In a field effect transistor including active layers having a heterojunction structure with at least two different semiconductor materials, a layer for supplying electrons is disposed opposite a drain electrode, in contact with a region of the active layers including a dopant impurity producing n type conductivity. Therefore, degradation of the electrical characteristics caused by trapping of electrons in a drain ohmic contact layer due to fluorine diffusing into the semiconductor layers is suppressed by supplying electrons from the layer opposite the drain electrode, thereby improving reliability of the field effect transistor including the heterojunction structure.

Extended Abstract WC2 pp.497-500 of Fifth International Conference on Indium Phosphide and Related Materials, held at Paris in France from 19th to 22nd Apr. 1993, discloses a prior art HEMT (high electron mobility transistor) shown in FIG. 12(a). FIG. 12(a) is a cross-sectional view illustrating the prior art HEMT structure with an n type InAlAs carrier supply layer on an InP substrate and with a Schottky forming layer on the n type InAlAs carrier supply layer. FIG. 12(b) is a diagram for explaining thermal degradation of the electrical characteristics of the HEMT.
In FIG. 12(a), reference numeral 101 designates a semi-insulating (hereinafter referred to as S.I.) InP substrate, numeral 102 designates an undoped InP layer having a thickness of about 10 nm, numeral 103 designates an undoped InGaAs channel layer having a thickness of about 20 nm, numeral 104 designates an undoped InAlAs spacer layer having a thickness of about 3 nm, numeral 105 designates an n.sup.+ type InAlAs electron supply layer having a thickness of about 15 nm and a dopant concentration of 3.times.10.sup.18 cm.sup.-3, numeral 106 designates a Schottky forming layer comprising such as undoped In.sub.0.75 Ga.sub.0.25 P and having a thickness of about 10 nm, numeral 107 designates an n.sup.+ type InGaAs ohmic layer having a thickness of about 20 nm and a dopant concentration of 5.times.10.sup.18 cm.sup.-3, numeral 108 designates a source electrode, numeral 109 designates a drain electrode, and numeral 110 designates a gate electrode.
In FIG. 12(b), the abscissa shows an annealing temperature (unit: .degree.C.), and the ordinate shows a sheet carrier concentration (unit: 10.sup.12 cm.sup.-2) of two-dimensional electron gas produced in the interface of the undoped InGaAs channel layer 103 at the side of the undoped InAlAs spacer layer 104. Circles, triangles and squares shown in the figure represent the cases where materials of the Schottky forming layer 106 are In.sub.0.75 Ga.sub.0.25 P, InP and InAlAs, respectively.
A description is given of the thermal degradation of the electrical characteristics of the HEMT. In the above-described literature, in order to investigate thermal stability of the HEMT shown in FIG. 12(a), Fujita, et al., the authors, prepared the same structures as the main structure of the HEMT shown in FIG. 12(a). Three kinds of semiconductor laminated structures were obtained by successively laminating the undoped InP layer 102, the undoped InGaAs channel layer 103, the undoped InAlAs spacer layer 104 and the n.sup.+ type InAlAs electron supply layer 105 on the S.I. InP substrate 101, and subsequently laminating the Schottky forming layers 106 respectively comprising In.sub.0.75 Ga.sub.0.25 P, InP and InAlAs. These laminated structures were annealed at 300.degree. C. or 350.degree. C. for five minutes in an ambient of nitrogen, and measurements of sheet carrier concentrations of the two-dimensional electron gas produced in the interface of the undoped InGaAs channel layer 103 at the side of the undoped InAlAs spacer layer 104 were conducted for the respective laminated structures. The results are as illustrated in FIG. 12(b). As is known from the figure, regardless of the materials of the electrode layers 106, In.sub.0.75 Ga.sub.0.25 P, InP and InAlAs, the sheet carrier concentrations decreased by annealing at 300.degree. C. or higher.
These results indicate that, when an HEMT is annealed at 300.degree. C. or higher, the electrical characteristics of the HEMT are thermally degraded and a desired sheet carrier concentration of the two-dimensional electron gas is not obtained, so that there occur problems, such as an increase in resistance of a region where the two-dimensional electron gas is produced, failing to obtain expected HEMT characteristics. Concerning this phenomenon, Fujita, et al. reported that the decrease in surface sheet carrier concentration could be attributed to an increase in surface depletion layer caused by surface deterioration of the InAlAs layer.
Meanwhile, the inventors of the present invention have studied the thermal degradation of the electrical characteristics of the HEMT, as described in Applied Physics Letters Volume 66 No.7 pp.863-865. FIG. 13 is a cross-sectional view illustrating a semiconductor laminated structure used for the studies, and FIG. 14 is a graph showing the results obtained from the studies. In FIG. 13, reference numeral 111 designates an S.I. InP substrate, numeral 112 designates an intrinsic (hereinafter referred to as i-) AlInAs buffer layer having a thickness of 2500 .ANG., numeral 113 designates an i-GaInAs channel layer having a thickness of 500 .ANG., and numeral 114 designates an AlInAs electron supply layer having a thickness of 340 .ANG.. The i-GaInAs channel layer 113 includes a two-dimensional electron gas layer 116 in the vicinity of the interface at the side of the AlInAs electron supply layer 114, and the AlInAs electron supply layer 114 includes a spacer layer 115, i.e., a layer portion where an Si planar doping is performed to a height of 20 .ANG. from the interface with the i-GaInAs channel layer 113.
In FIG. 14, the abscissa shows an annealing temperature (unit: .degree.C.), and the ordinate shows a relationship between sheet carrier concentration N.sub.s0 of a two-dimensional electron gas layer before annealing and sheet carrier concentration N.sub.s thereof after annealing, i.e., N.sub.s /N.sub.s0.
The studies were carried out as follows. The semiconductor laminated structure similar to the HEMT structure shown in FIG. 13, with the AlIAs electron supply layer 114 planar-doped with Si on the i-GaInAs channel layer 113, was annealed at different temperatures for fifteen minutes in the nitrogen ambient. Then, the sheet carrier concentrations of the two-dimensional electron gas layer 116 formed in the vicinity of the interface of the i-GaInAs channel layer 113 at the side of the AlInAs electron supply layer 114 were measured by Hall effect measurements. As shown in FIG. 14, also in the above-described semiconductor laminated structure, the sheet carrier concentration decreases by annealing, which implies that an HEMT with its electrical characteristics degraded is fabricated by including an annealing process.
FIG. 15 is a cross-sectional view illustrating a semiconductor laminated structure used in studies for identifying the causes of the thermal degradation of the electrical characteristics of the prior art semiconductor device. In the figure, reference numeral 21 designates an S.I. InP substrate, numeral 22 designates an i-AlInAs layer having a thickness of about 4000 .ANG., and numeral 23 designates an AlInAs layer doped with Si as a dopant impurity and having a thickness of about 1300 .ANG..
The semiconductor laminated structures as shown in FIG. 15 were respectively formed in an MBE (molecular beam epitaxy) chamber by successively laminating the i-AlInAs layers 22 and the Si planar-doped AlInAs layers 23 on the S.I. InP substrates 21. After taking the semiconductor laminated structures out from the growth chamber, annealing was conducted for the laminated structures at temperatures of 300.degree. C., 400.degree. C., and 450.degree. C. for fifteen minutes under the nitrogen ambient, respectively. Then, impurity species of the semiconductor laminated structures were measured by secondary ion mass spectroscopy (SIMS) measurement. The results of the impurity measurements are as illustrated in FIG. 16.
In FIG. 16, the abscissa shows a depth of the semiconductor laminated structure from its surface (unit: .mu.m), and the ordinate shows a fluorine concentration (unit: cm.sup.-3). White circles shown in the figure represent a fluorine profile for the as-grown semiconductor laminated structure, white squares represent a fluorine profile for the laminated structure that was annealed at 300.degree. C., white triangles represent a fluorine profile for the laminated structure that was annealed at 400.degree. C., and black squares represent a fluorine profile for the laminated structure that was annealed at 450.degree. C.
The following facts were found by the above-described studies. .sup.19 F (fluorine) was diffused into the semiconductor laminated structure by annealing, which was based on the results obtained by checking the whole mass of impurities and detecting the mass number 19 by SIMS measurement; the amount of .sup.19 F increases as annealing temperature increases; .sup.19 F was dominantly involved in the Si-doped layer; and .sup.19 F was also accumulated at the interface between the epitaxial layers and the substrate.
From these facts, it is found out that fluorine (.sup.19 F) diffuses into the semiconductor laminated structure during annealing, which has not ever been known. Because no fluorine was detected for other materials, except for the Si-doped AlInAs layer 23, it is reasonably thought that the fluorine diffusion is a phenomenon peculiar to the AlInAs layer 23 doped with a dopant impurity, such as Si. In addition, when the origin of fluorine was investigated, it was found that no fluorine was used in the growth chamber of MBE or MOCVD which was used for the growth of the semiconductor laminated structure and that no fluorine was actively supplied in the laboratory. However, fluorine of about 0.3 atomic % was detected by analyzing the surface of the Si-doped AlInAs layer 23 just after the growth by electron spectroscopy for chemical analysis (ESCA). From these results, it is concluded that a small amount of fluorine, produced from hydrogen fluoride (HF) used for the semiconductor fabricating processes, remains in the air in the laboratory, and the fluorine in the air is attracted to and absorbed on the surface of the Si-doped AlInAs layer 23 when its surface is exposed to the air, resulting in the diffusion into the AlInAs layer 23.
Further, changes on standing in respective profiles (not shown) before and after annealing were investigated for elements such as Si and nitrogen, except for fluorine, and the respective profiles before and after annealing were almost the same.
As described above, the fluorine in the air diffuses into the Si-doped AlInAs layer 23 by annealing, and the profiles of the other elements do not change by annealing. Consequently, this phenomenon, i.e., the fluorine adsorption and diffusion by annealing, is thought to cause the thermal degradation of the electrical characteristics of the semiconductor device.
In order to avoid the degradation due to the fluorine diffusion, the fluorine remaining in the air may be completely removed. However, generally, in a plant where semiconductor fabrication is performed, the fluorine in the air remains without being completely removed, and complete removal of the fluorine is very difficult. Therefore, it is difficult to avoid fluorine diffusion.
Consequently, as long as the fluorine diffuses by annealing from the surface of the AlInAs layer doped with a dopant impurity, such as Si, which surface is exposed to the air, it is impossible to avoid the thermal degradation of a semiconductor device including a AlInAs layer doped with a dopant impurity.
In addition, it was ascertained that the thermal degradation occurred by retaining a lower temperature than the annealing temperatures used for the above-described studies, for a long time. FIG. 17 is a graph showing a relationship between carrier concentration of the Si-doped AlInAs layer 23 and time of retaining the temperature when the semiconductor laminated structure shown in FIG. 15 was annealed at 200.degree. C. In the figure, the ordinate shows a carrier concentration (unit: cm.sup.-3), and the abscissa shows time of retaining a temperature (hr). As is known from FIG. 17, the carrier concentration is decreased when the retaining time exceeds 100 hours at a low temperature of 200.degree. C. This indicates that the thermal degradation of the semiconductor device occurs even at such a low temperature, and that the semiconductor device may be thermally degraded in the long term, even at a further low temperature, so that reliability of the semiconductor device is very low.
As described above, in a prior art semiconductor device including an AlInAs layer doped with a dopant impurity, like an HEMT, when thermal treatment is performed under an ambient including a carrier gas, such as nitrogen and hydrogen, degradation of the electrical characteristics, such as a decrease in sheet carrier concentration, occurs. Usually, in order to confirm reliability of a semiconductor device, the semiconductor device is operated at a high temperature, which is likely to degrade the semiconductor characteristics, thereby confirming changes of the characteristics on standing. In the prior art semiconductor device, however, because the sheet carrier concentration decreases in a reliability test including the thermal treatment, the obtained results are not satisfactory, failing to produce a semiconductor device having high reliability.
In addition, since the characteristics are thermally degraded as described above, it is very difficult to operate the prior art semiconductor device at a high temperature for a long time, while maintaining desired characteristics, which makes it difficult to provide a semiconductor device having high reliability in high-temperature operation.
Further, in a prior art method of fabricating a semiconductor device, when the fabricating method requires a thermal treating process at a high temperature after forming an AlInAs layer doped with a dopant impurity, the electrical characteristics of the AlInAs layer doped with a dopant impurity are thermally degraded, so that a semiconductor device having desired characteristics is not fabricated. For example, in an HEMT including the AlInAs layer doped with a dopant impurity as a carrier supply layer, the sheet carrier concentration of two-dimensional electron gas decreases due to the thermal degradation, so that desired operating characteristics are not obtained.


An electrical connector (1) comprises a mating cavity (147) defining a front-to-back direction for mating and unmating, a supporting bracket (14) defined in the mating cavity, and a printed circuit board (20), the supporting bracket comprising a front portion (144), the front portion comprises a top surface, the printed circuit board secured to the supporting bracket and comprises a plurality of conductive pads (21, 22, 23) formed thereon, and wherein the top surface of the front portion is higher than the conductive pads of the printed circuit.

1. Field of the Invention
The present invention generally relates to an electrical connector, and more particularly to a Universal Serial Bus Connector with a printed circuit board.
2. Description of Prior Art
Portable electronic devices are found more and more applications in human livings with rapid developments of the science and technology nowadays. A portable electronic device needs to get smaller and smaller on one hand for portability and to incorporate as many electronic components therein as possible on the other hand for functioning. Thus, electronic components accommodated in the portable electronic device and electrical connectors accommodated in the portable electronic device to connect peripheral electronic components, which are not put in the portable electronic device, to the portable electronic device are all made as small as possible.
Universal Serial Bus (USB) connectors are often used to connect peripheral electronic components, such as Hard Disk Drive and CD ROM, to portable electronic devices. A mini USB connector having a small size is widely used in MP3 player. The conventional mini USB connector comprises four contacts for mating with the complementary connector. But, in some specialist, the mini USB needs to mate with the connector having different pin count of contacts. As mentioned above, two different kinds of mini USB connectors are needed for mating with different connectors. Obviously, it increases the cost. A kind of connector has nine contacts is used for solving this problem. But it is difficult to assemble nine contacts on a tiny tongue. Therefore, a printed circuit board has a plurality of conductive pads replacing the tongue has a plurality of contacts.
When the complementary connector inserted into the USB connector having a printed circuit board, the conductive pads of the USB connector is scraped easily.
Hence, it is desirable to have an improved USB connector to overcome the above-mentioned disadvantages of the prior art.

Electrical connector with high durability cycles


A self-ventilating device for a shoe, including an air-pumping member disposed in the heel portion of the insole thereof, an ankle-protecting air bag disposed in the heel portion of the insole thereof, an ankle-protecting air bag disposed in the interior of the upper thereof, and an automatic air-controlling member communicating with the air-pumping member and ankle-protecting air bag, whereby the shoe can be effectively ventilated and protect the ankle.

1. Field of the Invention
The present invention relates to a self-ventilating shoe and, more particularly, to a shoe having an air-pumping member, an ankle-protecting member, and an automatic air controlling member connected to both air-pumping and ankle-protecting members, whereby the shoe can be continuously ventilated and can automatically control air-suction and air-expulsion of the ankle-protecting member.
2. Description of the Related Art
Presently known ventilated shoes comprise elastomeric and resilient pads which are made of soft materials such as sponge or rubber and contain a plurality of holes in the sole and in the heel of the shoe in order to increase foot comfort. In these types of insoles, it is very difficult to remove moisture and the odor produced as a result of moisture which collects in the shoe due to foot sweating caused by poor shoe ventilation. Since most people use their shoes for long periods of time, it is essential to properly maintain and ventilate the shoes in order to avoid foot diseases, such as for example, water-eczema.
Various types of shoes having an ankle-protecting member are known in the art. However, the ankle-protecting member has an air bag which can be pumped full of air by a pump and in which air is expelled by hand so that it is difficult to use and damages the ankle due to a tight squeeze of the ankle-protecting member.
According to a report of the American Podiatry Association, 75 percent of the males and females stand or walk for 4 hours a day. Such foot stress leads to foot problems, particularly in males where athlete's foot fungi and the odor associated therewith have become a common problem.
In order to avoid such problems, Korean Utility Model Publication 90-9004 issued by the present inventor, discloses a ventilated military shoe which includes lower, middle, and inner soles for introducing air and a heel portion for discharging air, respectively. However, this shoe is difficult to construct, expensive to manufacture, and does not ventilate as effectively as the instant invention.
Also, U.S. Pat. No. 5,068,981 issued by the present inventor, discloses a shoe ventilation system which includes an upper portion having an air inlet and an air outlet disposed in the upper portion thereof, respectively, and a one-way air flowing member disposed in the lower portion thereof, an inner sole having a plurality of holes in the sole portion thereof and a plurality of channels and an arch extended portion disposed in the bottom surface thereof for communicating with the air flowing member, whereby the interior of the shoe can be continuously ventilated. However, this shoe is complicated in structure and cannot control air-suction and expulsion by itself.

Self-ventilating shoe having an air-controlling device

Taepyungyang Apt. 6-405, 1774-1 Daeyun 6-Dong


Briefly, in accordance with one embodiment of the invention, a mobile unit may detect and connect to a wireless local area network, contemplating worldwide multiband networks and multiple regulatory domains, with a shorter searching time.

The time required for network connection is one technical parameter indicating performance of a wireless system. With regulatory limitations imposed on wireless communications, a mobile unit obtains regulatory information such as valid frequency channels and transmitting power levels, typically broadcast from the network itself, before connecting to the network. If there is no regulatory information broadcast from the network, or if the mobile unit does not support the regulatory standard, the mobile unit searches available channels using a passive joining method. Such a passive joining method may require some amount of time for the mobile unit to connect to the network, thereby impacting performance of the wireless system.
It will be appreciated that for simplicity and clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements are exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals have been repeated among the figures to indicate corresponding or analogous elements.


A board-handling mechanism for more easily installing and removing boards from motherboards and/or other mountings within system enclosures does not require the removal of the enclosure. The mechanism provides leverage to positively seat and unseat circuit boards mounted into system connectors on the motherboard or other locations within system enclosures. A cable loop connector is provided within the enclosure opposite the opening for engaging the I/O connector on the forward edge of the daughterboard. The cable loop connector is biased to an upper position so that the daughterboard will first seat in the cable loop connector before being lowered and engaged to the motherboard connector.

In computer systems, workstations and other electronics-intensive products and systems, ICs (integrated circuits) including processors, memory systems, controllers, logic circuits together with other system components and ASICs (application specific integrated circuits) are generally mounted on circuit boards within a system enclosure. The circuit boards are, in turn, generally coupled to connector terminals on a main system board or motherboard. The motherboard is typically positioned adjacent to, and mechanically supported by, one of the two major walls or panels of an enclosure. The motherboard is typically the largest board in the enclosure, and provides a stable support base for smaller circuit boards or so-called daughter boards, which may be inserted into connectors mounted on the motherboards.
In the prior art, a circuit board was installed into an enclosure by removing the main panel or wall of the enclosure in order to provide access to the connector on the motherboard and also to give an installer the leverage required to apply an in-line force to make certain a solid electrical connection is established and the daughterboard is securely connected. Even as systems are upgraded, and/or new functions or additional functions are implemented on new boards which need to be installed in existing systems and enclosures, or when boards need to be removed for troubleshooting or maintenance, a main panel or side of the electronics system enclosure needs to be fully removed.
In most system environments space is critical. In systems or network environments or host-terminal systems, servers or computer enclosures are usually mounted in close quarters or even in cabinets or equipment racks where access is extremely limited. In such environments, board replacement or installation is a major task since the enclosure needs to be brought out to an open area and one of the main panels has to be removed in order to have access to the motherboard and connectors within the electronics enclosure. In some cases, the server unit may be mounted on a slidable tray support and the server may be slidably removed from its normal operating position, but even in that case, a major panel of the enclosure must be removed to gain access to the enclosed circuit boards.
For circuit boards which must engage connectors on two of its perpendicular edges, usually the forward and lower edges, the problem is more advanced. Each of the connectors must be individually engaged with a significant amount of insertion force to properly seat. With the system enclosure in place, manipulating the circuit board and applying sufficient force to join the connectors is difficult.

Mechanism for inserting or removing I/O cards with internal connectors

International Business Machines Corporation


An apparatus includes at least one optical fiber device including a region, and a ferrule having an aperture therethrough filled with a metal alloy securing material therein. The metal alloy securing material is softened responsive to application of energy thereto, and the region of the optical fiber device is inserted therethrough for securing to the aperture of the ferrule.

1. Field of the Invention
The present invention relates to an apparatus for, and method of, forming a low stress tight fit of an optical fiber to an external element, and more particularly, to an apparatus for, and method of, accurately and reliably forming a low stress tight fit of an optical fiber to a ferrule.
2. Background of the Related Art
Currently, various techniques exist for stabilizing an optical fiber and/or device to an external substrate or connector system, such as a ferrule. For example, one technique involves using an epoxy to affix the optical fiber to an external substrate. Another technique disclosed in U.S. Pat. No. 5,475,784 to Bookbinder, et al. encapsulates a segment of organic material of an optical component, such as a junction, by directly placing molten metal around the component and solidifying the metal.
U.S. Pat. Nos. 5,293,582 and 5,261,019 to Beard et al. relate to a fiber optic connector including a ferrule assembly having a fiber within a ferrule. The ferrule is received within a hub held in a barrel. An inner spring urges the ferrule and hub outwardly from the barrel. A nut is movably attached to the barrel. An outer spring biases the barrel toward a connector end of a housing. The fiber is secured within a bore of the ferrule through any "commercially known means" (column 3, lines 12-14).
U.S. Pat. No. 5,381,497 to Toland et al. relate to a fiber optic connector including a ferrule received within a ferrule holder. The ferrule holder is provided with venting to evacuate air from an adhesive receiving chamber to avoid air pocket formation in adhesive.
U.S. Patent to Ziebol et al. relates to a connector including a crimp, a ferrule holder and ferrule. The crimp is generally cylindrical in shape and has a reduced diameter portion on one end. The crimp is received within a cylindrical cavity formed in the ferrule holder. The ferrule holder has a centrally disposed bore into which the ferrule is press fit. The fiber is physically retained by the crimp and free floating within ferrule. As a result, a length of the fiber is unsupported. The crimp is the only element of the connector having a grasping contact on the fiber.
In Ziebol et al., the fiber is retained within the crimp by positioning the fiber sheathed portion within an enlarged bore, and extending the remainder of the unsheathed fiber through a V-groove and another bore. The crimp is then forced within the body of the ferrule holder. The crimping action results in the fiber being securely and rigidly held between the three opposing surfaces of the V-groove.
However, the resulting secured optical fiber according to these prior techniques often times is not properly secured to the external substrate, and/or element, and/or ferrule. These processes are difficult to automate, and do not provide good yield results. For example, the use of epoxy makes the manufacturing process difficult. Similarly, the use of a crimping action can damage the ferrule and/or optical fiber.
It is therefore desirable to provide accurate and consistent production of optical fibers that are secured to an external substrate, element and/or ferrule, for strength, support, and protection.
It is also desirable to provide production techniques to secure optical fibers to an external substrate, element and/or ferrule.
It is also desirable to provide a procedure that allows a connector to be attached or secured to an optical fiber, ferrule, substrate and/or element, quickly, reliably, and inexpensively.
It is also desirable to provide a procedure to automate the attachment of connectors to optical fibers by field personnel.
It is also desirable to provide a procedure to automatically produce fiber optic patch cords and pigtails.

Apparatus for, and method of, forming a low stress tight fit of an optical fiber to an external element


A biodegradable absorbent mat for absorbing and containing moisture including debris from pet feet, consisting of a bottom layer formed of an organic absorbent mesh composite, a top layer affixed and overlying said bottom layer, having an alternating combination of stitched paper ruffles and helically intertwined brush fibers. The organic mesh composite may be burlap or paper, treated with starch for rigidity, and then coated with a natural gum or latex to enhance friction grip and provide a moisture barrier. The configuration of the stitched paper ruffles, provide maximum exposure of the cut linear edges of the ruffles to a pet's feet. The cut linear edges wick away moisture increasing the rate of absorbency. The stitched paper ruffles provide increased capacity for absorbency and debris containment. The helically intertwined brush fibers primarily remove debris from pet feet, and also provide a secondary function of containment of debris.

The invention relates to a biodegradable pet mat for absorbing moisture and containing debris from the feet of pets. In one embodiment, the mat consists of two layers, a bottom layer and a top layer. The bottom layer is formed of an organic absorbent mesh that can be treated to be rigid and non-skid when used on a smooth floor. The top layer is affixed and overlying said bottom layer, having alternating combinations of stitched paper ruffles and helically intertwined brush fibers. The stitched paper ruffles absorb moisture and contain debris, while the helically intertwined brush fibers dislodge and capture debris from the feet of pets.
The historical problem with having pets in a house is maintaining a clean environment for both the pet and human inhabitants. Pets track in moisture and debris. Pets also spill water and food, drool, and generally make a mess of their eating areas. Pets also drop body wastes when kept in a confined space. These wastes then may be carried on the pet's feet into the human living area causing sanitary and cleanliness issues.
In the case with cats, litter boxes are a constant source of maintenance and clean up, and the area around the box is beset with litter and body wastes that stick to the bottom of the cat's feet. The present invention provides for an inexpensive, biodegradable solution, that will absorb body waste moisture, dislodge litter and waste from the cat's feet, entrapping said litter, moisture, and waste into a biodegradable medium that can be disposed of in an environmentally friendly way.
One device addressing the eating area mess is a rubber mat having an irregular surface to be used as a placement mat for food and water dishes. (U.S. Pat. No. 4,907,539). This mat is not absorbent and not biodegradable. It also fails to entrap and hold drool, water, pet food, or other debris associated with pet feeding.
Another device is a rubber mat for protecting the floor of a pet confinement area having a plurality of protrusions and grooves to provide traction to pets. (U.S. Pat. No. 6,220,205). This pet area mat does not absorb moisture and fails to contain debris or other animal waste.
There are many devices used to help maintain litter box areas and aid in removing litter from the bottom of cat's feet as they exit the litter box. One such device is an artificial turf doormat that is places under the litter box to trap tracked out litter and body wastes. (U.S. Pat. No. 6,357,488). However, #488 does not absorb moisture, and body wastes can get trapped within the turf mat and under the litter box creating undesirable smells and bacteria Said trapped body wastes may pose a serious health threat for both cats and humans.
Another device designed to maintain litter box areas is a hard plastic, rubber, commercial grade carpet or combination thereof, that is placed next to the litter box. (U.S. Pat. No. 5,797,352). Again, #352 does not absorb pet waste moisture, the device only holds the litter and body waste, requiring the pet owner to manually clean and sterilize regularly.


A method for generating a code bridge between a client application and a target application, including generating a metadata file defining exposed interfaces for the client application and the target application, creating a schema defining the code bridge using the metadata file, and generating source code for the code bridge using the schema.

Organizations typically have multiple platform dependent and language (e.g., Java™, C++, .Net, etc.) dependent solutions to support various portions of their business and operation. For example, an organization may use Java™ to create a web-based solution to support the organization's e-commerce operation, and may purchase a .Net solution to support customer relationship management (CRM). If the organization wishes to integrate the two solutions, a "bridge" is required. The bridge, in this particular example, allows the .Net based CRM solution to interact with the Java™ based web-solution and vice versa.
There are three main categories of bridges: local, remote, and distributed. A local bridge is one, which will result in bridging two bodies of code existing in the same process (e.g., within the same application). A remote bridge is one, which will result in bridging two bodies of code existing in multiple processes (e.g., different application spaces). In the local bridge and the remote bridge solutions, portions of the bridge components will exist in both the bodies of code being bridged. In contrast, each component in a distributed bridge resides in a separate process, i.e., two bodies of code each exist in a separate process, and the bridge also resides in a separate process.
An example of a bridge technology that is currently available is the Java™ Native Interface (JNI). JNI is a model for bridging code based on the 'C' language standard. In the following descriptions of bridge architectures, the client code is that body of code attempting access to existing code, the target code is that pre-existing body of code which exists as an application or library. The following describes the typical steps involved in implementing a JNI-based solution for bridging a Java™-based application with Native 'C' code. First, the Java™-based application is created exposing native methods, i.e., methods implemented in 'C'. This is done by qualifying a method with the "native" keyword. The Java™-based application is compiled typically using "javac". The "javah" command with the -jni flag is then used to generate a 'C'-style header file containing method declarations for each method declared as "native." Using the generated 'C'-style header file, an implementation file is created containing an implementation function for each declared method in the 'C'-style header file. The implementation file is then compiled creating a native dynamic library. Additional Java™ code is then added to the Java™-based application to load the new dynamic library prior to the use of the native methods. The Java™-application is then re-compiled to produce the Java™-based application. Prior to running the Java™-based application, any changes to the environment to allow the dynamic library to be locatable and loadable are also performed. Once this is complete, the Java™-based application may be run. If the native code was re-written in C++, the above mentioned steps would have to be repeated to create a new bridge.

Method and apparatus for generating a code bridge


A device for encapsulating plastic waste such as plastic syringes with attached needles, lancets or blood test strips, having a melt chamber to receive the waste, means to elevate the temperature within the melt chamber, a reciprocating compaction head to compact the melted waste to form a plastic slug with the needles encapsulated within the slug, where the compaction head has a shoulder whereby the slug becomes attached to the compaction head when hardened. The hardened slug is then removed from the melt chamber during the retraction of the compaction head. Preferably, an ejection cam slides the plastic slug partially off the compaction head for easy removal.

This invention relates generally to the field of devices for the destruction, encapsulation or disposal of potentially hazardous plastic waste, especially such waste comprising used medical syringes with attached needles or lancets. More particularly, the invention relates to such devices which melt and compact the plastic waste to completely encapsulate the needles into a sterile, disposable slug.
It is necessary to dispose of used medical syringes, lancets and blood test strips in a manner which minimizes the possibility of injury or infection to persons handling the syringes, at the initial point of use and disposal as well as all along the handling chain to final disposition in a land fill or the like. Numerous methods or devices have been developed to address this problem. Some such devices provide means to cap or enclose the needle, but enclosure of the needle by a physical housing requires the person to perform an additional physical act where inadvertent contact is possible and does not address the need to sterilize the syringes to kill infectious organisms. Devices are also known which provide protection from the syringe needles by melting the plastic portions of the syringes such that the needles are encased in the resulting plastic mass. This technique is an improvement over the capping method, since the used needle is simply deposited into the disposal device with minimal handling. The temperature achieved within the melt chambers of these devices is greater than that required to melt the plastic in order to also sterilize the waste material.
Examples of such combination disposal and sterilization devices are shown in U.S. Pat. No. 4,800,958 to Yerman and in U.S. Pat. No. 5,207,994 to Suziki. These devices provide a cylindrical melting chamber with a reciprocating piston. The waste syringes are placed into the chamber, heated and compressed to form a puck or slug to encapsulate the needles. The plastic slug is then removed by opening separate access plates or doorways and disposed of.
Both of these devices, as well as all other similar known devices, involve multiple joints, doorways, hinges and other components which are susceptible to fouling from plastic flash. Plastic flash is molten plastic which escapes from the melting chamber due to the effects of gravity or pressure from the compacting piston. Syringe plastic contains paraffin, which becomes a highly viscous liquid at temperatures well below those required to sterilize the plastic waste. The sterilization step requires temperatures in excess of 350 degrees F. to achieve sterilization in a relatively short time period. During the melting process, at about 275 degrees F., the paraffin becomes a highly viscous liquid which is forced past the seals and joints in the known devices. To counter this, highly efficient seals and joints must be constructed with very tight precision. These air and fluid tight seals prevent the escape of water vapor, steam and other outgas products produced during the melting process. Since they cannot escape and are non-compressible, they recondense on or within the waste slug and create gaps and voids within the slug through which the needle points may be exposed.
It is an object of this invention to provide a device for the destruction, sterilization and encapsulation of hazardous plastic waste products, and in particular waste such as used medical syringes with attached needles, lancets, blood test strips or the like, which provides a safe and efficient means to form the plastic waste into a disposable plastic slug with the needles securely encased therein by combination of pressure and temperature. It is a further object to provide such a device which allows gas and liquids to escape from the melting chamber such that they are not retained within the waste slug. It is a further object to provide such a device which eliminates the problems associated with plastic flash by providing a melting chamber machined from a single block or cast to have no joints or seams, and which reduces the number of joints, seals and moving components required to accomplish the task in order to simplify the device. It is a further object to provide such a device in which a reciprocating compaction head for the plastic waste is constructed such that the waste slug becomes temporarily attached to the compaction head such that the plastic slug is removed from the melt chamber by retraction of the compaction head. It is a further object to provide such a device in which the compaction head is reciprocated by a rotating cam and in which the plastic slug is at least partially ejected from the compaction head by a second rotating cam.

Device for encapsulation of plastic syringes


A method of dimming a light source module including a light guide plate, a first light emitting module including first to k-th light source blocks, wherein the first light emitting module is disposed on a first edge of the light guide plate, and a second light emitting module including first to m-th light source blocks, the second light emitting module being disposed on a second edge of the light guide plate, the second edge disposed opposite the first, the method including; generating a first group of driving signals and a second group of driving signals based on an image signal and driving the first to k-th light source blocks using the first group of the driving signals during a first period in a reference period and driving the first to m-th light source blocks using the second group of driving signals during a second period in the reference period.

1. Field of the Invention
Exemplary embodiments of the present invention relate to a method of dimming a light source and a display apparatus for performing the method. More particularly, exemplary embodiments of the present invention relate to a method of dimming a light source capable of improving display quality and a display apparatus for performing the method.
2. Description of the Related Art
In general, a typical liquid crystal display ("LCD") apparatus includes an LCD panel displaying an image using light transmittance of liquid crystals and a backlight assembly disposed under the LCD panel to provide light to the LCD panel.
The typical LCD panel includes an array substrate having a plurality of pixel electrodes and a plurality of thin film transistors ("TFTs") electrically connected to the plurality of pixel electrodes, a color filter substrate having a common electrode and a plurality of color filters and a liquid crystal layer disposed between the array substrate and the color filter substrate.
Recently, in order to reduce power consumption of an LCD apparatus, dimming technology in which the backlight assembly is divided into a plurality of light emitting blocks and luminance of the light emitting blocks is individually controlled, has been developed.
In the recently developed dimming technology, a display of the LCD panel is analyzed and at least some of the light emitting blocks, may have the light transmittance thereof compensated according to the luminance of an image to be displayed on the LCD panel, so that the power consumption of the backlight assembly may be reduced and a contrast ratio may be increased.
In general, one-dimensional dimming technology may be used in the LCD panel which includes light sources disposed at least one of upper, lower, left and right edges of the LCD panel. The one-dimensional dimming technology includes small numbers of the light emitting blocks so that driving logic may be simplified. However, the power consumption may be increased and the display quality such as the contrast ratio may be decreased when bright images such as subtitles are displayed on several light emitting blocks.

Method of dimming a light source and display apparatus for performing the method


A cross-track plunging constant velocity joint assembly includes an inner race having an outer diameter, an axial length, inner ball tracks, and a spline engageable with a first torque transfer member. An outer race has an inner diameter, an outer diameter, and outer ball tracks. The outer race is connectable to a second torque transfer member. A cage having multiple windows is disposed between the inner and outer races. A plurality of balls (N) having a ball diameter are held by the cage within the windows and engage pairs of the inner and outer ball tracks. The balls define a joint pitch circle diameter (PCD). The inner race has a plunge depth within the outer race. The ratio of 1.2≦(outer race outer diameter/outer race inner diameter)≦1.7 is satisfied.

Constant velocity joints connecting shafts to drive units are common components in automotive vehicles. The drive unit typically has an output shaft or an input shaft for receiving the joint. Typically, the drive unit is an axle box, transfer case, transmission, power take-off unit or other torque device, all of which are common components in automotive vehicles. Typically, one or two joints are assembled to the shaft to form a propeller or drive shaft assembly. The propeller shaft assembly may be connected, for instance, at one end to the output shaft of a transmission and, at the other end, to the input shaft of a differential. The shaft may be solid or tubular with ends adapted to attach the shaft to an inner race of the joint. An outer race of the constant velocity joint may be connected to the drive unit. The inner race of the joint is typically press fit, splined, or pinned to the shaft, making the outer race of the joint available to be bolted or press fit to a hub connector, flange or stubshaft of the particular drive unit. At the other end of the propeller shaft, a similar connection is made to a second drive unit when connecting the shaft between the two drive units.
Motor vehicles may use propeller or drive shafts to transfer torque via the constant velocity joint from the one input unit to an output unit, for example, from a front drive unit to a rear axle differential such as in rear wheel and all wheel drive vehicles. Propeller shafts are also used to transfer torque and rotational movement to the front axle differential in four-wheel drive vehicles. In particular, two-piece propeller shafts connected by an intermediate joint are commonly used when larger distances exist between the front drive unit and the rear axle of the vehicle. Similarly, inboard and outboard axle drives are commonly used in motor vehicles to transfer torque from a differential to the wheels. The torque transfer is achieved by using a propeller shaft assembly consisting of one or two joints assembled to an interconnecting shaft in the manner indicated above.
Joint types that may be used include Cardan, Hooke or Rzeppa type universal joints. Typically, Rzeppa type constant velocity joints are employed where transmission of a constant velocity rotary or homokinetic motion is desired or required. Constant velocity joints include tripod joint, double offset joint, and cross groove designs having plunging or fixed motion capabilities. The tripod type constant velocity joint uses rollers or trunnions as torque transmitting members and the other constant velocity joint types use balls as torque transmitting members. These types of joints assembled to an interconnecting shaft are applied in inboard axle and outboard axle drives for front wheel drive vehicles and on the propeller shafts found in rear wheel drive, all-wheel-drive, and four-wheel drive vehicles allowing for angular articulation or axial motion. As between the fixed and plunging types of constant velocity joints, the plunging joint typically experience more noise, vibration and harshness ("NVH") issues due to sliding forces as well as clunking noise due to joint tolerances.
The torque transfer capability of a cross-track constant velocity joint is also influenced by its moment of inertia, which is primarily a function of the maximum radii of the constant velocity joint's parts, rather than their mass. Thus, it would be desirable to have an improved cross-track constant velocity joint that benefits from the torque transfer to radius relationship to reduce the mass of the assembly. Moreover, a cross-track constant velocity joint that provides a reduced package size for a particular application would also be of benefit. Also, a cross-track constant velocity joint with optimized ratios would provide additional benefits, such as weight reduction, package size control, reduced part envelope and/or part runout, improved vibration deadening, increased strength per package size, and increased torque transfer capability per unit weight.

Plunging cross-track constant velocity joint


An oximeter machine includes a built in first socket that is positively engaged by a jack at the proximal end of a first cable. The distal end of the first cable includes a jack that engages the proximal end of a second socket. The proximal end of a second, adjustable length cable engages the distal end of the second socket and the distal end of the second cable engages the proximal end of a third socket. The proximal end of a third cable engages the distal end of the third socket and the distal end of the third cable is engaged to an oximeter finger sensor. A retractable cable housing enables the length of the second cable to be adjusted so that its length may be minimized to reduce cable tangling and to minimize a tripping hazard.

1. Field of the Invention
This invention relates, generally, to oximeter machines and to combination oximeter/EKG machines. More particularly, it relates to a structure and method for preventing oximeter cables from getting into a disorderly condition.
2. Description of the Prior Art
Oximeter cables are lengthy. They extend from an oximeter machine or a combination oximeter/EKG machine to an oximeter finger sensor. A patient inserts a finger into the oximeter finger sensor.
The cables are long because oximeter machines (or combination oximeter/EKG machines) are often used in operating rooms where the machine must be positioned a substantial distance from a patient. As a result, the cables often wind up on the floor, walked upon by the members of a surgical team. The connection between the machine and the cable, at the proximal end of the cable, is easily broken when the cable is pulled. Thus, whenever someone trips over a cable and yanks it from the machine, the connection must be restored. The oximeter cable may also become tangled with other cables attached to other machines, or it may become tangled with itself or other items in the operating room.
What is needed, then, is an apparatus and method for keeping elongate oximeter cables in an untangled, orderly condition during use. A need also exists for an oximeter cable that is not easily separated from an oximeter/EKG machine.
However, in view of the prior art taken as a whole at the time the present invention was made, it was not obvious to those of ordinary skill how the identified needs could be fulfilled.

Apparatus for maintaining oximeter cables in orderly condition


A random number generator based on naturally occurring events in which directional randomness of radioactivity is exploited to generate a random number sequence. Radiation emissions from a radiation source are detected at different spatial locations about the radiation source. A unique numerical value is assigned to radiation detected at the different spatial locations. A random number sequence comprising numerical values is generated depending upon which spatial location radiation is detected.

Many applications of mathematical statistics in economics, cryptography, science, technology, etc., employ different kinds of long random number sequences. In some cases, the reliability of statistical analysis is directly related to the "quality of randomness" of the random numbers used.
There are several standard random distributions, such as, Poisson, Bernoulli, etc., each of which can be converted to another. These standard distributions relate to truly random processes, meaning the absence of a statistical correlation between different events or numbers no matter how close or distant from one other they are. Thus, the quality of a random number generator is defined by the proximity of its output to one of these standard truly random distributions.
Generally, random number generators fall into two large categories, algorithmic or physical. An algorithmic random number generator is based on a deterministic mathematical algorithm. The common problem with all algorithmic generators is that according to Kolmogorov's theory of complexity, to generate N truly independent random binary digits, at least 2.sup.N operations must be executed. From a practical point of view, this means that an extremely large number of operations are required even for a moderately sized random number, N. Since existing algorithmic random number generators produce long pseudorandom sequences in a matter of seconds, their complexity is relatively low, and consequently their output sequences are far from truly random. This problem cannot be solved within the framework of an algorithmic approach, and this is why the sequence produced by an algorithmic random number generator is pseudorandom rather than random. In some cases, using a pseudorandom sequence results in misleading analytical conclusions, particularly when large fluctuations of the random inputs make the decisive contribution to the final result.
This does not mean, however, that algorithmic random number generators are useless. The overwhelming advantage of mathematical random number generators compared to almost any kind of natural one is low cost and portability. Many software packages have built-in random number generating capabilities and do not require specialized hardware. The pseudorandom number sequences generated by algorithmic random number generators are suitable for certain applications. Nevertheless, there are applications which require a relatively long string of random numbers without detectable correlations. Furthermore, since an algorithmic "absolute test of randomness" is impossible by definition, the impact of the persistent long-range correlations on the statistical analysis results may become unpredictable, no matter how sophisticated the underlying algorithm is.
By contrast, a natural, or physical random number generator is based on naturally occurring random phenomena, such as thermodynamic or quantum fluctuations, radioactive decay, etc. A radioactive decay is a natural process ideally suited as a source of randomness. Each and every event of a spontaneous radioactive decay does not depend on any external conditions, such as, the quantum state of atomic electrons, presence of other atoms or electromagnetic fields, ambient chemistry, temperature, etc. In this respect, spontaneous radioactive decay is unique. Different kinds of physical random number generators including those based on radioactive decay are known in the art. However, there is room for improvement.
There are two major problems with all existing physical random number generators based on natural radioactive decay. First, the total number of unstable nuclei in a radioactive source gradually decreases in time and so does the mean radiation event frequency. Second, the Poisson time distribution of the events only applies to those ideal sources which display neither secondary radioactive decay, nor any kind of induced radiation which could be later mistaken for a primary radioactive decay. Otherwise, different events, such as the primary and the secondary radioactive decays, become related to one other and thereby correlated in time. These same problems exist in any natural random generator utilizing temporal randomness. The possible physical solution for the above two problems is to utilize a directional randomness of a natural radioactive decay, rather than the temporal randomness. The directional randomness implies that the direction of propagation of emitted radiation produced by individual events is a perfectly random characteristic of the process.
Since it is desirable to provide a random number generator that is designed to eliminate both short and long term correlations in the output, utilizing directional randomness of the physical (natural) process is an appropriate way to solve these problems of the prior art.

Random number generator based on directional randomness associated with naturally occurring random events, and method therefor


A method and system for determining the dielectric constant of a low-k dielectric film on a production substrate include measuring the electronic component of the dielectric constant using an ellipsometer, measuring the ionic component of the dielectric constant using an IR spectrometer, measuring the overall dielectric constant using a microwave spectrometer and deriving the dipolar component of the dielectric constant. The measurements and determination are non-contact and may be carried out on a production device that is further processed following the measurements.

In the semiconductor device manufacturing industry, advanced semiconductor high performance integrated circuits require that the materials used as interlayer and intermetal dielectrics decrease the RC delay of the interconnects and also reduce the crosstalk between metal lines. Low dielectric constant (low-k) materials have been developed and continue to be developed for this purpose. The particular dielectric constant of the materials used for interlayer or intermetal dielectrics is critical for device performance. It is therefore imperative to accurately measure the dielectric constant of a formed low-k dielectric film. It would be advantageous to measure the dielectric constant on a product substrate during processing, i.e., a substrate that continues to be processed and to have integrated circuits or other semiconductor devices formed thereon. It would also be advantageous to be able to measure the dielectric constant without having to form a particular structure dedicated to such measurement. Finally, it would be advantageous to measure the dielectric constant in a manner that does not damage or alter the film.
Present methods for measuring dielectric constant include use of a mercury (Hg) probe. This technique requires a specific MOS structure to be created for such measurement. Furthermore, a mercury dot contacts a surface of a low-k film producing contamination concerns for further processing. The surface contact may furthermore bring about other film quality maintenance concerns. Another method for measuring dielectric constant is the MIS (metal-insulator-semiconductor) (CAT) but this also requires a specific MOS structure for measurement and requires a formation of a metal electrode on the substrate. Yet another technique is the interdigitated comb which requires the formation of an interdigitated comb structure on the substrate. While the interdigitated comb technique produces accurate data, data collection is not real-time as the substrate being measured must be removed from production because the dielectric constant extraction requires extensive cross-sectioning and Raphael modeling. In sum, the shortcomings of conventional techniques for measuring the dielectric constant of a low-k dielectric film include surface contact, the requirement to produce a particular dedicated measurement structure, the lack of real-time data and the requirement to permanently remove the tested substrate from the production environment.
The dielectric constant is a frequency dependent, intrinsic material property. It consists of three components that result from electronic, ionic and dipolar polarization. The individual components of the overall dielectric constant are impacted by different phenomena and processees associated with semiconductor device manufacturing. It would therefore be desirable to measure or derive each of the three components as well as the overall dielectric constant.
It would therefore be ultimately desirable to provide a non-contact measurement technique that yields each of the components of the dielectric constant and the overall dielectric constant of a low-k dielectric film for a substrate that continues to be processed and which does not require formation of a particular test structure.

Measuring low dielectric constant film properties during processing

Taiwan Semiconductor Manufacturing Co., Ltd.


A method of producing metal ferrules and an apparatus therefore enable metal ferrules to be produced with high productivity and high dimensional accuracy by arranging a plurality of long-sized core wires. A jig receives a metal to be electroformed and is placed in an electroforming tank, a holding unit in which a plurality of core wire holder for holding core wires are held in circumferential array is installed in the electroforming tank, and the core wire holders and the holding unit are rotatable on their respective axes. It is preferable that the resistivity of the core wires be 5×10−6 Ωcm or less. A core wire plated within a thin layer of metal having a resistivity of 5×10−6 Ωcm or less may be used. A conductive electric discharge body may be provided on the front end of the core wire.

Ferrules are employed as a portion of the structural components of connectors used to join quartz group optical fibers. Optical connectors are designed to accurately align the positions of and connect the cores that are in the center of the optical fibers by passing optical fibers that are around 0.125 mm thick through the ferrules and securing them.
Among the ferrules that are currently in use, there are stainless steel, zirconia and plastic ones, but those made of zirconia make up the largest proportion. In producing ferrules made of zirconia, first, zirconia powder and a resin are mixed together; this is molded into a cylindrical form by means of injection molding, extrusion molding, and the like, the molded item is heated at a temperature of around 500° C.; and the resin component is decomposed and eliminated. The product is then fired at a high temperature of around 1,200° C. After firing, the product is cut to a specified length, a wire shaped diamond grinder is passed through the hole in the center of the cylinder, and precise dimensions related the inside diameter are obtained. This grinding work is carried out by hand and accuracy is demanded. In addition, boring is performed and the ferrule is finished with the polishing of the end surfaces. Furthermore, in order to improve the degree of coaxiality of the inside and the outside diameters, the processing is done using a wire centerless machine. Even though the several processes are carried out in this way, the actual state of affairs is that irregularities are produced in the inner and outside diameters, and the coaxiality and the ferrules are individually inspected and separated according to their dimensions.
High-cost injection molding equipment, extrusion molding equipment, and molds are required for the production of zirconia ferrules. In addition, such problems have been pointed out as the fact that the life of the molding equipment and molds is short, the energy cost is high due to the processing of the zirconia-resin molded items at the high temperatures of 500 to 1,200° C., the center hole must be ground with a wire shaped diamond grinder in order to produce the precise hole dimensions, and the productivity is low because the grinding work is done manually by highly skilled workers.
The present invention is one in which metal ferrules are obtained by electroforming instead of producing ferrules made of zirconia. The manufacture of fine-hole pipe by means of electroforming is already known. For example, in Japanese Patent Application Laid-open No. 11-193485, a method for manufacturing tubes having fine holes is disclosed in which a metal film is formed on the surface of a core material and the core material is removed leaving behind the metal film that has been formed. In addition, in Japanese Patent Application Laid-open No. 56-90995 and Japanese Patent Application Laid-open No. 4-311589, a method for manufacturing fine diameter pipe is disclosed in which metal is electroformed and plated on the outer surface of a core wire that can be dissolved by a chemical and, after it is cut to a specified dimension, the core wire is dissolved with the chemical and removed.
In other words, it is a method for manufacturing pipe having a fine diameter in which, after a wire core is prepared and the core wire is electroconductively processed, metal is electrodeposited around the periphery of the core wire by means of an electroforming operation and, following that, the core wire is removed with an appropriate method. Basically, by using this method, it is possible to produce ferrules for connecting optical fiber.
The diameter of the optical fiber is, in conformance with the standards, 0.125 mm and, consequently, the inside diameter of the ferrule should be around 0.126 mm. The length of the ferrule itself is 12 mm or less and the outside diameter is around 2.5 mm. There are various problems related to the production of this kind of small and fine diameter pipe by electroforming. In particular, there are the problems regarding productivity and dimensional accuracy.
In order to increase the productivity, a method is advocated in which a plurality of comparatively long core wires are used with the electroforming done at the same time and, after it is performed this way, they are cut to a specified length. When long core wires are used and, moreover, a plurality of core wires are electroformed at the same time, the problem of uniformity is especially great. Since a high degree of circularity and coaxiality is demanded of the ferrules, the thickness of the electrodeposition layer must be uniform in the longitudinal direction for each of the core wires and, at the same time, the thicknesses of the electrodeposition layers of the multiple number of core wires must be uniform.
The uniformity problems are thus related to the circularity of the ferrules, that is, the way in which the inside and outside diameters of the ferrules can be made uniform, and the coaxiality thereof, that is, in other words, the way in which the axial centers of the and the outside diameter are aligned.
For example, when a stainless steel round wire having a circular cross-section with a diameter of 0.125 mm is used as the core wire and electroforming is carried out with this connected to the power source as the cathode, as is shown in FIG. 3(b), an electroforming with a nonuniform amount of electrodeposition is obtained in which the diameter of the upper part is large and the diameter of the lower part is small. This is because the current density of the stainless steel core wire is high for the portion near the power source, but the current density becomes lower the further the area is from the power source due to the electrical resistance. Since the electrodeposition amount is proportional to the current density, the amount of electrodeposited metal becomes greater the closer the area is to the power source where the current density is high, and the amount of electrodeposited metal becomes less the further the area is from the power source. As a result, the diameter becomes larger the closer the area is to the power source, where the current density is high, and the diameter becomes smaller the further the area is from the power source.
The phenomenon of the nonuniformity of the electroforming diameter, where the outside diameter of one end of the casting becomes large and the outside diameter becomes smaller as the other end is approached, is a large problem in those cases where items small in size, such as ferrules used for optical fiber, are produced. In particular, it is a problem when a method is employed as a means to increase the ferrule productivity in which a long length of pipe is produced, and that is cut into specified lengths.
In addition, in those cases where metal balls are used as the anode, the metal balls are inserted into an electroconductive netlike tube or the like. When the core wire is electroformed, the shape of the electroforming is largely dependant upon the shape of the tube into which the metal balls have been inserted. For example, in those cases where the shape of the tube is one that bulges outward, the outside diameter of the casting becomes larger in the area that corresponds to that position and, in those cases where the outside of the tube is indented inward, the outside diameter of the corresponding portion of the casting becomes smaller.
In other words, as is shown in FIG. 13(a), the metal lumps 64 of nickel are accommodated in the metal tube 61 made of titanium. The metal tube 61 becomes narrow toward the inside in the middle area. When this metal tube 61 is employed and electroforming is carried out, the resulting casting becomes unacceptably narrow in the area that corresponds to the portion in which the metal tube is indented inward, as shown in FIG. 13(b).
Another drawback is that the factors that cause the dimensions of the electroforming to become nonuniform are dependant upon the degree of extensibility of the core wire. In other words, when the tension that is applied to the core wire is great, the core wire is stretched in the longitudinal direction and differences are produced in the diameter of the core wire. Together with this, differences are also produced in the outside diameter of the resulting casting, making it impossible to obtain a ferrule that is uniform and has a high degree of dimensional accuracy. In addition, when the tension is low, slackness is produced in the core wire, and this factor impairs the uniformity of the resulting casting in the same manner.
The present invention provides a method and an apparatus with which ferrules having a small inside diameter, uniform inside and outside diameters, and a high degree of coaxiality are produced with good efficiency and high productivity, particularly when small ferrules having an inside diameter of around 0.126 mm are produced by electroforming.

Method of producing metal ferrules, and device therefor


A method for improving bandwidth of an oscilloscope involves, in preferred embodiments, the use of frequency up-conversion and down-conversion techniques. In an illustrative embodiment the technique involves separating an input signal into a high frequency content and a low frequency content, down-converting the high frequency content in the analog domain so that it may be processed by the oscilloscope's analog front end, digitizing the low frequency content and the down-converted high frequency content, and forming a digital representation of the received analog signal from the digitized low frequency content and high frequency content.

A digital oscilloscope is a tool utilized by engineers to view signals in electronic circuitry. As circuits and signals get ever faster, it is beneficial to have digital oscilloscopes that can digitize, display and analyze these faster signals. The capability of a digital oscilloscope to digitize fast signals may be measured by its bandwidth and sample rate. The sample rate is the number of sample points taken of a waveform in a given amount of time and is inversely proportional to the sample period—the time between samples. If a sinusoidal frequency sweep is performed from DC up to higher frequencies, the bandwidth is the frequency at which the signal displayed on the digital oscilloscope screen is approximately 30% smaller than the input sine wave.
Since one of the uses of the digital oscilloscope is to design and analyze new electronic devices, high end digital oscilloscopes generally operate at speeds much higher than the present state of the art in electronics. These speeds may be achieved through the use of ever-faster sampling chips or the use of alternate methodologies to provide the desired bandwidth.
One such method involves triggering repeatedly on a periodic event. If an event is periodically repeating data obtained from multiple trigger events can be assembled together to provide a good view of the waveform. More particularly, the scope may repeatedly trigger on an event and acquire only a few points of the waveform (sometimes only one point of the waveform) on each trigger event. Scopes having this functionality are sometimes called "sampling scopes." After repeated triggers, the points are reassembled according to the sampling algorithm to create a higher "effective" sample rate version of the waveform. Furthermore, the repeated trigger events permit averaging, which can be utilized to increase the signal-to-noise ratio (SNR) and therefore enable further bandwidth increases. However, such a sampling scope presupposes a repetitive input signal so that the representation of the waveform can be generated over many triggers.
This technique may be unsuitable where the signal that is to be analyzed is not repetitive. For instance, the user of the oscilloscope may want to capture a non-repetitive event such as the cause of some failure in an electronic system. The trigger event may happen repeatedly but the signal around the trigger event may be different. Therefore, it is desirable to achieve a high bandwidth and sample rate with only a single trigger event. Such digital oscilloscopes are sometimes called real-time scopes, and acquisitions taken utilizing only a single trigger event are called single-shot acquisitions.
In real-time digital oscilloscope design the required sample rate of the sampling system is a function of the bandwidth of the analog signal to be acquired. In order to accurately represent the signal the sample rate of the sampling system should be at least twice that of the highest frequency being digitized. This is often called the "Nyquist rate."
One method for improving sample rate is time interleaving. This method utilizes multiple digitizing elements that sample the same waveform at different points in time such that the waveform resulting from combining the waveforms acquired on these multiple digitizers forms a high sample rate acquisition. For example, in a system having a two analog-to-digital converters, or ADCs, the first ADC samples the signal, then the second ADC samples the signal, then the first and so on. The digital output of the ADCs may then be multiplexed or otherwise combined to yield a composite digital corresponding to the analog input signal. Use of interleaving accordingly eases the speed requirements of each of the individual ADCs.
Use of interleaving in digital oscilloscopes may accordingly provide the significant advantage of increasing the effective bandwidth of the oscilloscope. With a given set of ADCs, a substantially higher sample rate may be achieved with the use of interleaving. Increasing the sample rate correspondingly increases the maximum frequency that may be sampled by the system, which is commonly called the "bandwidth" of the oscilloscope. The term bandwidth actually refers to a frequency range rather than an upper limit. The lower end of the range is generally understood to be around 0 Hz for an oscilloscope, so the nominal bandwidth of an oscilloscope generally corresponds to the maximum frequency that can be sampled by the system. Thus, a two-fold increase in sample rate can provide around a two-fold increase in oscilloscope bandwidth.
Where interleaving is employed the timing relationship, gain, and offset of each digitizing element is usually matched. When digitizers are mismatched in these characteristics the accuracy of the digitized waveform is compromised.
One symptom of mismatched digitizers is error signal generation. A specific type of error signal is an artifact signal created by errors in the interleaving process. One common artifact signal is a spurious tone. When multiple digitizers work in an interleaved configuration to digitize a waveform and a single tone is applied to the system, multiple tones result. The frequency location of the spurious tones is determined by the input frequency and the number of digitizers employed. The magnitude and phase of the spurious tones is determined by the input frequency magnitude and phase, as well as the response characteristics of the individual digitizers, including the response characteristics of the various signal paths leading to each digitizing element. These spurious tones serve to degrade the quality of the digitizing system, as measured with the aforementioned specifications.
These and other design issues impose practical restrictions on the degree or order of interleaving used in digital oscilloscopes. Further improvement of bandwidth in digital oscilloscopes has generally been accomplished by design and use of faster front-end amplifiers and ADCs. The performance of the amplifiers and samplers, however, is generally limited by the state of the art in integrated circuit fabrication.

High bandwidth oscilloscope for digitizing an analog signal having a bandwidth greater than the bandwidth of digitizing components of the oscilloscope


Substantial reduction or total elimination of switching transients (glitches) in an information handling system caused by inserting and/or removing hot-pluggable nodes having large power requirements is achieved with a plurality of power supplies having spare power capacity and being configurable into a main power source and an isolated power source. When insertion of a new hot-pluggable node is detected, this newly inserted node is powered from the isolated power source that is not coupled to the other existing operational nodes. When power to the new hot-pluggable node has stabilized and no longer has any detectable transients thereon, the new node is coupled to the main power source which powers the existing nodes of the information handling system. The isolated power source may thereafter be coupled to the main power source for added power supply redundancy. The new node may be detected and made part of or removed from the information handling system without being coupled to the main power source. When an operating node to be removed is detected, all processes to that node are stopped, and the node to be removed is coupled to the isolated power source. After removal of the node, the isolated power source may thereafter be coupled to the main power source for added power supply redundancy.

1. Field of the Invention
The present application is related to information handling systems, and more specifically, to information handling systems having modular hot-pluggable electronic nodes and redundant power supplies.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes, thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Mission critical information handling systems such as computer servers and associated storage disk arrays require availability twenty-four hours a day, seven days a week (24/7), without having to be shut down for maintenance, upgrading, or expansion. With high availability in mind, these information handling systems are being designed with modular subsystems, or "nodes," that may be installed and removed without turning system power off or shutting down operation thereof (hereinafter, "hot-pluggable" or "hot-plugging"). Early examples of hot-pluggable modules (nodes) are input-output cards, modems, network interface cards, disk storage units and the like. More recently, hot-pluggable processing modules such as multiple central processing units (CPUs) with or without associate cache, Redundant Array of Independent Disks (RAID) disk storage, random access memory (RAM), system expansion chassis and the like are being designed for upgrading and/or expanding the information handling systems without interrupting operation thereof. New operating systems are also being developed to take advantage of these more complex hot-pluggable nodes for information handling system upgrades, expansion and maintenance.
To realize the aforementioned benefit and potential of using hot-pluggable nodes in the information handling system, noise free power must be maintained during insertion and removal thereof. Hot-pluggable nodes such as Network Interface Cards (NICs), modems, I/O ports and the like, have limited power requirements and do not impose a large load change on the information handling system power supply. However, the newer hot-pluggable multi-processor nodes, memory nodes, disk array nodes and the like, require a great deal of power from the information handling system power supply. These high power demand hot-pluggable nodes can create switching transients on the common power bus when inserted or removed from the information handling system. The power bus is also connected to other on-line nodes, and these switching transients, if not suppressed or eliminated, may cause catastrophic glitches to other operating nodes that ultimately will cause system crashes.
Prior methods of controlling switching transients when a hot-pluggable node is inserted or removed are: ramping-up voltage gradually to the newly connected node, or breaking the ground connection before power is disconnected from the hot-pluggable node. Either of these methods worked when the node did not require a lot of power. However, the multi-processor, memory, disk array and the like nodes require orders of magnitude more current (power) than the previous less complex hot-pluggable nodes.
Therefore, a problem exists, and a solution is required for inserting or removing hot-pluggable nodes having large power requirements without creating switching transients that could disrupt operation of a mission critical, high availability information handling system. The present invention is a response to the need for accommodating hot-pluggable nodes having large power requirements without disrupting other operating nodes in the information handling system.

Hot-plugging nodes in a modular system having redundant power supplies


Devices, systems, and methods for the precise dispensation of small volumes of liquids are presented. A fluid microdispenser comprises a liquid-filled tube, an actuator coupled to the tube, and a tip at one end of the tube. When the actuator applies an actuation pressure, a precise volume of liquid is ejected from the orifice of the tip. The orifice is manufactured to control the volume of liquid ejected by each actuation and, therefore, may have a diameter smaller than that of the liquid-filled tube. The invention comprises systems, methods, and devices so that the inner diameter of the liquid-filled tube is decreased (tapered) to that of the orifice so as to maximize transmission to the orifice of the pressure generated by the actuation stimulus. This enables the volume of liquid ejected by each stimulus to be reproducibly controlled by the amplitude of the actuation stimulus.

1. Field of the Invention
This invention relates in general to the controlled dispensing of small volumes of liquid, and more particularly, to precisely metering the volume of liquid dispensed by a fluid microdispenser. Even more particularly, this invention relates to reproducibly controlling sub-nanoliter liquid drop size in a fluid microdispenser.
2. Description of the Related Art
Dispensing liquid volumes of less than 1 nanoliter accurately and reproducibly in a single drop is a long-sought goal in areas as diverse as chemical screening for drug discovery, pharmaceutical formulation, agricultural chemistry, cosmetic and food processing, and ink-jet printing. In drug discovery, for example, small quantities of chemical substances dissolved in liquid at large concentration are distributed to a large number of reaction wells each with a volume capacity of 1 μl, in which a biological assay is replicated many times. These concentrates include test chemical compounds with unknown biochemical or physiological effects in which it is desired to construct many reactions with the same concentration of the test chemical compound in each reaction.
Precise metering is also useful in analytical chemistry to distribute small quantities of concentrates of fluorimetric or radiometric indicator compounds used to measure the rate and extent of a chemical, biochemical, or physiological reaction. In cell culture, it is desired to deliver small quantities of valuable biological reagents necessary for the survival of cells or tissue explants cultured to provide a platform for biological assays. In large-format automated arrays of liquid dispensers in which the intrinsic drop volume is different from dispenser to dispenser, it is desirable to adjust the drop volume delivered by each dispenser so that all dispensers are "tuned" to deliver droplets of identical or nearly identical volume.
In all these applications, the crucial demand is delivery of sub-nanoliter liquid drops in which the volume of each drop is identical (or nearly so) and can be adjusted to the needs of the application. Many designs for dispensers have been utilized for producing sub-nanoliter-volume drops. In many circumstances, a piezoelectric actuator is coupled to a liquid filled tube that contains a circular orifice at one end from which liquid drops are ejected. When the piezoelectric material is actuated by an electrical voltage pulse, the piezoelectric material increases in thickness and compresses the liquid-filled tube by decreasing its volume. This compression induces a pressure increase in the liquid that travels throughout the interior of the tube to the liquid-vapor interface that spans the orifice at the dispensing end of the tube. If the magnitude of the pressure is sufficient to overcome the forces that limit the formation of a liquid drop, such as the interfacial tension required to increase the area of liquid surface in contact with air, the viscous drag of pressure-driven liquid movement, and the inertia inherent in causing a mass of liquid to move, then a liquid drop is ejected from the orifice. Such systems are described in U.S. Pat. No. 3,683,212 to Zoltan, U.S. Pat. No. 3,946,398 to Kyser et al, and U.S. Pat. No. 4,877,745 to Hayes et al, which are hereby incorporated herein by reference in their entirety.
These methods of liquid dispensation involve several complications. Firstly, there are several modes of drop formation. When the piezoelectric element is actuated with a voltage pulse of low amplitude, drop formation is intermittent, in that not every actuation pulse elicits ejection of a single drop. Identically sized pulses may elicit drops with different volumes. With an actuation pulse of large amplitude, a large volume of liquid may be ejected from the orifice, resulting in the formation of multiple drops for each pulse (such as satellites). These drops may have different trajectories, resulting in the possibility that some of the ejected liquid may miss its desired target. In between these small and large actuation pulse amplitudes is a range over which each pulse elicits dispensing of a single drop that is identical upon each actuation. As the pulse amplitude is increased or decreased, the volume of the ejected drop is increased or decreased in proportion. This uniform mode of dispensing is most desired when it is imperative to deliver a fixed quantity of liquid to the same location on each actuation.
A further complication with these systems is the shape of the lumen of the fluid reservoir. The choice of fluid reservoir lumen diameter is determined by many factors. These factors may include the need for a low hydraulic resistance to facilitate the movement of system fluid and sample liquid into and out of the fluid reservoir for washing as well as the expense and ability to create a lumen of desired uniform diameter and smoothness. In addition, a larger lumen will prevent obstruction by the aggregation of solid or colloidal material that may be present in the sample. The diameter of the orifice, however, is selected on the basis of the desired drop volume, which usually scales as volume−(diameter)3 (Hayes et al). Therefore, to eject drops with volumes on the order of less than 1 nl requires an orifice diameter less than 100 μm. Since lumenal diameters of the fluid reservoir may approach 1 mm or greater, there is often a mismatch in diameter of the components in the pathway along which the actuation pressure is transmitted.
The way that this mismatch is accommodated in a dispenser may determine the effectiveness of the actuation pulse. For example, in the piezo dispensers of Bogy and Talke and Zoltan, the orifice was drilled through a plate that was then cemented over one end of a 1 mm-diameter tube reservoir. These dispensers required voltage pulses across the piezoelectric elements in excess of 300 V to actuate drop ejection. Other methods to create a taper in the lumen of the tube include heating a small region of a glass tube and then drawing the tube so that the lumen narrows to the necessary orifice diameter. However, this type of heating-pulling method may result in a variable change in radius as a function of longitudinal distance down the tube as the orifice is approached, so that each drawn tube may have a different taper shape and hence, different dispensing characteristics.
The taper shape in turn influences the hydrodynamic mechanism of the pump. To form a nozzle, the tube lumen narrows and terminates as an orifice of diameter less than the diameter of the tube lumen in its straight portion. Where the tube radius begins to decrease, the fluid stream turns toward the nozzle. Restriction to flow in the longitudinal direction creates flow in the radial direction due to the buildup of a pressure gradient in the radial direction. This radial gradient of pressure has the effect of decreasing the longitudinally directed pressure gradient. If the longitudinal pressure gradient is decreased too much, then it will be insufficient to push enough liquid out the orifice to create a drop.

Method and system for precise dispensation of a liquid


A knuckle (16) for a corner assembly (10, 210, 310) wherein a cylindrical body (18) has an outboard race (39) and an inboard race (45) located therein for correspondingly receiving a first roller assembly (52) and a second roller assembly (94) carried by a wheel hub (56) such that brake engagement surfaces (12a) and (12b) on a rotor (12) are located in a parallel relationship with faces on a friction members (14a) and (14b) associated with caliper (14) and perpendicular with the axis of the wheel hub (56) to obtain a desired lateral run out relationship between the rotor (12) and the axis of the first (52) and second (94) roller assemblies retained in the wheel hub (56).

Disc brake systems are commonly use on a front axle of most vehicles because they are effective in stopping a vehicle. In such systems, a bearing assembly is fixed to a wheel hub that is bolted to a knuckle member, a brake rotor is thereafter attached to the wheel hub and a caliper that is bolted to the knuckle member spans the rotor. The knuckle member is pivotally attached to the frame of the vehicle and a caliper is bolted to the knuckle to locate first and second friction members on opposite sides of the rotor to define a corner assembly. During braking the friction members are moved into engagement with corresponding braking surfaces on the rotor to effect a brake application. Unfortunately, while the individual manufacturing tolerance of the various components that make up a corner assembly may be within desired limits when the tolerances are combined or added together a relationship may occur wherein a hub mounting surface on the wheel hub for the rotor and/or braking surface on the rotor are not in perpendicular alignment with the axis of the wheel bearing. A process has been disclosed in co-pending application Ser. No. 10/904,202 wich has been allowed and is drawn to manufacturing a modular corner assembly wherein surfaces on a wheel hub and knuckle are primarily machined in a single fixture to maintain a perpendicular relationship between the wheel hub and knuckle.

Method of manufacturing a corner assembly


An optical system comprises an imaging arrangement (1′, 1″) that transmits an image to an image plane; a sensor; and one or more locator elements that locate the imaging arrangement (1′, 1″) to provide the image on the sensor. Tolerances of the locator element(s) allow a lateral translation and a rotation of the imaging arrangement (1′; 1″) around a nominal rotation point. A parameter of the optical system is selected such that a movement, resulting from either the lateral translation or the rotation, of an optical axis (OA) on the sensor is at least partly counteracted by a movement, resulting from either the lateral translation or the rotation, of the image on the sensor with respect to the optical axis (OA). Thereby, the optical system is wholly or partly self-compensating with respect to tolerances affecting the angular position or the lateral position of the imaging arrangement.

Miniaturized camera systems are, for example, incorporated in handheld devices with imaging capability, such as barcode or text scanners, cameras, video recorders and electronic pens. Such camera systems generally include an imaging arrangement which defines an object plane and an image plane, whereby an object which is located within a field of view in the object plane is reproduced as an image in the image plane. The camera systems also include a radiation sensor which is essentially co-located with the image plane, to physically or electronically capture the image.
It may be important to precisely locate the image plane on the radiation sensor inter alia, to ascertain that the optical system produces an image of a well-defined part of the object plane. To this end, it may be necessary to keep both manufacturing and assembly tolerances of the optical system low. The absolute values of such tolerances may be very small in the case of compact imaging arrangements for handheld devices.
Assembly tolerances may be minimized by operatively engaging at least part of the imaging arrangement to the radiation sensor. For example, the imaging arrangement may include guiding surfaces that are designed to engage with corresponding surfaces on the radiation sensor to precisely locate the imaging arrangement with respect to the sensor, or vice versa. Applicant's international publication WO 03/001358 discloses an electronic pen with such an imaging arrangement. The camera system of the electronic pen is carried by a cylindrical stopper which is arranged in the front end of the pen. The imaging arrangement includes a tubular holder which contains optical components, such as one or more lenses, an aperture stop, a filter, etc. A pocket is formed at the rear end of the holder for form-fitted mounting of a two-dimensional radiation sensor, such as a CCD or CMOS sensor.
Such an optical system may require complex assembly steps in production, possibly involving manual labor. Further, the imaging arrangement has to be designed for a specific sensor geometry, resulting in a need for re-design whenever there is a change in the geometry of the sensor.

Mounting of imaging arrangements in optical systems