A cooling device is applied to cooling an electronic element producing concentrated heat in a case where the electronic element is housed in a portable electronic device such as a notebook PC. The cooling device is provided with an active heat transport element provided with a heat intake portion and a heat outlet portion, which conducts heat from the heat intake portion to the heat outlet portion, a first flow channel disposed upstream of the electronic element in flow of the cooling medium, a second flow channel disposed downstream of the electronic element in the flow of the cooling medium. The heat is by-passed by means of the active heat transport element so that the electronic element is exposed to flow of the cooled cooling medium and effectively cooled thereby.

1. Field of the Invention
The present invention relates to a cooling device for effectively cooling an electronic elements producing concentrated heat, such as a CPU, which is employed to a portable electronic device having few space to conduct and radiate the concentrated heat, such as a notebook PC, and a portable electronic device to which the cooling device is installed with an effective configuration.
2. Description of the Related Art
As technology has increased a capacity of electronic elements, it has been found that the amount of produced heat has increased significantly. Though the amount of the heat is in a range of several Watts to several tens Watts, it is far from easy to radiate the heat because the heat is generated in a concentrated manner, for example, it is generated at an area of 1 square centimeter or such. The problem of the concentrated heat comes to be more significant in a case of portable electronic devices, such as a notebook PC, because the portable electronic devices do not have enough space to equip a large cooling fan and a large heat sink.
As a device to effectively radiate the concentrated heat, there is proposed a heat radiation module having an air flow duct and a cooling fan housed therein, which covers a heat sink fixed to a CPU so as to flow relatively strong wind onto the heat sink. The heat radiation module effectively cools the CPU which is the most concentrated heat source in a notebook PC. However, if a heat value of CPU is increased, the heat sink and the cooling fan must be made larger and a rotation speed of the cooling fan must be higher. There is a definite limitation to provide a large heat sink and a large cooling fan with the notebook PC because the notebook PC is lack of a marginal space therein. Further, a severe noise generation caused by the high-speed cooling fan should be avoided because the notebook PC is usually used in a calm space.
Japanese Patent Applications Laid-Open No. 10-254583, No. 9-145273, No. 11-340671 and No. 8-42983 disclose cooling systems for a notebook PC, in which a heat pipe is employed. Japanese Patent Application Laid-Open No. 7-142886 discloses a cooling system for a notebook PC including a flexible tube and a pump for circulation of a liquid coolant.

Cooling device for electronic element producing concentrated heat and electronic device


The invention relates to novel artificial antigen presenting cells (aAPCs). The aAPC comprises at least one stimulatory ligand and at least one co-stimulatory ligand where the ligands each specifically bind with a cognate molecule on a T cell of interest, thereby mediating expansion of the T cell. The aAPC of the invention can further comprise additional molecules useful for expanding a T cell of interest. The aAPC of the invention can be used as an “off the shelf” APC that can be readily designed to expand a T cell of interest. Also, the aAPC of the invention can be used identify the stimulatory, co-stimulatory, and any other factors that mediate growth and expansion of a T cell of interest. Thus, the present invention provides powerful tools for development of novel therapeutics where activation and expansion of a T cell can provide a benefit.

Adoptive transfer is a term coined by Medawar (1954, Proc. Royal Soc. 143:58-80) to study allograft rejection. The term adoptive immunotherapy denotes the transfer of immunocompetent cells for the treatment of cancer or infectious diseases (June, C. H., ed., 2001, In: Cancer Chemotherapy and Biotherapy: Principles and Practice, Lippincott Williams & Wilkins, Baltimore; Vonderheide et al., 2003, Immun. Research 27:1-15). Adoptive therapy can be considered as a strategy aimed at replacing, repairing, or enhancing the biological function of a damaged tissue or system by means of autologous or allogeneic cells. The first successful infusion of ex vivo expanded, HIV infected, polyclonal CD4 T cells that enabled a high degree of engraftment upon infusion, was performed using magnetic beads coated with anti-CD3 and anti-CD28 beads (CD3/28 coated beads) to ex vivo expand the HIV infected individuals T cells. Eight patients were administered 51 infusions of costimulated CD4 cells under this protocol with minimal adverse advents (Levine et al., 2002, Nature Med. 8:47-53).
HIV infection induces a pronounced expansion of HIV-specific CD8 T cells. These CD8 T cells release soluble factors (Walker et al., 1986, Science 234:1563-1566; Zhang et al., 2002, Science 298:995-1000; Cocchi et al., 1995, Science 270:1811-1815) that limit HIV replication as well as directly lyse HIV infected cells (Walker et al., 1987, Nature 328:345-348; Koup et al., 1994, J. Virol. 68:4650-4655). Depletion of CD8 T cells prior to SIV challenge leads to unchecked viral replication and a rapid death, indicating that CD8 T cell activity is necessary to make HIV a chronic disease (Schmitz et al. 1999, Science 283:857-860; Jin et al., 1999, J. Exp. Med. 189:991-998). Yet, CD8 T cells ultimately fail to control HIV infection. HIV-specific T cells have been shown to have highly reduced perforin expression (Zhang et al., 2003, Blood 101:226-235; Appay, et al., 2000, J. Exp. Med. 192:63-75), down-regulation of two key signaling receptors, CD3ζ and CD28 (Trimble et al., 2000, Blood 96:1021-1029), a skewed maturation pattern (Appay et al., 2002, Nature Med. 8, 379-385) and a high sensitivity to Fas induced apoptosis (Mueller et al., 2001, Immunity, 15:871-882). Thus, it is believed that optimal activation of HIV specific CD8 T cells will restore effector functions.
Anti-CD3 and anti-CD28 (CD3/28) coated beads were the first generation of artificial APCs (aAPC) that permitted expansion of HIV-infected CD4 T cells (Levine et al., 1996, Science 272:1939-1943). In addition to delivering the signals needed for T cell activation and growth, CD3/28 bead stimulation renders T cells resistant to R5 infection by down-regulating CCR5 and up-regulating the expression of its ligands, the β-chemokines RANTES, Macrophage Inflammatory Protein-1 alpha (MIP-1α) and MIP-1β (Riley et al., 1997, J. Immunol. 158:5545-5553 Carroll et al., 1997, Science 276:273-276). Several phase I and II trials have demonstrated that infusion of autologous CD4 T cells expanded using CD3/28 coated beads into R5-infected individuals is both safe and feasible (Carroll et al., 1997, Science 276:273-276; Levine et al., 2002, Nature Med. 8:47-53; Walker et al., 2000, Blood 96:467-474; Ranga et al., 1998, Proc. Natl. Acad. Sci. U.S.A 95:1201-1206). More importantly, sustained increases in the total lymphocyte count, the CD4 to CD8 T cell ratio, the fraction of cytokine-secreting T cells, and the ability to respond to recall antigens were observed, suggesting that adoptive T cell immunotherapy can restore at least limited immune function back to HIV infected individuals (Levine et al., 2002, Nature Med. 8:47-53). Despite the success of these initial trials, several limitations were noted, including the difficulty of (1) expanding CD8 T cells, (2) adding additional costimulatory signals that may be required to expand certain subsets of T cells, (3) removing the beads before infusion and (4) generating antigen specific T cells with a high engraftment potential.
Others have used T cell expansion CD3/28 coated beads to introduce gene modified T cells to HIV infected patients. In these studies (Walker et al., 2000, Blood 96:467-474; Mitsuyasu et al., 2000, Blood 96:785-793; Deeks et al., 2002, Mol. Ther. 5:788-797), a chimeric molecule consisting of the extracellular domain of CD4 and the intracellular domain of the CD3 zeta chain (CD4ζ was introduced into CD4 T cells via retroviral transduction). CD4ζ-modified T cells were detected by DNA PCR in the peripheral blood of all patients following infusion, and mean levels of 1-3% of total peripheral blood mononuclear cells (PBMCs) were sustained at all post-infusion time points. In an extended follow-up, CD4ζ was detected in the blood of 17 of 18 patients one year following infusion. These levels of sustained engraftment are several orders of magnitude higher than what has been previously observed for human T cell infusions, perhaps because previous cell culture techniques may have induced susceptibility to apoptosis or replicative senescence (Rosenberg et al., 1990, N. Engl. J. Med. 323:570-578; Yee et al., 2002, Proc. Natl. Acad. Sci. U.S.A. 99:16168-16173; Brodie et al., 1999, Nature Med. 5:34-41; Riddell et al., 1996, Nature Med. 2:216-223; Riddell et al., 2000, Cancer Journal 6:S250-S258). These clinical results indicate that costimulated T cells propagated with bead-based aAPCs are safe and have the capacity for prolonged engraftment. However, due to the limited number of study subjects and length of time required to achieve a clinical endpoint in a HIV therapeutic trial, statistical significance of the clinical benefit of autologous CD4 T cell transfer to HIV infected individuals could not be measured.
While potentially effective in limiting immunodeficiency, polyclonal CD4 T cells are likely to have only a modest effect on the HIV specific response. Immunotherapy of human viral infection using adoptive transfer of antigen-specific CD8 T cells has been studied in the setting of CMV, EBV, and HIV infection. This approach has been evaluated using T cell clones with HLA-restricted antigenic specificity for CMV (Riddell et al., 1992, Science 257:238-241; Walter et al., 1995, N. Engl. J. Med. 333:1038-1044). CMV-specific CD8+ T cells isolated from MHC-identical bone marrow donors were expanded ex vivo and were administered to 14 allogeneic bone marrow transplant recipients. Recovery of CMV-specific CTL activity was seen in each case and adoptively transferred CTL persisted in vivo for up to 12 weeks. In a similar study, donor-derived EBV-specific CD8+ and CD4+ T cells, genetically marked with the neomycin resistance gene, were administered to 6 recipients of T cell-depleted allogeneic bone marrow allografts (Rooney et al., 1995, Lancet 345:9-13; Heslop et al., 1996, Nature Med. 2:551-555). Gene-marked CD4+ and CD8+ T cells responsive to in vivo or ex vivo challenge with EBV persisted at low frequencies in vivo for as long as 18 months after infusion. Infusion of CD8 T cells with a single specificity to HIV (Nef) (Koenig et al., 1995, Nature Med. 1:330-336) into one patient demonstrated CTL selection of viral variants indicating that infusion of HIV specific T cells against multiple targets may be necessary to control HIV replication. In all of these studies, the inability of the vast majority of these T cells to engraft has limited the study of the long-term effects of antigen specific CD8 T cell immunotherapy. A major challenge in the field is to expand CD8 T cells that will engraft and have potent effector functions on a long-term basis to more effectively fight chronic infections. However, despite the long-term need for sufficient numbers of therapeutic T cells, there are no methods available for expanding these cells.
HIV specific T cells are able to contain but not eradicate HIV. Studies that have removed CD8 T cells prior to, or during, HIV infection have demonstrated unchecked viral replication and a much faster progression to AIDS, indicating that CD8 T cells are important in controlling HIV (Schmitz et al. 1999, Science 283:857-860; Jin et al., 1999, J. Exp. Med. 189:991-998). However, HIV specific T cells in general, lack perforin expression (Gandhi et al., 2002, Annu. Rev. Med. 53:149-172) and other requisite effector functions to eliminate HIV from the host. Studies of long term non-progressors indicated that HIV specific T cells from these individuals are more likely to proliferate and contain perforin, demonstrating that CD8 T cells with enhanced effector functions may delay the progression to AIDS (Migueles et al., 2002, Nature Immunol. 3:1061-1068). Other investigators have demonstrated that two key signaling receptors, CD3ζ and CD28 are downregulated on HIV specific T cells (Trimble et al., 2000, Blood 96:1021-1029; Trimble et al., 1998, Blood 91:585-594; Trimble et al., 2000, J. Virol. 74:7320-7330), and that HIV-specific T cells are more sensitive to Fas induced apoptosis (Mueller et al., 2001, Immunity, 15:871-882). Appay et al. (2002, Nature Med. 8:379-385) examined the differences between HIV-, EBV-, and CMV-specific CD8 T cells based on CD27 and CD28 expression. Early differentiated T cells expressed both CD27 and CD28 and possessed poor effector functions but excellent proliferative abilities. Intermediate T cells were CD27 positive but CD28 negative, and these cells had limited proliferative and effector functions. The most differentiated T cells lack both CD27 and CD28, and these cells had little proliferative ability but enhanced effector functions. It was observed that most of the HIV-specific T cells had the intermediate phenotype. Therefore, the cells being "stuck" in this intermediate T cell phenotype that lack both proliferative capacity and effector functions may be the contributing factor to the ineffectiveness of HIV-specific T cells (Appay et al., 2002, Nature Med. 8, 379-385). Moreover, CD8 T cell function is highly dependent upon CD4 T cell function (Zajac et al., 1998, J. Exp. Med. 188:2205-2213; Shedlock et al., 2003, Science 300:337-339; Sun et al., 2003, Science 300:339-342) and since HIV targets CD4 T cells, the CD8 T cell defects observed in HIV infection could be the result of a lack of T cell help.
Thus, there exists a long-felt need to provide ways to stimulate T cells to combat various acute and chronic diseases and to promulgate sufficient numbers of therapeutic T cells for adoptive immunotherapy. The present invention meets this and other needs.

Artificial antigen presenting cells and uses thereof

The Trustees of the University of Pennsylvania


The combination of a fluid operated cleaner, to be directed into a conduit to remove obstructions in a passageway defined by the conduit, and a manipulator. The conduit cleaner has a frame which has a connector for a fluid supply conduit. The manipulator is connected to the conduit so that the manipulator and fluid supply conduit can be used together to reposition the conduit cleaner at a location remote therefrom. Between the manipulator and the fluid supply line, the user is given substantial flexibility in reorienting the conduit cleaner to allow it to be introduced to the entryway of a remotely located conduit.

1. Field of the Invention
This invention relates to conduit cleaners, such as those used to grind/break up foreign matter within, or flush the surface of, a conduit and, more particularly, to a manipulator for the conduit cleaner that facilitates direction of the conduit cleaner into the entryway of a conduit remote from the user thereof.
2. Background Art
Conduit cleaners are well known in the art. In U.S. Pat. No. 3,740,785, to Latall, one such unit is described in detail. This unit has been very commercially successful.
Briefly, the Latall unit has a motor that is operable through a pressurized fluid. Fluid under pressure is directed to the motor to effect operation thereof and to a plurality of jets which cause discharge of the fluid in a trailing direction, which both affords propulsion to the unit and scours the inside of a conduit passageway. The motor drives a rotary blade at the front of the unit which grinds foreign matter within the conduit. A skid assembly facilitates guided movement of the unit within a conduit.
These units are typically used to route sewer lines. In one typical application, a large, vertically extending sewer shaft communicates with a horizontally extending conduit. The sewer shaft may be accessible through a ground level entryway that is closed by a man hole cover, with the entryway to the horizontally extending conduit being many feet below the main sewer opening. Typically, a unit, such as that in U.S. Pat. No. 3,740,785, must be directed through the horizontal conduit. Since the horizontal conduit is not within the reach of a user above ground through the main sewer opening, several different techniques have been employed in the past to introduce the conduit cleaner to the horizontal conduit.
In a first method, the user effects the introduction solely by manipulating a fluid supply conduit that is operatively connected to the conduit cleaner. The supply line is normally flexible but has sufficient rigidity to allow the user to effect reorientation of the conduit cleaner. Typically, the user will blindly lower the conduit cleaner through the supply line into the sewer opening into alignment with the entryway for the horizontal conduit by feeding an amount of the supply conduit out roughly corresponding to the depth of the horizontal conduit. After proper alignment is achieved, the user swings the supply line back and forth in hopes that the conduit cleaner will find its way into the horizontal conduit entryway. Since the entryway to the horizontal conduit is normally not visible from overhead, this operation usually involves trial and error.
Alternatively, the user may be required to feel out the entryway by dragging the conduit cleaner up and down against the wall of the sewer shaft. Both of the above procedures are often frustrating and time consuming endeavors.
One alternative method of introducing the conduit cleaner to the horizontal conduit requires that the user physically move down the sewer shaft into close proximity to the horizontal entryway. In this position, the user can positively feed the conduit cleaner into the horizontal conduit. While this procedure is the most reliable known to date, once the user is required to actually enter the sewer opening, the element of danger is introduced. The user is prone to injury unless the procedure is carefully and properly carried out.
In spite of the drawbacks with the prior art equipment and procedures to date, no alternative exists to those described above for introducing a conduit cleaner into a horizontal conduit remote from a user.


A vacuum cleaner with a main body, an upper body and a lower body. The upper body, in which a motor and dust collector are installed, is joined to the lower body, which supports the upper body and also allows the rotation of the upper body. Coupling means joins the upper body to the lower body so as to allow the upper body to rotate on the lower body. One of the coupling means is fixed on the upper body's bottom center, and the other end is a shaft that is joined to the lower body's top center. A bearing member is installed between the upper body's bottom and the lower body's top surface so as to reduce frictional resistance between the two components. The bearing member includes grooves formed on the top surface of the lower body, and balls seated in the grooves that move freely therein, thereby preventing damage to a connecting hose connecting the cleaner's cleaning attachment with the main body.

(1) Field of the Invention
The present invention generally relates to a vacuum cleaner. More particularly, it relates to the main body of a vacuum cleaner which produces a vacuum to draw up dust and loose dirt from rugs and other surfaces.
(2) Description of the Prior Art
A conventional vacuum cleaner is used to clean floors and floor coverings by drawing up the dirt from them in air. It does this by using a vacuum created by the difference between the internal pressure of the cleaner's main body and the atmospheric pressure. FIG. 3 illustrates the overall construction of a conventional vacuum cleaner. It is comprised of a main body 10 equipped with a driving means (not illustrated) and a dust collecting means (not illustrated), a cleaning attachment 30 through which dirt and dust are drawn from surfaces to be cleaned by the vacuum generated in the main body 10, and an extension pipe 20 and a connecting hose 22 that connect the cleaning attachment 30 with the main body 10. The ends of the connecting hose 22 are respectively attached to the main body 10 and one end of the connecting joint 21, on which a handle 23 is formed. The other end of the connecting joint 21 is connected to the extension pipe 20, which is also fitted with the cleaning attachment 30, so that the extension pipe 20 may communicate with the connecting hose 22. Reference numeral 24 denotes a control portion.
The main body 10 produces a vacuum by the operation of a motor (not illustrated), the driving means, and includes a dust collecting bag that serves as the dust collecting means (not illustrated). The main body 10 also includes front and rear wheels 11 and 12 on its bottom for facilitating its movement.
The connecting joint 21 and the connecting hose 22, which are made of a flexible material, are passages through which dust and dirt are drawn into the main body of the vacuum cleaner. The cleaning attachment 30 includes a suction hole 31 that communicates with the extension pipe 20 through the cleaning attachment's 30 suction path 32, through which the dirt from a surface to be cleaned is drawn into the main body 10 along with air. Reference numeral 33 denotes a roller that allows the cleaning attachment 30 to move more easily.
Once a user turns on the conventional vacuum cleaner by using the control portion 24, the motor (not illustrated) of the main body 10 goes into action to create a vacuum. Thus, as the air is drawn into the main body 10 at high speeds sequentially through the cleaning attachment 30, the extension pipe 20, the connecting joint 21, and the connecting hose 22, the dirt and dust on surfaces to be cleaned are drawn into the main body 10's dust collecting bag (not illustrated) by way of the suction hole 31 and the suction path 32. That is, the dirt is inhaled through the cleaning attachment 30 by the vacuum created in the main body 10, and is finally collected in the main body 10 through the extension pipe 20 and the connecting hose 22.
Since the user cleans floors and floor coverings with this conventional vacuum cleaner, the user must move the cleaning attachment 30 over a large surface. Consequently, the main body 10 also moves about the floor. Though the front and rear wheels 11 and 12 accommodate frontwards and rearwards motion and allow the main body 10 to move smoothly in those directions, they can not provide for the smooth left or right rotation of the main body 10. Instead, the rotational force is applied to the end of the connecting hose 22 that is connected with the main body 10, thereby causing damage to the connecting hose 22. These factors pose an inconvenience to the user and a decrease of the vacuum cleaners's cleaning efficiency.


Provided is a printing apparatus including: a photosensitive drum; a substrate including multiple formable regions in each of which corresponding one of multiple light emitting elements is formable; and a lens array, in which the substrate is arranged in a manner that a longitudinal direction of the substrate is parallel to a rotary shaft of the photosensitive drum, in which the substrate includes m formable region rows, where m is an integer number equal to or greater than 2, each of the m formable region rows including n formable regions, where n is an integer number equal to or greater than 1, arranged in a line along the longitudinal direction of the substrate, and in which one of the multiple light emitting elements formed in any one of m formable regions that are located in a predetermined column of the m formable region rows is turned on.

1. Field of the Invention
The present invention relates to a printing apparatus, and more particularly, to a printing apparatus that is used in an electrophotographic system such as a copying machine and a printer, and includes an optical head having a light emitting element array.
2. Description of the Related Art
As an example of printing apparatus employing an electrophotographic system, there is given a printing apparatus including an exposure head including a light source which has an array of light emitting elements such as light emitting diodes. When the light source having the array of light emitting elements is used in the exposure head, the exposure head itself is downsized. Thus, quietness of the printing apparatus can be easily achieved. As an example of using the light emitting elements such as light emitting diodes as the light source of the exposure head as a component of the printing apparatus, there is given a light emitting element array disclosed in Japanese Patent Application Laid-Open No. H10-55890. The light emitting element array disclosed in Japanese Patent Application Laid-Open No. H10-55890 is manufactured by forming multiple organic EL elements collectively on an insulating substrate such as a glass substrate. Further, in Japanese Patent Application Laid-Open No. H10-55890, light beams output from the light emitting element array are converged with a converging rod lens array. The converged light beams are radiated onto a photosensitive drum so as to form a predetermined image.
However, the single-row light emitting element array disclosed in Japanese Patent Application Laid-Open No. H10-55890 has a problem in that the light emitting element array as a whole is treated as a defective product in a case where any single one of the light emitting elements of the array becomes defective. This is because, when printing is performed with the light emitting element array including the defective element, the defective element causes streak-like image defects on a printed material. The streak-like image defects are significantly conspicuous on the printed material, which are quite unacceptable to users. However, when a defect of even single one of the light emitting elements of the array cannot be accepted, there are problems of a decrease in manufacture yield and an increase in manufacturing cost of the light emitting element array.
As solutions to the above-mentioned problems, there have been proposed a method disclosed in Japanese Patent Application Laid-Open No. 2009-154420, and a method disclosed in Japanese Patent Application Laid-Open No. 2008-65200. In the configuration proposed in Japanese Patent Application Laid-Open No. 2009-154420, light emitting elements in multiple rows are provided to a single line head. When the light emitting elements of the line head are switched in row units, operation can be performed without using rows including defective elements. With this, a high yield can be achieved. Further, in the method proposed in Japanese Patent Application Laid-Open No. 2008-65200, a light emitting portion of a single light emitting element is split into multiple sub light emitting portions. Specifically, in the method proposed in Japanese Patent Application Laid-Open No. 2008-65200, when one of the multiple sub light emitting portions becomes defective, only the defective part is disconnected from a pixel drive circuit. With this, electric current from the pixel drive circuit can be applied only to normal sub light emitting portions. Thus, the light emitting elements each can emit light with desired light intensity.
However, in the light emitting elements in multiple rows of Japanese Patent Application Laid-Open No. 2009-154420, when even single one of the light emitting elements in one row becomes defective, the row including the defective light emitting element is treated as a defective part. This state has no difference from the case of the light emitting element array of Japanese Patent Application Laid-Open No. H10-55890. Thus, when even single one of the light emitting elements in each column becomes defective in all the rows of the light emitting elements of the line head, the rows including the defective light emitting elements are each treated as a defective part. As a result, the line head itself is treated as a defective product. In particular, when even some of the rows of the light emitting elements have a high defect rate, a yield of the line head itself may be insufficient.
Meanwhile, in the method proposed in Japanese Patent Application Laid-Open No. 2008-65200, print image quality may not be maintained as described below. For example, in a case where a single pixel is split into two sub light emitting portions (portion A and portion B) in the method proposed in Japanese Patent Application Laid-Open No. 2008-65200, when the pixel is normal, both the two sub light emitting portions (portion A and portion B) emit light. However, when any of the two sub light emitting portions becomes defective, only non-defective one emits light (only the portion B when the portion A is defective). In this case, in a pixel having such a defective sub light emitting portion, electric current from the pixel drive circuit is applied only to the non-defective sub light emitting portion, and the non-defective sub light emitting portion emits strong light. Also with this, required total light intensity may be cooperatively achieved by all the pixels. However, light emitting areas of the pixels vary from each other depending on whether or not a defect has occurred, and hence unexpected unevenness in color tone appears on a printed material. As a result, there arises a problem of difficulty in maintaining print image quality.


The invention relates to a solenoid valve made using certain materials which is capable of operation at high frequencies and which can be made as a compact unit. The plunger (1) is made from an electromagnetic material having a saturation flux density greater than 1.2 Tesla preferably more than 1.6 Tesla, the bore leading from the valve head chamber (14) to the nozzle orifice (12) has a length to diameter ratio of less than 5:1 preferably between 2:1 and 4:1 and the nozzle orifice (12) has a diameter of 80 micrometer or less. The invention also relates to method for operating a drop on demand ink jet printer incorporating such a valve.

Ink jet printers are non-contact printers in which droplets of ink are ejected from one or more nozzle orifices so as progressively to build up a printed image on a substrate moved relative to the nozzle. One form of ink jet printer comprises a source of ink, typically a reservoir or bottle of ink, which is pressurised to from 0.1 to 2 bar, notably about 1 bar. The pressure is created, for example, by pressurising the air space above the ink in the bottle or reservoir. The ink is fed to the nozzle orifice(s) in a print head through which it is ejected as a series of droplets onto the surface of the substrate. The flow of ink through each nozzle orifice is controlled by a solenoid valve. Typically, such a valve comprises an electromagnetic plunger journalled for axial movement within an axially extending electric coil. The distal end of the plunger is located within a valve head chamber through which ink flows from the reservoir to the nozzle orifice. When current is fed through the coil, this generates a magnetic field which acts on the plunger to move it axially and thus open, or shut, the inlet of a bore from the valve head chamber to the nozzle orifice. Typically, the magnetic field acts to retract the plunger against the bias of a coil spring to create a flow path between the valve head chamber and the nozzle orifice. When the electric current no longer flows in the coil, the magnetic field ceases and the plunger returns under the bias of the spring to close the flow path to the nozzle orifice. Typically, a plurality of nozzle orifices are formed as one or more rows in a plate, the nozzle plate, and each nozzle orifice is served by a separate solenoid valve, so that droplets of ink can be ejected independently from one or more of the nozzle orifices. Typically, the valves are fed with ink from the reservoir via a manifold which serves to split and even the ink flow between each of the valves. The row of nozzle orifices is typically aligned transversely to the direction of travel of the substrate so that simultaneous operation of the valves will cause a row of ink dots to be printed on the substrate.
The valves are operated so as to deposit dots upon the substrate at the desired locations on the substrate to build up the elements of a five, seven, eight or more dot raster image on the substrate. By suitable timing of the opening of the various valves in the print head an alphanumeric or other image can be formed on the substrate to print a date, product batch code, logo, bar code or other image on the substrate. If desired, several print heads can be combined in an array so as to print a wider image on the substrate and the line of nozzle orifices in the print head can be angled to the direction of movement of the substrate so as to lay down droplets which are more closely spaced than where the print head is aligned normal to the line of travel of the substrate.
For convenience, the term drop on demand printer will be used to denote in general such types of ink jet printer.
The size of the printed dot can readily be altered by varying the duration for which the valve is held open, and hence the amount of ink that it allows to flow through the nozzle orifice. The form of the image which is printed can readily be altered by varying the sequence of operation of the valves in the print head so that droplets are ejected from the appropriate nozzles in the appropriate sequence to form the desired image. Such alterations of the images and the dot sizes can readily be controlled by a computer or microprocessor operating under an appropriate program or operating system. Such drop on demand printers are widely available commercially and find widespread use in printing a wide range of both visible and non-visible machine-readable images on a wide range of substrates.
However, as the speed of travel of the substrate past the print head increases, a point is reached at which the valve cannot be operated at sufficient speed to eject droplets at sufficient frequency to form the desired image without creating some distortion. Typically, the limit for the speed of operation of solenoid valves in current use in an ink jet printer head is less that 800 to 1000 Hz. With increasing pressure on manufacturers to increase through put from a given production or packaging line, there is an increasing need to be able to print the dots onto the substrate at rates greater than this.
In an alternative form of ink jet printer known as an impulse jet printer, a piezoelectric crystal or other transducer is applied to or forms part of a wall of an ink jet chamber having an ink inlet and an ink outlet to a nozzle orifice. When a voltage is applied to the transducer, the transducer expands or flexes and causes a change in the volume of the ink jet chamber. This causes a droplet of ink to be ejected from the chamber and to exit through the nozzle orifice. The transducer can be caused to flex at very high rates by electronic control of the frequency of the electrical pulses applied to the transducer, so that such a print head can apply dots at frequencies up to 15 kHz or more. However, the volume of ink ejected through the nozzle orifice is dependent upon the extent of flexing of the transducer. This can be varied by varying the amplitude of the electric pulse applied to the transducer. However, each type of transducer operates consistently only within a narrow percentage, typically plus or minus 50%, of the optimum operating pulse amplitude, so that only a limited range of dot sizes can be achieved with a commercially available impulse jet printer. This limits the number of applications for which a given impulse jet head can be used for.
It has been proposed in International Patent Application No PCT/SE97/01007 to produce a solenoid type valve for a drop on demand ink jet printer which is claimed to be capable of operating at frequencies of up to 3 kHz. Such a valve incorporates light weight components so as to reduce the inertia of the plunger and thus enable it to accelerate and decelerate rapidly at each extreme of its travel within the coil. To achieve this, the plunger is formed from two components, one made from an electromagnetic material so that it can be caused to move by the magnetic field generated by the current passing through the coil, and a second lightweight plastic component for the distal end of the plunger. Such a construction is complex and expensive. Furthermore, we have found that a print head incorporating such a valve design does not print acceptable images. For example, at high frequencies of operation of the valve, the printed dots are uneven and there are many small satellite dots around each of the primary dots printed by the print head.
We have now devised a form of valve which can be operated at speeds of up to 8 kHz or more and yet can be used in a drop on demand printer to print uniformly sized droplets over a surprisingly wide range of dot sizes and operating frequencies. Furthermore, the valve of the invention can be more compact and with smaller components than a conventional design of solenoid valve for use in a drop on demand ink jet printer. This allows high definition printing to be achieved at high print rates without excessive heat being generated during operation of the valve. Such a valve enables drop on demand technology to be used in high speed applications for which an impulse jet print head had hitherto been considered the only technically viable form of print head.

This patent is subject to a terminal disclaimer.


Communication devices, communication systems, a Bluetooth communication protocol communication device, and communication methods are provided. According to a first aspect, a communication device includes a single buffer configured to store communication data; control circuitry coupled with the buffer and configured to generate a plurality of packets including different amounts of communication data from the buffer; and communication circuitry coupled with the control circuitry and configured to communicate the packets.

Conventional cordless telephone configurations include a handset coupled via radio connection with a base station. The base station is usually connected by wire to a traditional Public Switched Telephone Network (PSTN) or an Integrated Services Digital Network (ISDN). The development of new cordless standards which are based upon digital technology provides a broad spectrum of applications. Exemplary cordless applications include wireless Private Automatic Branch Exchange (PABX), wireless Local Area Network (LAN), Telepoint, and Radio Local Loop. Cordless standards include for example Digital Enhanced Cordless Telecommunications (DECT), Bluetooth, GSM, PHS, AMPS, IS54 or IS95. The digital cordless telephones represent a valid alternative to cellular phones in densely populated areas.
DECT is a cordless standard defined as a Multicarrier (MC), Time Division Multiple Access (TDMA)/Time Duplex Division (TDD) system. Time is divided in the DECT standard into frames of 10 ms. Each frame is divided into 24 full slots. The standard also allows for half slots and double slots of data.
In order to be able to support multiple channels, a DECT base station compresses and transmits 10 ms of speech during one full slot. This means that 10 ms of speech are actually sent over the radio in 416 μs. Every active connection makes use of two slots, one for receiving and one for transmitting. For example, if the slots in a DECT frame are numbered from 0 to 23, the first 12 slots (0-11) are used for transmission from the base station to the handset and the remaining slots are used for handset to base station transmission. A base station transmitting to a given handset in slot N receives from this handset in slot N plus 12, or in other words, half a frame later. Accordingly, a DECT base station is able to support up to 12 active voice connections at the same time.
The total number of bits within a conventional DECT slot is 480. With 24 slots and a 10 ms frame, a gross bit rate of 1.152 Mbits/s is provided. Once the DECT slot has been formatted, it is transmitted using one of 10 radio frequencies specified within the DECT standard. For example, the frequency band assigned to DECT in Europe is between 1,880 and 1,900 MHz, with a spacing of 1.728 kHz between adjacent frequencies. The transmission frequency for each channel is chosen dynamically based upon a Radio Signal Strength Indication (RSSI). Each active slot in the DECT frame may be transmitted and received on any of the 10 frequencies.
In exemplary communication systems, a first communication unit transmits voice samples to its counterpart unit. The TDMA structure is utilized to transmit and receive packets via a radio frequency (RF) channel to implement the exchange of voice samples between the two units. In typical digital communication systems, voice data is typically provided in an 8 kHz sample stream.
In a conventional DECT system, voice is typically carried over a fixed length packet using a single packet length cyclical speech buffer. Such service in DECT is called In_minimum_delay. Such guarantees that every slot in the TDMA structure carries the latest voice data. For this service, offsets within the speech buffer are used to address the latest speech samples to be used by the packet in the TDMA slot. If the voice is transmitted over two packets (e.g. in a handover case) both packets using different slots can use the same speech buffer but with different offsets. In DECT communications, there is no need for an additional buffer when switching form one slot (packet) to another slot (packet).
Referring to FIG. 1, an example of In_minimum_delay handover communications in a DECT system is illustrated. For example, during a handover between two slots (e.g. slot 0 and slot 4), voice data is utilized from a common buffer. However, the data communicated in each slot is different. For example, at the fixed part (FP) ADPCM data samples 0 to 39 are communicated to the portable part (PP) or handset in slot 0 (wherein offset is equal to zero). At the portable part, this data is forwarded to the ADPCM components starting with data 0 (wherein offset is equal to zero). At the time slot 4, the latest data arrives and is sent from the fixed part to the portable part in slot 4. Slot 4 includes data samples 6 to 39 (offset equals 6) which have also been sent in the previous slot 0 and the new ADPCM data 0-5 which arrived during the time between slot 0 and 4. At the portable part, slot 4 (offset equals six) will overwrite the data 6-39 received from slot 0. However, since this is the same ADPCM data there is no difference at the portable part ADPCM side for continuity. At the portable part, ADPCM data from slot 0 and slot 4 will be used depending on which slot has been received last. DECT In_minimum_delay allows voice data to be communicated between a fixed part and portable part irrespective of slot number.
The Bluetooth communication protocol standardizes data synchronization between disparate devices. The aim of Bluetooth communication protocol is to provide a single digital wireless protocol to address end-user problems arising from the proliferation of various mobile devices such as Smart Phones, Smart Pagers, hand held PCs, and Notebooks where it is desired to keep data consistent from one device to another.
According to the Bluetooth communication protocol or standard, it is described that voice packets, with different numbers of speech samples, can be used to transmit voice information. Depending on the number of speech samples in a packet, packets are spaced differently. Such permits selection between voice quality and amount of channel bandwidth used. A voice packet can be switched from one type to another type to permit dynamic selection between quality and bandwidth.
For example, if there are no desired bandwidth limitations, a high quality voice packet (HV1) with a minimum number of speech samples and a high number of added forward error correction (FEC) bits is used. However, when additional bandwidth is needed for other purposes (e.g. a second communication channel), a high quality voice packet is switched to a packet with a lower quality (HV2) and lower bandwidth requirements communicating a higher number of speech samples but a lower number of FEC bits.
Referring to FIG. 2, conventional voice packet switching according to the Bluetooth communication protocol is illustrated. Graph 2 corresponds to accessing data with respect to a high portion and a low portion of a first transmit buffer shown in FIG. 3. Data is written to the buffer from a data side and accessed from the buffer from a packet side in graph 2.
Graph 3 corresponds to accessing data with respect to a high portion and a low portion of a first receive buffer shown in FIG. 3. Data is read from the buffer from a data side and written to the buffer from a packet side 11 in graph 3.
Graph 4 corresponds to accessing data with respect to a high portion and a low portion of a second transmit buffer shown in FIG. 3. Data is written to the buffer from the port side and read from the buffer to a packet side in graph 4.
Graph 5 corresponds to accessing data with respect to a high portion and a low portion of a second receive buffer shown in FIG. 3. Data is written to the buffer from the packet side and read from the buffer to a port side in graph 5.
Graph 6 represents a TDMA frame structure comprising a plurality of TDD frames for the conventional operations.
Graph 7 represents transmit packets and graph 8 represents receive packets within a Bluetooth device. HV1 packets represent a minimum number of speech samples and a spacing of two slots for TDD frames −2, −1, 0.
For TDD frames 1-4, HV2 packets including a higher number of speech samples and a spacing of four slots are communicated. Such permits available bandwidth for other communications during TDD frames 2 and 4 as shown.
According to the Bluetooth communication protocol, three voice packets are defined using different repetition intervals. For packets HV1, TSCO (the repetition interval between packets) is equal to two and a new packet is started every two slots permitting one communication link. For HV2 packets, TSCO is equal to four wherein a new packet is started every fourth slot providing two communication links. For HV3 packets, TSCO is equal to six wherein a new packet is started every sixth slot providing three possible communication links.
Referring to FIG. 3, the exemplary Bluetooth buffer system is depicted. Two buffers configurations 9, 10 including respective buffer pairs 11, 12 are coupled with a packet composer 15 of an exemplary Bluetooth buffer system. Individual ones of buffers 11, 12 include respective buffer portions 13, 14. Buffer configuration 9 and buffer configuration 10 are coupled in parallel with packet composer 15 and synchronous I/O ports as shown. Conventional operations in FIG. 3 are described herein with reference to transmit operations.
Buffer configuration 9 corresponds to higher quality (HV1) communications while configuration 10 corresponds to lesser quality (HV2) communications. Buffer configuration 9 includes plural discrete buffers 11 individually having a size to hold a given number of data samples to be communicated in an HV1 packet. Buffer configuration 10 corresponds to lower quality communications and includes plural discrete buffers 12 individually having a size to hold more data samples than the number of data samples of buffers 11.
The buffers 11, 12 of respective configurations 9, 10 are used to communicate packets and switching between configurations 9, 10 is utilized to communicate packets having different numbers of data samples. During switching operations intermediate higher quality communications (HV1, and lower quality communications (HV2) buffers 11 and buffers 13 can not be properly aligned and accordingly errors result. Such interrupts speech data and is noticeable to a user.
Speech typically requires a synchronous continuous data channel. Any interruption in the speech data stream will be noticeable by the user in the form of clicks, missing speech, speech deformation, etc. Switching between different buffer configurations to communicate voice packets having different numbers of speech samples introduce interruptions in speech communications resulting in noticeable errors during the communications.

Apparatus and method for extraction of different types of packets from respective portions of a single buffer


An exchangeable condenser system for a phase-contrast illuminating system (12) for microscopes has a plurality of different light rings (5), arranged on a nosepiece plate (4), assigned to the condenser optical system (6). The condenser optical system (6) can be exchanged independently of the light rings (5), the focal lengths F.sub.n of the exchangeable condenser optical systems (6) being selected relative to one another in the ratio F.sub.n =F.sub.0 *X.sup.n and the average diameters D.sub.n of the light rings (5) being selected relative to one another in the ratio D.sub.n =D.sub.0 *X.sup.n, where X>0, n=0,1,2,3, . . . .

The invention relates to a condenser system for a phase-contrast illumination system for microscopes and to a condenser system for a fringe-contrast illumination system for microscopes.
In condenser systems for a phase-contrast illumination system in microscopes, it is known to use different condensers with a set of light rings specially adapted to each individual condenser. A set of light rings contains individual light rings having different light ring diameters. In microscopes having various objectives of differing magnifying power, it is usually necessary to make available a plurality of different light rings having different diameters per condenser. It has previously been necessary for this combination of condenser and set of light rings to be arranged in a mechanically expensive way in the illuminating beam path. The arrangement of the set of light rings with the associated condenser optical system in the illuminating beam path was made in a known embodiment such that the set of light rings was arranged together with the condenser optical system in a separate nosepiece. The entire nosepiecc was exchanged when changing the condenser optical system. However, this required the exchanging guides of the nosepiece and the guides on the microscope to be precisely manufactured, and in addition required adjusting elements for centering the condenser to be made available. In addition to the substantial manufacturing outlay for such exchangeable nosepieces, it is also disadvantageous in this known solution that a special set of light rings in a special nosepiece must be made available for each condenser optical system.
DE 23 37 653, which corresponds to U.S. Pat. No. 3,790,254, discloses a condenser system for phase-contrast illumination system in microscopes, in which a plurality of condensers having the same focal length and different free working distances are represented and described. Owing to this special row of condensers, a single set of light rings can be used for different condensers.
However, in practice the row of condensers described can be used only to a limited extent, since it is possible to realize optically only a free working distance amounting to a maximum of 5.5 mm. At larger distances, up to 70 mm, such as are urgently required in inverted microscopes for viewing objects in petri dishes, microtitration plates, culture flasks and the like, optical reasons preclude the realization of a constant focal length of the different condenser optical systems.
In known condenser systems for a fringe-contrast illumination system with microscopes, there is likewise the problem that the very expensive Wollaston prisms have to be adapted to the objectives employed, which have different magnifying powers, and to condenser optical systems. There is a need here, as well, for a plurality of specially built prisms for each condenser optical system which are likewise arranged in a nosepiece plate upstream of the condenser. The use of the prisms depends in this case on the respective magnifying powers and focal lengths of the objectives and condenser optical systems.


Systems and methods for diagnosing operation of a catalyst are presented. In one example, threshold limits for catalyst variables are adjusted in response to attributes of a catalyst monitor sensor that may vary with sensor age. The catalyst variables may provide insight into whether or not the catalyst is degraded or operating as intended.

Vehicles may include a catalyst for processing engine emissions. Performance of a catalyst may degrade over time due to the catalyst being exposed to elevated temperatures, mechanical vibration, sulfur contamination, and exposure to other operating conditions that may be encountered during a course of operation. If a catalyst degrades by more than a desired amount, vehicle tailpipe emissions may be elevated to an undesirable level. Thus, it may be desirable to provide a robust way of judging if a catalyst is performing as desired.
One way of diagnosing operation of a catalyst is to use oxygen sensor information. In particular, oxygen sensors may be placed in an exhaust system upstream and downstream of a catalyst. Information from the upstream and downstream oxygen sensors may be a basis for judging whether or not a catalyst is performing in a desired way. However, oxygen sensor performance may degrade over time. Output of a degraded oxygen sensor may lead to judging that a poor performing catalyst is performing in a desired manner. Therefore, it may be desirable to provide a way of separating oxygen sensor performance from catalyst performance when judging if a catalyst is operating as desired.
The inventors herein have recognized the above-mentioned disadvantages and have developed a method for diagnosing a catalyst, comprising: adjusting a catalyst degradation threshold in response to a slope of a catalyst monitor sensor output; indicating catalyst degradation in response to a variable not exceeding the catalyst degradation threshold; and adjusting a state of an actuator in response to the indication of degradation.
By adjusting a catalyst diagnostic limit in response to an attribute of a catalyst monitor sensor, it may be possible to provide the technical result of improving catalyst diagnostics. In particular, an output voltage of a catalyst monitor sensor may change with age such that when the catalyst monitor sensor is part of a diagnostic to determine catalyst performance, catalyst oxygen storage may be overestimated. However, the catalyst oxygen storage estimate limit and a threshold amount of fuel provided to reactivate the catalyst may be adjusted to compensate for the catalyst sensor dynamics. Specifically, the oxygen storage estimate limit and the threshold fuel amount to reactivate the catalyst and provide rich exhaust constituent breakthrough downstream of the catalyst may be increased in response to a change in catalyst monitor sensor slope, or alternatively the catalyst monitor sensor time constant.
The present description may provide several advantages. For example, the approach may provide more reliable catalyst diagnostic evaluations. Further, the approach may reduce vehicle emissions via providing an indication of degraded catalyst operation. Further still, the approach may comply with on board diagnostic regulations.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.

Systems and methods for improving catalyst diagnostics in the presence of sensor degradation


Embodiments may be generally directed to techniques to cause communication of a registration request between a first end-point and a second end-point of an end-to-end path, the registration request to establish resource load monitoring for one or more resources of the end-to-end path, receive one or more acknowledgements indicating resource loads for each of the one or more resources of the end-to-end path, at least one of the acknowledgements to indicate a resource of the one or more resources is not meeting a threshold requirement for the end-to-end path, and perform an action for communication traffic utilizing the one or more resources based on the acknowledgement.

Many modern applications have demanding resource requirements that are difficult to support and scale. An effective way to scale such applications is to distribute individual tasks onto different processing elements and interconnect those processing elements on a switch fabric. This arrangement may support the high-bandwidth data flows that must exist between the tasks for the applications.
A high performance switch fabric arrangement may be achieved by use of various proprietary multi-stage switching technologies, but the performance is achieved at a high cost in dollars and in features, such as scalability. In order to achieve high performance at a reasonable cost, current approaches include sharing resources between applications. However, usage of these resources must be controlled to ensure that quality of service requirements for each of the applications is being met.

Techniques to control quality of service for end-to-end paths in a compute environment


A magnetic resonance imaging (MRI) apparatus storage unit stores different eddy current correction parameters that respectively correspond to different imaging positions to correct for influence of an eddy current magnetic field. An eddy current correcting unit receives the waveform of the gradient magnetic field calculated in accordance with an imaging condition, performs calculation onto the received waveform using an eddy current correction parameter selected in accordance with an imaging position, and outputs the calculation result as a corrected waveform to a gradient magnetic field power supply.

A magnetic resonance imaging apparatus adds positional information to a magnetic resonance signal emitted from a subject by applying a gradient magnetic field thereto, and reconstructs an image based on this positional information.
The magnetic resonance imaging apparatus applies a gradient magnetic field in pulse form. For this reason, an eddy current appears in conductive components arranged around the gradient coil (e.g., a heat shield for a magnetostatic magnet), and this eddy current generates a magnetic field (hereinafter, "eddy current magnetic field"). The eddy current magnetic field acts in a direction of suppressing the changes of the gradient magnetic field and deforms the waveform of the gradient magnetic field. Thus, corrections of the waveform need to be made in consideration of the influence of the eddy current magnetic field, or otherwise the image reconstructed from the magnetic resonance signals would be degraded. For this reason, eddy current correction has been employed to correct the waveform of the gradient magnetic field.
In the eddy current correction, calculation is performed by use of a predetermined eddy current correction parameter (intensity and time constant) with respect to an ideal waveform of the gradient magnetic field so that a corrected waveform can be output as the result. The gradient magnetic field power supply (hereinafter, "gradient power source") applies a gradient magnetic field in accordance with the corrected waveform. With the eddy current magnetic field overlapping the gradient field, the waveform of the gradient magnetic field becomes closer to the ideal waveform.
Here, the eddy current magnetic field may have a long time constant or a short time constant. It has been considered that an eddy current magnetic field with a long time constant is the one that causes image degradation. Because the eddy current magnetic field with a long time constant has substantially the same influence onto all the positions in the imaging range, an eddy current correction parameter is prepared with reference to the center of the magnetic field, and the correction is performed at all the positions with this parameter. However, a suitable correction may not always be performed for all the positions of the imaging range, and distortion or some other degradation may occur in the image, for example, at a position away from the center of the magnetic field.


Nucleic acids can be made available for amplification or other treatment after admixture of a sample with specific weakly basic polymers to form a precipitate with the nucleic acids at acidic pH. After removing non-precipitated materials, the pH is then made basic, thereby releasing the nucleic acids from the polymer. This method for preparing specimen samples is simple and quite rapid, and the released nucleic acids can be further treated in hybridization assays or amplification procedures. No surfactant or other cell lysing reagents are employed. The weakly basic polymers are water-soluble and cationic at acidic pH, but neutral in charge at basic pH.

Technology to detect minute quantities of nucleic acids has advanced rapidly over the last two decades including the development of highly sophisticated amplification techniques such as polymerase chain reaction (PCR). Researchers have readily recognized the value of such technology to detect nucleic acids which are indicative of diseases and genetic features in human or animal test specimens. The use of probes and primers in such technology is based upon the concept of complementarity, that is, the bonding of two strands of a nucleic acid by hydrogen bonds between complementary nucleotides (also known as nucleotide pairs).
PCR is a significant advance in the art to allow detection of very small concentrations of a targeted nucleic acid. The details of PCR are described, for example, in U.S. Pat. No. 4,683,195 (Mullis et al), U.S. Pat. No. 4,683,202 (Mullis) and U.S. Pat. No. 4,965,188 (Mullis et al), although there is a rapidly expanding volume of literature in this field.
In order to effectively amplify and detect a target nucleic acid, it is usually necessary to isolate that nucleic acid from cellular and other specimen debris. Various lysing procedures are known, including freezing, treatment with digesting enzyme such as proteases (for example, Proteinase K), boiling, and use of various detergents (see for example U.S. Ser. No. 178,202, filed Apr. 6, 1988 by Higuchi, and EP-A-0 428 197, published May 22, 1991), solvent precipitations and heating protocols.
Circulating DNA has been detected in blood serum and plasma. Nanogram quantities are detected in normal subjects (Steinman, C. R., J Clin. Invest. 56:512-515, 1975 and Raptis, L., et al., J. Clin. Invest. 66:1391-1399, 1980), and increased levels are detected in chronic autoimmune diseases (Leon, S. A., et al., Cancer Res., 37:646-650, 1977) and in cancer patients (Stroun, M., et al., Eur. J. Cancer Clin. Oncol. 28:707-712, 1987; Maebo, A., Jpn. J. Thorac. Dis. 28:1085-1091, 1990; Fournie, G. J., et al., Cancer Lett., 91:221-227, 1995; Lin, A., et al., BioTechniques 24:(6) 937-940, 1998; and Sorenson, G. D., et l., Cancer Epidemiology, Biomarkers and Prevention 3:67-71., 1994). Recently, it has become evident that free extracellular DNA present in blood serum and plasma can be used for genotype analysis (Lin, A., et al., BioTechniques 24:(6) 937-940, 1998), for detection of cancer (Mulcahy, H. E., et al., Clin. Cancer Res. 4:271-275, 1998), and DNA in maternal serum may be used in prenatal diagnostics (Lo Dennis, et al., Am. J. Human Genet. 62:768-775, 1998). Mutations present in a primary tumor, often can be detected using DNA from blood plasma or serum DNA (Sorenson, G. D., et al., Cancer Epidemiology, Biomarkers and Prevention 3:67-71., 1994; Vasyukhin, V., et al., In Challenges of Modern Medicine, Vol. 5, Biotechnology Today, R. Verna, and A. Shamoo, eds, 141-150. Aera-Serono Symposia Publications, Rome; Mulcahy, H. E., et al., supra.; Kopreski, M. S., et al., Brit. J. Cancer 76:1293-1299, 1997; Chen, X., et al. Nature Medicine 2: 1033-1035, 1996; Vasioukin, V., et al., Brit. J. Haematology 86:774-779, 1994; and Tada, M., et al., Cancer Res. 53:2472-2474, 1993). Thus, DNA present in serum and plasma represents a minimally invasive source for information related to cancer diagnosis, prognosis, and therapy.
To effectively amplify and detect a target nucleic acid, it is usually necessary to separate the nucleic acid from interfering substances present in a specimen of interest. Several different approaches have been used to concentrate and purify DNA from blood serum or plasma. Many of these methods involve multiple steps including phenol, ether, and chloroform treatment, dialysis, passage through Concanavalin A-Sepharose to remove polysaccharides and then centrifugation in a cesium chloride gradient (Vasyukhin, V., et al., supra.). More recently, Qiagen has commercialized a system for DNA concentration and purification based on a spin column protocol. The Quiagen protocol is complex, involving a total of eight steps, treatment with a protease, incubations at 70° C., and requires the use of at least 3 different buffers, in addition to a silica spin column centrifugation step.
Recently, Goecke et al. (WO 97/34015) reported the detection of extracellular tumor-associated nucleic acid in blood plasma and serum using nucleic acid amplification assays. In their preferred method, DNA is co-precipitated from plasma and serum using a multistep protocol involving an initial co-precipitation by gelatin, followed by solvent treatment and centrifugation. Other time-consuming and complex protocols involving the use of glass beads, silica particles or diatomaceous earth for extraction of DNA from serum and plasma are also described.
The use of weakly basic polymers for the capture and selective release of nucleic acids has been described U.S. Pat. No. 5,622,822 (Ekeze et al.), U.S. Pat. No. 5,582,988 (Backus et al.), and U.S. Pat. No. 5,434,270 (Ponticello, et al.). The protocols described in the aforementioned patents depend upon the use of a cell lysing agent or a cell lysing step. Surfactants are often used as cell lysing agents. The use of surfactants and other lysing agents results in the release of nucleic acids from cells and cellular components in blood; causing a large concentration of background DNA.

Rapid and efficient capture of DNA from sample without using cell lysing reagent


A spark plug including a cylindrical insulator having an axial hole extending in an axial direction; a center electrode held in the axial hole on a leading end side; a connecting terminal held in the axial hole on a trailing end side; and a sealing layer provided in the axial hole and including a glass sealing material containing a glass component and a metallic component, the sealing layer including a first sealing layer containing a first glass sealing material and a second sealing layer containing a second glass sealing material laminated in an axial direction of the axial hole, the first sealing layer contacting the center electrode, and the second sealing layer contacting the connecting terminal, wherein the second glass sealing material has a fluidity higher than that of the first glass sealing material at a temperature higher than a softening point of a glass component in the sealing layer.

1. Field of the Invention
The present invention relates to a spark plug for use in ignition of an internal combustion engine.
2. Description of the Related Art
A spark plug is conventionally used for ignition of an automobile engine. A spark plug generally includes: an insulator holding a center electrode on the leading end side of an axial hole and a connecting terminal on the trailing end side; a metal shell holding the insulator while enclosing the trunk portion thereof; and an earth electrode having one end thereof welded to the leading end of the metal shell and its other end opposed to the leading end of the center electrode to form a spark discharge gap.
The center electrode and the connecting terminal are electrically connected in the axial hole of the insulator through a conductive sealing member (or a sealing layer) (as disclosed, for example, in JP-A-2003-22886). Generally, the conductive sealing member is made from a mixture of a metal and glass to impart conductivity by dispersing metal powder into insulating glass. The center electrode and the connecting terminal are fixed in the axial hole by means of the sealing member.
In manufacturing the spark plug, the center electrode and the connecting terminal in the axial hole of the insulator are fixed in the following manner. First, the center electrode is inserted into the axial hole of the insulator from the trailing end side and is retained on a stepped portion in the axial hole, and the axial hole is filled from the trailing end side with the sealing member powder. Next, at a glass sealing step, the insulator is inserted into a heating furnace so that the sealing member is softened, and a connecting terminal is press-fitted from the trailing end side of the axial hole and sintered. Through these steps, the center electrode and the connecting terminal are fixed to seal the axial hole. This sealing step is called a "glass sealing step".
3. Problems to be Solved by the Invention
In order to realize a higher engine output, the valve employed for intake and exhaust is large-sized in recent years so as to considerably vibrate the engine. Vibration shocks thus applied to the spark plug which is mounted in the engine are also applied to the sealing member through the center electrode. However the sealing structure of a conventional spark plug may have insufficient shock resistance. To solve this problem, the shock resistance can be enhanced, for example, by increasing the content of the metallic component in the sealing member. However, the fluidity of the resulting sealing member is lowered such that it cannot flow sufficiently into the clearance between the inner circumference of the axial hole of the insulator and the outer circumference of the connecting terminal. This in turn causes another problem in that the connecting terminal is inadequately fixed to the insulator.
The present invention has been conceived in order to solve the aforementioned problem, and an object thereof is to provide a spark plug which can enhance the gas-tightness of an axial hole of an insulator and which can ensure adequate fixing of a connecting terminal and a center electrode in the axial hole.


Configurable user interface systems for a patient support structure are disclosed. As described a control interface comprises the capability to allow limited impact on processes deemed important when other applications and programs are run. The configurable user interface systems described herein allow for customized display of information and display options available to a user in various environments.

The present disclosure relates to hospital beds and particularly the user interface systems for hospital beds. More particularly, the present disclosure relates to configurable user systems for hospital beds. While several systems and methods exist for configuring user systems for hospital beds, a need exists for continued development in this area.

Configurable user interface systems for hospital bed


An armature assembly is provided for use in a solenoid actuator assembly having an energizable coil. The solenoid actuator assembly includes a housing and a bore disposed in the housing. The armature assembly has an outer surface and is positioned in the bore for axial sliding movement. The armature assembly has an outer surface which is of a diameter significantly less than a diameter of the bore and defines a fluid passage through the bore. Sleeve bearings are positioned at preselected spaced locations within the bore and extends about and in contact with a shaft of the armature assembly.

Solenoid actuator assemblies are well known in the art for actuating pilot valves. Pilot valves are utilized to control fluid operated systems, for example, implements, transmissions, engine fuel injector systems, and the like. In applications where the position of the pilot valve is either open or closed and does not require accurate modulation a conventionally constructed solenoid actuator assembly of relatively primitive design is satisfactory. Such conventional solenoid actuator assemblies typically utilize component parts that have a large mass since controllability, dampening, responsiveness, and other such functional characteristics are not important. In some systems functional characteristics such as accuracy, smoothness, and responsiveness of control is extremely important. In such applications a proportional solenoid actuator assembly is more suitable.
A proportional solenoid actuator assembly has an output force which is proportional to the electrical current applied to the coil and is independent of the armature position over the range of the armature stroke. This proportionality allows for precise positioning of a pilot valve by selectively applying full or partial electrical current to the solenoid coil and thereby varying the output force. An example of a proportional solenoid actuator assembly is shown in United States Pat. No. 5,208,570 dated May 4, 1993 to Andrew H. Nippert, the inventor of this invention. Such solenoids have performed well, however, they tend to be difficult to manufacture and assemble.
The armature of proportional solenoid actuator assemblies also have mass which is greater in magnitude than that required to forcibly move the pilot control valve. As indicated above, any extra mass, affects the operating characteristics, however, the extra mass may be necessary to provide satisfactory operation based on other functional and structural design parameters.
The extra mass in some proportional actuator assemblies is included in the length of the armature in order to provide satisfactory sliding motion of the armature in the bore of the housing. Since surfaces of the armature and the bore of the housing define the axial sliding bearing surfaces of the armature, it is necessary to provide a bearing fit between the surface of the bore and the surface of the armature. This requires tight tolerances and smooth surfaces on the mating pieces. As a result, the time of manufacture is substantially increased and also the associated cost of manufacture.
In solenoid actuator assemblies having a combination of armature shaft slidably disposed in a sleeve bearing and the armature slidably disposed in the housing bore, as discussed above, axial alignment and concentricity between the spaced apart sleeve bearing and the housing bore is critical. Since the bore of the sleeve bearing and the bore defining the housing bearing are of different diameters the ability to maintain alignment and concentricity within acceptable tolerances is extremely difficult. Therefore, a substantial amount of rework and scrap is generated resulting in a further increase in the cost of the solenoid actuator assemblies.
Prior solenoid actuator assemblies used in fluid operated applications required the addition of axial passages in the armature to permit the flowing of fluid between opposite ends of the aperture in order to prevent a hydraulic locking of the armature. These passages also served to dampen armature movement and to improve armature stability. The addition of these apertures adds to the time and cost of manufacture of the solenoid actuator assembly.
State of the art actuator assemblies consist of a substantial number of piece parts which increases the amount of assembly time. Also, many of the piece parts are thin in crossection making it difficult to permanently connect them together by known processes such as welding, brazing, and the like without causing distortion.
The present invention is directed to overcoming one or more of the problems as set forth above.


A display screen device includes a display panel on which a first image is displayed, and an electroluminescent display which displays a second image and is positioned to extend substantially entirely over one surface of the display panel so that the first image and the second image can be selectively displayed and so that the first image and the second image can be displayed in a superimposed manner.

1. Field of the Invention
The present invention relates to a screen upon which an image (as a picture or information) is projected to display the image on the screen, and more specifically, relates to a display screen which can either selectively display a plurality of images thereon or display a plurality of images in a manner so as to overlay one image on another.
2. Description of the Prior Art
In regard to a display screen for displaying an image, a projection display screen and a transmissive display screen are two possible types. A projection display screen consists of a blank surface and a support structure used with, e.g., a projector. A transmissive display screen consists of a transparent plate a surface of which is formed as a milk-white (translucent-white) surface. For instance, a transmissive display screen is often used as a focusing screen, which serves as an optical element of an single-lens-reflex camera, or a display screen of a liquid crystal display (LCD) or a cathode-ray tube (CRT). The focusing screen is made of a transparent resin plate, a surface of which is roughened (formed to be a light-diffusing surface) to allow a real image of an object to be formed on the roughened surface so that the real image can be viewed due to an optical effect at the roughened surface.
Conventionally, various photographic information are displayed on the focusing screen using a display device so as to be visually readable together with (or separately from) an object image (optical image) formed on the focusing screen. An LCD is generally used as such a display device. Visual information displayed on the LCD is formed at a position on an optical axis which is optically equivalent to the position of the focusing screen by an optical device. In Japanese unexamined patent publication 2000-137268 and Japanese patent publication No. 3539251, a device for displaying required images on the focusing screen using an EL (electroluminescent) display instead of an LCD has been proposed. Specifically, in the former publication, forming an EL display in a peripheral part of the object image forming area (picture area) of a focusing screen and making the EL display indicate required information by making an EL drive circuit drive the EL display makes it possible to view either only the required information or the required information together with an object image displayed on the focusing screen through a viewfinder. Furthermore, the latter publication discloses a system wherein an EL display is overlaid on a focusing screen to display a picture frame on the focusing screen. In the former publication, a system wherein an EL display is provided on a surface of a prism serving as an element of a viewfinder optical system has also been proposed.
In either a conventional projection display screen or a conventional transmissive display screen, the display screen is used to display only one image, and it is difficult to display different images in a manner to overlay (superimpose) one image on another. Although an object image and visual information can be simultaneously displayed by an arrangement in which an EL display is disposed on an image forming surface of either a focusing screen or a prism in the system disclosed in the former publication, an object image and visual information cannot be displayed simultaneously in an superimposed manner because the EL display is disposed outside of the effective field of view, in which an object image is displayed. In addition, images displayed on the focusing screen are limited to object images which are formed via a photographing lens because the EL display displays only visual information. On the other hand, although an image displayed on the EL display is displayed to be superimposed on an object image on the focusing screen in the system disclosed in the latter publication, the system disclosed in the latter publication is the same as that in the former publication in that images displayed by the EL display are limited since the image displayed by the EL display are unchangeable images which are predetermined beforehand. Therefore, in either of the former and latter publications, the degree of flexibility in images displayed on the display screen is low.


Apparatus and method to move granular materials in an even flow by centrifugal force from a rotating surface to a plurality of circumferentially arranged receiving points includes a rotatable inverted cone provided with a peripheral base flange and having an angle of inclination of the cone surface matching the angle of repose for the material to be distributed. Material delivered to the apex of the cone flows by gravity down the cone surface to establish the angle of repose for such material with a toe point at the flange where it comes to rest when the cone is stationary. A cylindrical hopper, to accumulate material from the cone, is vertically adjustably secured to the flange so that the bottom of the hopper is spaced above the flange to define a flow passageway which can be enlarged or reduced by vertical adjustment of the hopper relative to the flange. Rotation of the cone at a relative slow speed creates a sufficient centrifugal impulse at the toe point to initiate material movement at such point over the flange into the receiving points as the angle of repose continually moves to correct itself. The size of the flow passageway provides a means to precisely control the volume of material flow off of said flange at any selected time by not only adjusting such size but also by selectively increasing and decreasing the speed of rotation relative to such adjustments.

This invention relates to improvements in apparatus and methods that utilize centrifugal force for distributing granular materials in an even flow over the edge of a rotating surface to a plurality of circumferentially disposed receiving points.
Such types of apparatus are disclosed in many prior devices in a variety of forms in an environment where material is delivered to the axial area of a rotatable disc which is rotated at a speed fast enough to create a centrifugal force of sufficient impulse to urge such material centrifugally outwardly from the axial area towards and over the edge of the disc to a receiving point. In some instances, the movement of material is assisted by spider arrangements, agitators and valves and, because of the substantial centrifugal force required to move the material from the axial area to the edge of the disc, the use of a centering hopper attached to the disc for rotation therewith, has been used to impart some initial motion to the material delivered to the disc through such hopper. With such types of apparatus that use the rotating disc, it is well known that at any given speed of rotation, the centrifugal speed and impulse will be much greater at the perimeter than at the axis so that in such apparatus, the speed of rotation required to produce a centrifugal impulse sufficient to get the material in motion from the axial area and move it across the surface of the disc to and over the discharge edge thereof results in such a substantially greater centrifugal force and speed at the discharge edge that any precise control of the speed and volume of material flow to points of receipt is extremely difficult and is a serious disadvantage of known devices.
With the above observations in mind, it is one of the important objects of this invention to overcome the disadvantage noted and to provide a material distributor for moving granular materials over the edge of a rotating member to selected receiving points during which the speed and volume of material being moved can be precisely controlled.
Another object herein is to provide apparatus and method of the above class in which granular material is delivered to the peripheral area of a rotatable surface and is moved centrifugally outwardly from said area to selected receiving points by rotating said surface at a speed only sufficient to initiate movement of said material at said peripheral area.


A low price image display device which has a smaller number of mounted components and allows high-accuracy display, is provided by making proper use of both a high-accuracy, low-voltage DA converter IC and a DA converter circuit having high-voltage TFTs formed on an insulated substrate in accordance with a display signal value.

Related arts are hereunder explained with FIGS. 12 and 13.
Firstly, the structure of a first embodiment in the related arts is explained with FIG. 12. FIG. 12 is a circuit configuration diagram of a liquid crystal display by a related art. Each of the pixels constituting a display screen 203 includes a pixel switch 202 and a liquid crystal capacitor 201, and counter electrodes of the liquid crystal capacitors 201 are connected commonly to each other. The gate of each pixel switch 202 is connected to a gate wire driver IC (Integrated Circuit) 207 via a gate wire 204 and the other terminal of each pixel switch 202 is connected to a liquid crystal driver IC 208 having a DA converter circuit via a signal wire 205.
Here, the display screen 203, the gate wires 204, and the signal wires 205 are formed on a glass substrate 206. As a pixel switch 202 which is an active element, an amorphous silicon TFT (Thin Film Transistor) is used.
Next, operations of the first embodiment in the related arts are explained.
When the liquid crystal driver IC 208 applies an analog signal voltage to the signal wires 205 on the basis of input digital image data, in synchronization with that, the gate wire driver IC 207 selects prescribed gate wires 204 and turns on the pixel switches 202 in corresponding rows. Thereby, the analog signal voltage which the liquid crystal driver IC 208 has output is written in the liquid crystal capacitors 201 of the selected pixels and an optical image is displayed.
By such a related art, it is possible to display an image on the basis of input digital image data and the related art is now widely used for a liquid crystal display using the amorphous silicon TFTs.
In the meantime, a technology on a liquid crystal display using polycrystalline silicon TFTs which is different from the aforementioned technology is also known well. The structure of such a second embodiment in the related arts is hereunder explained with FIG. 13.
FIG. 13 is a circuit configuration diagram of a liquid crystal display showing the second embodiment in the related arts. Each of the pixels constituting a display screen 203 includes a pixel switch 202 and a liquid crystal capacitor 201, and counter electrodes of the liquid crystal capacitors 201 are connected commonly to each other. The gate of each pixel switch 202 is connected to a vertical scanning circuit 210 via a gate wire 204 and the other terminal of each pixel switch 202 is connected to a DA converter circuit 211 via a signal wire 205.
Here, the display screen 203, the gate wires 204, the signal wires 205, the vertical scanning circuit 210, and the DA converter circuit 211 are formed on a glass substrate 206. Then polycrystalline silicon TFTs are used as a pixel switch 202 which is an active element and the constituent elements of the vertical scanning circuit 210 and the DA converter circuit 211.
Next, operations of the second embodiment in the related arts are explained.
When the DA converter circuit 211 applies an analog signal voltage to the signal wires 205 on the basis of input digital image data, in synchronization with that, the vertical scanning circuit 210 selects prescribed gate wires 204 and turns on the pixel switches 202 in corresponding rows. Thereby, the analog signal voltage which the DA converter circuit 211 has output is written in the liquid crystal capacitors 201 of the selected pixels and an optical image is displayed.
By such a second related art, it is possible to display an image on the basis of input digital image data and details of such a related art are described in JP-A No. 005716/2003 for example.


Different mechanisms are provided to enable a gaming machine to download files/images, move/copy the files/images from one folder to another without breaking authentication, and resume interrupted file manipulation operations such as move/copy operations and/or download operations which have been interrupted by a power hit. In this way, the technique of the present invention is able to provide a self-diagnostic system for ensuring authenticated, atomic transactions, and for automatically handling detected error conditions. Additionally the technique of the present invention is able to provide a mechanism for seamlessly updating gaming machine components at runtime. This may include, for example, the automatic mounting and/or unmounting of selected games to/from the gaming machine memory during runtime.

This invention relates to gaming machines such as slot machines and video poker machines. More particularly, the present invention relates to a technique for implementing a downloadable software system for an electronic gaming machine communications network.
In general, conventional gaming machine networks typically include a central system operatively connected to one or more individual gaming machines via intermediate communication site controllers. Although the gaming machines communicate with the central system, each gaming machine or site controller contains a central chipset which locally stores the computer code to be is executed by the device to perform gaming related functions. These chipsets typically include electronic programmable read only memory (EPROM) which permanently store the computer code. EPROM chipsets are conventionally preferred because the electronic memory can be controlled in a secured manner without giving unauthorized access to the gaming machine code. Additionally, in many conventional gaming machine implementations, the gaming machine file systems have been designed and signed to meet stringent authentication and other security requirements. As a result, such file systems are typically implemented as fixed, read-only file systems. There is typically no need for implementing any type of file system management component (e.g., during initialization and/or run-time) for such file systems.
While such gaming machine implementations may provide one approach for minimizing security risks, such implementations do not offer flexibility with regard to configuring or reconfiguring gaming machine code. For example, in the event the gaming machine software code needs to be upgraded, service personnel are required to manually change the chipset for each gaming machine and/or site controller.
Because a service technician must perform the same operation for each machine or controller, the current method of updating gaming machine/site controller or gaming machine software typically takes a long time to accomplish at a substantial cost, including the cost of the technician time and the cost of a new chipset for each machine.
In light of the above, it will be appreciated that there exist a need for improving conventional techniques for dynamically updating or modifying gaming machine components.

Gaming machine update and mass storage management


A medical device includes a body and at least one electrode disposed thereon. The electrode includes a metallic substrate, such as a platinum group metal, an alloy of platinum group metals, or gold. The surface of the substrate is modified in a manner that increases its effective surface area without inducing bulk heating. For example, the surface of the substrate can be laser textured and/or coated, such as with titanium nitride or iridium oxide.

The instant disclosure relates to catheters for use in medical procedures, such as electrophysiology studies. In particular, the instant disclosure relates to electrophysiology catheters that include electrodes with increased surface area and decreased impedance.
Catheters are used for an ever-growing number of procedures, such as diagnostic, therapeutic, and ablative procedures, to name just a few examples. Typically, the catheter is manipulated through the patient's vasculature and to the intended site, for example, a site within the patient's heart.
A typical electrophysiology catheter includes an elongate shaft and one or more electrodes on the distal end of the shaft. The electrodes may be used for ablation, diagnosis, or the like. Oftentimes, these electrodes include ring electrodes that extend about the entire circumference of the catheter shaft, as well as a tip electrode.
As the dimensions of a measurement electrode decrease, the complex AC impedance with respect to a counter-electrode will generally increase. The increased impedance associated with smaller measurement electrodes can have undesirable effects during electrophysiology studies, such as electroanatomical mapping.
There are two primary contributing factors to the increased impedance. A first contributing factor is related to the dimensional dependence of the volumetric resistance (i.e., smaller electrodes have regions of higher current density). A second contributing factor is related to the capacitance of the electrode (i.e., as electrode dimensions shrink, the ionic AC current can become limited by how much charge can build up at the electrode surface). The second contributing factor, therefore, depends upon the total microscopic surface area of the electrode versus the macroscopic dimensional surface area of the electrode.

Electrophysiology device with electrodes having increased surface area

St. Jude Medical, Cardiology Division, Inc.


An access server allows secure access to commonly used files stored on multiple file sources from a variety of client devices. The access server extracts a list of file sources associated with the user, and accesses each of those sources. The server is then configured to extract a list of most recently used files by the current user as well as information associated with those files. The access server also processes electronic mail attachments. The access server intercepts electronic mail messages containing attachments, and transmits the attachments to a file server.

In the present business environment users are increasingly dependent on access to electronic documents and other files for performing regular business functions. Historically, users stored files upon their local machines and when traveling stored the files on portable media. However, this practice was less than ideal as it did not allow multiple users to simultaneously access the newest version of a file, the size of the physical media limited the types of files that could be used, and the physical media were often unreliable.
As networking technology became more easily accessible, some solutions arose to allow users to access their files away from their home or work computers. Several operating systems enabled users to access files stored on remote networks through Internet gateways or TCP/IP enabled file sharing. However, security concerns often limited the usability of such solutions. In order to preserve the vital integrity of the files stored on local networks, such solutions often require users to employ client side Virtual Private Networking (VPN) connections to allow secure access to their remotely stored files. While VPN provides a tolerable level of protection to the remotely stored files, it presents a number of significant difficulties.
Firstly, configuring a client to use VPN requires both administrator level access to the client machine and a lengthy setup procedure. For situations where users wish to access their files from public machines such as those at a retail business center or an Internet cafe, this proves to be an intolerable inconvenience. Additionally, many client devices that have entered the market during the past few years such as data-ready cellular phones and Personal Data Assistants (PDA), lack robust support for VPN. Furthermore, VPN typically only allows access to one private network at a time, requiring users that seek to access multiple secure networks to disconnect from the first network before accessing the second network, rather than enjoying simultaneous access to both networks.
What is needed is a solution that allows users easy and secure access to important files on a variety of file sources.

Remote file management using shared credentials for remote clients outside firewall