to create them. That is, the actual execution of the newly created services must be distributed to other network entities, such as telco switches and service control points. This is a suitable limitation in a telephone system comprising a large number of processing devices. However, such a distributed implementation is not cost-scaleable to smaller, wireless communication systems in which there is a relatively small number of processing devices within the fixed infrastructure. Furthermore, a limitation of wireless communication systems is the presence of noise, interference and other factors that limit performance within the system. The presence of these limiting factors, not otherwise found in wireline systems, gives rise to special processing needs such as message retries and exception handling. In view of these limitations of the prior art and the circumstances typically arising in wireless systems, there exists a need for techniques that provide rapid service creation in wireless communication systems.

Method and apparatus for implementing a service in a wireless communication system


Printed circuit boards that include optical interconnects include a flexible optical waveguide embedded or locally attached to the board having at least one end mechanically decoupled from the board during fabrication that can be fitted with a mechanical connector. Also disclosed are processes for fabricating the circuit board.

1. Field of the Invention
This invention generally relates to mechanically decoupled opto-mechanical connectors for flexible optical waveguides embedded and/or attached to a printed circuit board. More particularly, the invention relates to improvements of an optical interface between the waveguides in an optical printed circuit board and associated opto-electronics or passive optics thereon.
2. Description of Background
Printed circuit boards (PCBs) generally include multiple integrated circuits mounted upon their surfaces. PCBs typically contain multiple conductive and dielectric layers interposed upon each other, and interlayer conductive paths (referred to as vias), which may extend from an integrated circuit mounted on a surface of the PCB to one or more conductive layers embedded within the PCB.
The speed and complexity of integrated circuits are increasing rapidly. As the number of components per chip, the number of chips per board, the modulation speed and the degree of integration continue to increase, electrical interconnects are facing fundamental limitations in areas such as bandwidth, bandwidth density, bandwidth times length product, packaging, and power consumption.
The employment of optical interconnects will be one of the major alternatives for upgrading the interconnection speed whenever conventional electrical interconnection fails to provide the required bandwidth. However, the introduction of optics and the required optical connections into the PCB causes problems due to the substantially different requirements than those of commonly utilized electrical interconnects, mechanical connectors, thermal interfaces, and the like. One problem is the proper connection of the waveguides in the board with waveguides in other boards, with opto-electronic modules on board, and with test equipment such as fiber bundles. For example, connections between the opto-electronic subassembly and the PCB would require electrical lines with high speed capability to the PCB, an optical coupling to the waveguides, mechanical connectors between the opto-electronic subassembly and the PCB as well as a thermal interface to the heat sink. Connections between boards would require optical connections with precise alignment, electrical lines, and rugged mechanical connections. Connection between the board and the test equipment would require optical connection with precise alignment and compatibility to standard fiber bundles. The different connections as noted above and the specific properties required for the connections, i.e., electrical, thermal (different coefficients of thermal expansion between dissimilar materials), and the like as well as the large tolerances in current PCB manufacturing processes, lead to numerous potential problems. For efficient optical coupling, the alignment accuracy of multimode polymer waveguides has to be in the range of 5 to 10 micrometers, whereas current PCB tolerances are in the range of about 100 micrometers.
Accordingly, there remains a need for improvement of the optical interface between an opto-enhanced printed circuit board and associated electronics thereon.

Mechanically decoupled opto-mechanical connector for flexible optical waveguides embedded and/or attached to a printed circuit board

International Business Machines Corporation


The present disclosure relates generally to a light emitting diode (LED) luminaire. In one embodiment, the LED luminaire includes a base, a heat sink coupled to the base, a power supply coupled to an interior volume of the heat sink, one or more LEDs coupled to the power supply, wherein the one or more LEDs are coupled to a circuit configured to provide a constant input impedance and a lens coupled to the heat sink and enclosing the one or more LEDs.

Presently, much lighting used for applications such as rail lighting, for example, still uses incandescent light bulbs. However, incandescent light bulbs are inefficient and need to be replaced regularly. Some applications may use a very large number of incandescent light bulbs. As a result, if the light bulbs regularly fail, having a large number of incandescent light bulbs creates a high cost due to both the cost of the new bulb and labor associated with its replacement.
In addition, some lighting systems require the incandescent light bulbs to be electrically connected in series. Traditional incandescent light bulbs can be connected in series across an AC or DC power supply. This allows lights to be used where the only supply available may be much higher than the voltage rating of the lights. Since the impedance of the incandescent light bulbs is constant, each receives an equal share of the total voltage and so operate predictably. Furthermore, since a filament bulb is a resistive load when connected in a serial string across an AC supply, power factor is unity.
However, other types of light sources may not behave as a traditional incandescent light bulb behaves when connected in series. As a result, simply replacing an incandescent light bulb with another type of light source is not trivial. For example, other types of light sources may have features of their behavior that prevent proper operation if electrically connected in series.

Light emitting diode luminaire for connection in series


The invention relates to a rotor having at least three blades disposed between a front cover plate and a rear cover plate, the art of the suction edge of at least one blade, in the top view of the inlet side of the pumping medium, following a sinusoidal path with a single turning point W. The present invention is also directed to the use of the rotor in a centrifugal pump to pump coolant in a motor vehicle.

The invention relates to a rotor for a centrifugal pump and to a use of the rotor.
Rotors for centrifugal pumps are known. They are provided with blades through which the pumping medium, which is introduced perpendicular to the blades, is diverted in the radial direction and is led off laterally from the rotor to the pressure branch pipe of the centrifugal pump. A particularly high importance is herein attached to the structural design of the blades. In "Strömungsmaschinenn" by Karl Pfleiderer, Hartwig Petermann, 6th edition, pages 156 to 165, aspects are set out according to which the blades should be structured. It is herein emphasized, for example, that the path of the suction edge of the blade should be chosen such that it connects to the side walls at the steepest possible angles, at sufficient distance from the pressure edge.


In one aspect, the present invention concerns a process of making coated magnetic particles. According to this process, an aqueous sol of amorphous, hydrolyzed, aluminous, colloidal particles is mixed with an aqueous suspension comprising magnetic particles. The amorphous, hydrolyzed, aluminous, colloidal particles have a mean particle size in the range from about 0.5 to about 5 nanometers and an average degree of hydrolysis in the range from 1.5 to about 3. During mixing, the amorphous, hydrolyzed, aluminous, colloidal particles form a continuous, amorphous, aluminum hydrous oxide coating on the magnetic particles, wherein the coating has an average thickness in the range from about 0.5 to about 5 nanometers. The present invention also concerns coated magnetic particles. Coated magnetic particles according to the present invention comprise a magnetizable core and a continuous, amorphous, aluminum hydrous oxide coating formed on the magnetizable core. The coating has an average thickness in the range from about 0.5 to about 5 nanometers. In another aspect, the present invention concerns a magnetic recording medium comprising a magnetic layer formed on a nonmagnetizable support. The magnetic layer comprises the coated magnetic particles described above dispersed in a polymeric binder.

Magnetic recording media generally comprise a magnetic layer coated on at least one side of a nonmagnetizable support. For particulate magnetic recording media, the magnetic layer comprises magnetic particles dispersed in a polymeric binder. The magnetic layer may also include other components such as lubricants; abrasives; thermal stabilizers; antioxidants; dispersants; wetting agents; antistatic agents; fungicides; bactericides; surfactants; coating aids; nonmagnetic particles; and the like.
The magnetic layer of a majority of conventional magnetic recording media is prepared by combining the magnetic particles, the polymeric binder, and other components (if any) with an organic solvent to form a dispersion. The dispersion is generally homogenized by lengthy mechanical milling to break up agglomerates of, and disperse, the magnetic particles. The resulting dispersion is then coated onto the nonmagnetizable support. The magnetic particles may then be magnetically oriented after which the coating may be dried, calendered, and/or cured.
The quality of the dispersion plays a vital role in determining the electromagnetic performance of the resulting magnetic recording medium. If the magnetic particles are insufficiently dispersed in the polymeric binder and other ingredients of the dispersion, electromagnetic and physical properties of the magnetic layer, such as the signal to noise ratio, squareness ratio, ability to reproduce short wavelengths, magnetic particle packing density, Young's modulus, surface smoothness, abrasion resistance, durability, and the like, tend to suffer dramatically.
Uniform dispersion of magnetic particles in the dispersion is very difficult to achieve, particularly when extremely fine, platelet-shaped magnetic particles, e.g., barium ferrite particles, are used. Organic dispersing agents have been used to facilitate the dispersing of the magnetic particles. However, due to the magnetic attractive forces between magnetic particles, there is a strong tendency for magnetic particles to reagglomerate in the dispersion when milling stops, even when organic dispersing agents are used. Additionally, the performance of organic dispersing agents at dispersing the extremely fine, platelet-shaped magnetic particles having a particle size of about 300 nm or less has been disappointing. To be effective at dispersing such particles, dispersing agents have had to be used in amounts that tend to weaken the adhesion of the magnetic layer to the nonmagnetic substrate, thus adversely affecting the abrasion resistance and durability of the medium. For these reasons, new technology for improving the dispersibility of magnetic particles is highly demanded.
Covering magnetic particles with an inorganic coating has been used to reduce the tendency of magnetic particles to agglomerate or aggregate. For example, U.S. Pat. No. 4,707,593 describes a visible image magnetic card in which magnetic particles and a fine fluidizing powder are combined in a display cell. A portion of the fluidizing powder covers the surfaces of the magnetic particles. The fluidizing powder reduces the adhesion and friction coefficient between the magnetic particles. The fine fluidizing powder is selected from materials which may include aluminum oxide.
U.S. Pat. No. 4,438,156 describes a method for coating magnetic particles with colloidal silica particles. To prepare the coated magnetic particles, the magnetic particles are mixed with an acid at a pH such that the magnetic particles have a significant, positive electrostatic charge. The pH of a slurry of the colloidal silica particles is adjusted so that the colloidal silica particles have a significant, negative electrostatic charge. When the slurry of colloidal silica particles is added to the acidic mixture of magnetic particles, the colloidal silica particles with their negative electrostatic charge are attracted to and coat the magnetic particles with their positive electrostatic charge.
U.S. Pat. No. 5,039,559 describes coating magnetic particles with inorganic oxides, which may include aluminum oxide. The particles either are superparamagnetic or have a low Curie point such that the particles have low permanent magnetization. The coated particles are prepared by emulsifying an aqueous solution or dispersion of magnetic material and an aqueous solution or sol of the inorganic oxide in an inert, water-immiscible liquid. The aqueous droplets that form are gelled, recovered, and heated at 250.degree. C. to 2000.degree. C. The coating is continuous and covers the entire surface of the particle core to prevent exposure of the core to the surrounding media. The coated particles typically have a magnetic material content of below 50% by weight. Example 7 of U.S. Pat. No. 5,039,559 describes an Al.sub.2 O.sub.3 /LiFe.sub.5 O.sub.8 coating having a thickness of 10 nanometers.
U.S. Pat. No. 4,400,432 describes treated, ferromagnetic iron oxide particles in which the particles are coated with one layer of oxygen-containing anions and a further layer of polyvalent cations. The polyvalent cation layer may be applied between two oxygen-containing anion layers. The materials used to form the layers include water-soluble aluminum salts.
U.S. Pat. No. 4,229,234 describes the preparation of passivated particulate high Curie temperature magnetic alloys. An element, such as aluminum, is alloyed with iron, cobalt, or nickel. The alloy is then formed into particles, and the particles are then exposed to controlled amounts of oxygen at elevated temperature over selected time periods. An oxide of the element forms and diffuses to the surface of the particles to form a film. The films typically have a thickness in the range from 0.1 to 0.5 .mu.m.
U.S. Pat. No. 4,512,682 describes the formation of insulating layers comprising alternating layers of alumina and silica coated on a ferrite substrate.
U.S. Pat. No. 4,336,310 describes silica coated metallic magnetic powders and their use in recording media, which have further layers of silanes and oleic acid coated thereon.
U.S. Pat. Nos. 4,133,677, 4,280,918, 4,309,459 and 4,321,303 describe iron oxide fine powders having a silica layer formed on the surface thereof.
U.S. Pat. No. 3,535,245 describes metal oxide coated ferromagnetic particles prepared by a microgel process involving epoxy materials, an alumina gel, and ferromagnetic particles.
U.S. Pat. No. 4,944,802 describes the use of barium ferrite pigment particles in combination with inorganic oxide particles dispersed in a binder. The inorganic oxide particles are used as an abrasive and are not used to coat the barium ferrite pigment particles.
Japanese Kokai No. 1-119,519 describes magnetic particles coated with a layer of hydrated alumina with a boehmite structure. A coupling agent layer is then further deposited onto the surface of the coated particles.
Similarly, Japanese Kokai No. 1-176,229 describes magnetic particles having hydrated alumina shells composed of boehmite particles that are further overcoated with a layer of silica. It also describes magnetic recording media containing such coated particles.
Japanese Kokai No. 61-222,207 describes magnetic particles coated with aluminum oxide alumina sol shells useful in compression molding of magnetic objects. The aluminum oxide shell thicknesses were in the range of 1 to about 10 microns, with the thicker layers being preferred.
WIPO published patent application 90-15,364 describes a process for making non-smearable colored magnetic particles that comprises the steps of providing magnetic core particles of metal or reducible metal oxide 1-50 microns in size, depositing submicron particles of a non-reducible oxide of a different metal on the core particles, heating the aggregate particles in an oxygen-containing atmosphere to oxidize the surface of the core particles, and heating the particles sufficiently in an inert atmosphere to cause reaction between the core surface oxide and the deposited oxide, thus forming the surface colored magnetic core particles.
U.S. Pat. No. 2,085,129 describes the production of colloidal metal hydroxides. The colloidal metal hydroxides can be obtained by causing salts of trivalent metals, e.g., aluminum, to act in approximately stoichiometrical ratio on agents that decompose the salts to form hydroxides. The sols obtained by this process, e.g., alumina sols, are described as being useful as protective colloids (See page 4, first column, lines 33-40).
The adsorption of a polynuclear cation or positively charged colloid onto another positively charged colloid has been described in (a) "A Surface Precipitation Model for the Sorption of Cations on Metal Oxides", Farley, K. J.; Dzombak, D. A.; Morel, F. M. M. J. Colloid Interface Sci. 1985, 106, 226; (b) "Adsorption of Al(III) at the TiO.sub.2 -H.sub.2 O Interface", Wiese,G. R.; Healy, T. W. J. Colloid Interface Sci. 1975, 51, 434; and (c) "Adsorption of Hydrolyzable Metal Ions at the Oxide-Water Interface", James, R. O.; Healy, T. W. J. Colloid Interface Sci. 1972, 40, 65.
Some of these prior art techniques rely on crystalline materials, e.g., boehmite and pseudoboehmite, to coat magnetic particles. Crystalline coating materials, however, tend to provide coatings that are discontinuous and/or too thick. With a discontinuous coating, only part of the surface of the magnetic particles is covered by the coating materials. Unless the particles are further coated by layers of additional coating materials, discontinuous coatings provide particles having two different surfaces which must be wetted in order to disperse the particles. Discontinuous coatings, therefore, provide magnetic particles that are more difficult to disperse than particles having only a single kind of surface for wetting. When the coating is too thick, e.g., having a thickness of greater than 5 nm, the tendency of the magnetic particles to form aggregates may be reduced. However, the packing density of the magnetic particles is also significantly reduced. In view of this reduction in packing density, magnetic particles having such thick coatings would be less suitable for high density magnetic recording applications relative to magnetic particles having thinner coatings.
Other prior art techniques rely on gelation to coat the magnetic particles and are capable of providing continuous coatings. However, such coatings tend to coat large agglomerates of particles rather than individual particles and also tend to provide coatings that are too thick.
Other prior art techniques depend upon electrostatic attraction between the coating materials and the magnetic particles to achieve coating. This approach, however can only be used with certain kinds of magnetic particles having the proper surface charge characteristics. Moreover, this approach often requires a pH change to achieve coating. Changing the pH to achieve coating may destabilize the aqueous magnetic suspension and can cause poor quality, thick coatings to form on the magnetic particles. This approach can also degrade the magnetic properties of the magnetic particles.
Other miscellaneous coating techniques have also been described. What is needed in the art, however, are improved coating techniques that allow thin (i.e., 5 nm or less), continuous coatings to be formed on any kind of magnetic particle, regardless of its surface charge characteristics and without requiring gelation or a pH change to effect such coating.

Magnetic recording media prepared from magnetic particles having an extremely thin, continuous, amorphous, aluminum hydrous oxide coating


Briefly stated, the present invention provides a kit which facilitates the removal of obstructions, such as broken files, from the root canal of a patient during an endodontic or root canal procedure. The kit includes a trephine sized to be inserted in the root canal and adapted to widen the root canal around the obstruction to expose the obstruction and an obstruction removal tool adapted to engage and mechanically grasp the obstruction to remove the obstruction from the root canal. The obstruction removal tool includes a hollow tube and a plunger slideable within the tube. The hollow tube is sized to be inserted into the root canal a distance sufficient to receive the obstruction within its lumen. A cutout is spaced from the end of the hollow tube, and the hollow tube is slid over the obstruction a distance sufficient to generally align the top of the obstruction with the cutout. A plunger having a beveled end is slid through the hollow tube. The beveled end of the plunger engages the obstruction and urges the obstruction into the cutout so that the tool will mechanically grasp the obstruction. Once the tool has mechanically grasped the obstruction, the tool with the obstruction can be removed from the root canal.

This invention relates to a method for retrieving obstructions, such as broken instruments, from the root canals of human teeth, during endodontic and retreatment procedures. Specifically, the invention relates to a set of microendodontic instruments precisely designed and machined to remove a broken instrument from deep within the root canal space.
The human tooth contains a clinical crown and root. The crown portion has a thin outer layer of enamel which covers the underlying tubular dentine. The root's outer layer is comprised of a thin layer of cementum which covers the radicular dentine. Harbored deep and generally running central within these hard tissue structures is the soft tissue called the dental pulp which provides the vascular support and neural supply for the human tooth.
Throughout life, the dental pulp is vulnerable to injuries from decay (microbial), trauma (physical injuries), extensive dental procedures, or in certain instances, periodontal disease. These injuries singularly, or in combination, predispose the dental pulp to a cascade of pathological conditions beginning with inflammation and concluding with necrosis.
When these events transpire, patients may present in a dental office with clinical symptoms which, often times, demonstrate abnormalities of the soft tissue, supporting structures, and/or exhibit radiographic evidence of bone loss. The treatment options include palliative emergency care, endodontics (i.e., root canal treatment), or extraction. In other instances patients present with signs and/or symptoms associated with a failing endodonitically treated tooth that requires retreatment or extraction.
To avoid extraction of the tooth, root canal treatment or retreatment is performed. The root canal treatment is directed towards the elimination of pulp, bacteria, and irritants from the root canal system, followed by filling the canal space with an inert, biocompatible, dimensionally stable, root canal filling material. The clinical chain of treatment events are typically anesthesia and isolation procedures followed by cleaning and shaping procedures ideally culminating in three-dimensional obturation of the complex root canal space.
Canal preparation is accomplished utilizing instruments commonly referred to as "files". Manufacturers provide the doctor with a great variety of file choices ranging from different metals to flute configurations and geometries, tapers, lengths, and handle designs. Additionally, files can be used by hand or rotary instrumentation techniques. During cleaning and shaping procedures, the potential for file breakage is always present. File breakage is further impacted by the quality of manufacturing of the instrument used, the metallurgical properties of the metal from which the instrument is made, the number of times an instrument has previously been used, the degree of calcification, curvature, and length of a particular root canal system, patient cooperation, and importantly, method of use.
Historically retrieving broken instruments or other intercanal obstructions, such as gates glidden drills, lentulo spirals, silver points, and obturation carriers, posed formidable challenges. A broken instrument clearly compromises the prognosis of a case. The instrument can break at any point in the canal. If the coronal end of the broken instrument is near the crown of the tooth, the instrument can be removed fairly easily using traditional or conventional techniques. However, if the instrument breaks deep within the root canal, for example, where the canal begins to bend or curve, extraction of the instrument becomes much more difficult. Currently available retrieval instruments used to retrieve broken instruments cannot reach deep into the root canal, and thus cannot be used when the broken instrument is deep within the root canal. Because the practitioner was still in the process of cleaning and shaping the root canal, there can be bacteria, pulp, endotoxins, etc. deeper in the root canal that still needs to be removed. Thus, breakage of the instrument deep within the root canal can severely impact the outcome of the endodontic procedure.
Typically, the patient is faced with two options when the instrument breaks deep within the root canal. One option is extraction of the tooth. The other option is apical surgery to seal off the end of the root to prevent the bacteria, pulp, edotoxins, etc. from leaking out the end of the root canal.
Over time various retrieval techniques evolved that were crude, often times ineffective, and limited by restricted space. Frequently, efforts directed towards instrument retrieval, even when successful, weakened roots due to overzealous canal enlargement, which in turn predisposed the tooth to subsequent root fractures and, ultimately, the loss of a tooth. Additionally, attempting to remove a broken instrument can lead to serious iatrogenic events, such as perforation of the root or the creation of ledges within the root canal, which can alter prognosis. If retrieval efforts are unsuccessful, cleaning and shaping procedures and obturation are compromised and the ultimate prognosis in placed in doubt.
Lighting and magnification equals vision and are critically essential for safe and successful instrument removal. The introduction of the dental operating microscope has certainly allowed clinicians good looks at the problems. Traditionally, small files were used in efforts to either bypass or eliminate the broken instrument. Varying diameter tubes have been advocated and are placed over the most coronal end of the obstruction and are utilized in a variety of ways to retrieve obstructions. Tubes are attached to the obstruction by glue, mechanical friction, or internal threads which engage certain broken instruments. The most recent advancement in broken instrument removal utilizes ultrasonic systems. Specific ultrasonic instruments have evolved and play a central role in removing broken instruments. Even with all the innovations directed towards safe and successful instrument retrieval a small but statistically significant number of broken instruments can not be retrieved with existing technologies and techniques. Therefore, the present invention provides a device that facilitates the removal of broken instruments and other intercanal obstructions from root canal systems.


A method and apparatus for sampling and converting analog input values. In response to an event, a value is transmitted from an input of a multiplexer to the output of the multiplexer. The output of the multiplexer is coupled to an input of an analog-to-digital converter (ADC). In response to a second event, a value is transmitted from the input of the multiplexer to a second ADC.

Modern control systems are growing in application and complexity. There are many classes of control systems, with many variations and combinations. Some control systems generate signals that control components of a device. For example, some automobile engine control systems generate signals that directly or indirectly control various components (e.g., spark plugs, fuel injectors, and the like) of an internal combustion engine. The present invention will be described with reference to an automobile engine control system, it being understood that the present invention should not be limited thereto.
The simplest engine control systems only control the timing and quantity of fuel injected into each cylinder during each cycle of the engine. More advanced engine control systems found in modern cars also control ignition timing, variable valve timing, the level of boost maintained by a turbo charger, etc. Using a complex set of algorithms, engine control systems can determine the quantity and timing of fuel injected into cylinders, ignition timing, and other needed parameters by monitoring the engine through sensors that include, for example, a manifold absolute pressure sensor, throttle position sensor, air temperature sensor, oxygen sensor, etc. In order to facilitate monitoring the sensors, the sensors' outputs should first be converted into digital values.

Transparent multiplexing of analog-to-digital converters


A method and apparatus for copying data from a virtual machine to a shared closure on demand. This process improves system efficiency by avoiding the copying of data in the large number of cases where the same virtual machine is the next to request access and use of the data. Load balancing and failure recovery are supported by copying the data to the shared closure when the data is requested by another virtual machine or recovering the data from the failed virtual machine and storing it in the shared closure before a terminated virtual machine is discarded.

1. Field of the Invention
The invention relates to virtual machine session data management. Specifically, the invention relates to copying data to a shared closure only on demand.
2. Background
In object oriented environments, such as the Java® platform by Sun Microsystems of Santa Clara, Calif., virtual machines are used to execute code for the platform. The virtual machines are executed by operating system processes and can be used to provide a server framework. The server framework may in turn provide a session manager and support a number of applications and similar services to clients. The state of each of the applications or application interfaces is referred to as a user session.
During the runtime of a platform a virtual machine may fail. As a result, user session data can be lost, causing loss of data and service for users. One common technique to protect against this loss is to store user session data in a persistent storage that is not affected by virtual machine failures. This technique is often referred to as 'session failover'. As a prerequisite for session failover, it must be possible to convert all objects that represent the user session into a form that may be stored in a persistent storage. Serialization is a feature of the Java® platform that allows objects to be transformed into a byte stream that may be stored in a persistent storage. Using this technique, all session objects are required to be serializable. A serializable object can be restored after session failover by the same virtual machine or another virtual machine. When a session manager determines that a session is to be persisted for storage in a persistent storage device, the complete user session is serialized and stored. However, this process involves a high performance cost. Converting and storing the objects of the session is a relatively slow process and diminishes overall system performance.
An alternative method of handling session failover utilizes shared closures. Shared closures provide an alternative mechanism for converting objects into a persistent form. In order to be usable with shared closures, session objects must be serializable and conform to additional restrictions to ensure that they can be transformed into their persistent state without having to execute user code. In this method a shared storage is utilized to allow multiple virtual machines to access the session objects and related data objects or 'shared closures.' A shared closure is an initial data object and transitive closure of all the objects that are references by this data object. These shared closures persist in shared memory even if a virtual machine fails. The session manager creates a shared closure for session objects instead of serializing them. Objects belonging to a session are traversed by the virtual machine code and copied to a shared memory block. This process is much faster than serialization.
However, session object data is still traversed and copied to the shared closure, which is only of benefit if the next request for the session is going to be processed in a different virtual machine. This traversal and copying occurs each time that something changes in the session data. In the case where the next request for the session data is from the same virtual machine, then the effort spent to copy the session data to the shared memory is wasted and the efficiency of the system reduced.


In accordance with the teachings of the present invention, a telescoping deployable mesh antenna reflector for space communication applications and a method of deployment is provided. The antenna reflector includes a plurality of telescoping radially extending ribs between which a plurality of interconnected guylines are secured to form a wire truss structure. The telescoping radially extending ribs include pivotally coupled inner and outer ribs that are collapsed and folded to stow the antenna. A highly reflective wire woven mesh is connected to the front surface of the wire truss structure with flexible radially extending strip members allowing for folding and telescoping of the antenna reflector.

1. Technical Field
This invention relates generally to compact antenna system structures and, more particularly, to a compact telescoping deployable antenna reflector structure.
2. Discussion of the Related Art
Antenna systems generally employ a reflector which serves as a ground plane to direct energy into a desired pattern. Antenna reflectors for space-related applications such as communication satellites are generally required to be relatively compact, lightweight, and capable of withstanding the exposure of a severe orbital environment. In addition to these design constraints, the reflector must meet stringent distortion requirements in order to attain desired performance requirements which are related to the aperture of the reflector.
Over the last several years, it has been a goal of the space industry to reduce the costs of both commercial and military satellite applications. One of the methods used to achieve this goal has been a shift from the use of large lift vehicles such as the Titan class vehicle or the Space Shuttle to medium launch vehicles such as the Atlas or Delta class vehicles. Because of space constraints accompanying this shift to smaller class vehicles, satellite antenna systems must be packaged more efficiently in order to retain the size of a given aperture so as to prevent experiencing a loss in performance.
Antenna systems have generally been provided which meet the design constraints for large lift vehicles to a limited extent and for a limited frequency range. Mesh materials have been employed to serve as a reflector's ground plane material, and deployment schemes have been provided for allowing a reflector to collapse within a relatively small space when not in use. However, the use of mesh materials requires precise surface settings to eliminate undesirable losses, and current mesh reflectors have not obtained the lowest possible losses. For example, the use of a wire mesh material in combination with current deployment schemes allows a reflector to fold to thereby stow and unfold to thereby be deployed. Unfortunately, by putting multiple folds into the reflector to reduce the stowed height of the antenna system, the stowed diameter of the antenna system is correspondingly increased.
It is therefore desirable to provide a compact deployable antenna reflector for use with medium launch vehicles having a reduced stowed height and diameter without reducing the reflector aperture and performance.
More particularly, it is desirable to provide a telescoping antenna reflector that telescopes and unfolds when deployed, is lightweight, exhibits low losses, and meets the design constraints required for space communication applications and the like.

Telescoping deployable antenna reflector and method of deployment