An audio signal switch has a plurality of inputs and an output. Each input is arranged to be selectively connected to the output via a respective transmission chain, each transmission chain includes: a first bipolar transistor, of a first type, connected to the input; a second bipolar transistor, of a second type, complementary to said first configuration, connected to the output; and an intermediate bipolar transistor, of the second type, connected between said first and second transistors. The first and second transistors are arranged in an emitter-follower circuit configuration, and the intermediate transistor is arranged to act as a diode to protect the first transistor from a large reverse voltage applied to its base-emitter junction.

1. Field of the Invention
The present invention relates to an improved audio signal switch. Audio switches are used widely in home and professional audio equipment such as amplifiers and home entertainment units.
2. Description of the Related Art
In current audio-visual (AV) systems, it is frequently desirable to be able to select one of a plurality of analog audio sources for connection to an amplifier and thence to one or more loudspeakers. Example sources include audio tape players, CD players, DVD players, video tape players, radios, mini-disc players, MP3 players, video game consoles and televisions. Many current AV systems include seven or more audio input connections.
A problem with such AV systems is the disparity in signal levels which are produced by different audio sources. For instance, the SCART specification allows audio signals to be 2rms(≡5.6Vpeak-peak), while a typical Video Analog source is only a maximum of 1.4Vpeak-peak.
Prior art solutions include use of a CMOS switch, i.e., a standard CMOS transmission gate including NMOS and PMOS transistors arranged in parallel. This configuration is limited in that the MOS operating voltage needs to be higher than the signal amplitude to be switched, thus limiting this solution to cases where the amplitude of the signal(s) to be switched does not exceed the value of VDD, which is typically 5V.
In order to overcome the problem of the above described arrangement, certain systems employ selective matched attenuation and amplification. The incoming analog signal is attenuated by a pre-determined amount pre-switching, and then selectively amplified post-switching to re-create the original level of the signal. This allows the signal which is actually switched to be within the operating range of the CMOS devices. However, aside from the extra components introduced by such a scheme, errors will be introduced by the signal dividers used, which are commonly resistors. Typical devices will introduce a 1% error due to component value mismatch. This error is introduced into both AC and DC values. The AC error does not generally matter, but the DC error will be different for each source and thus creates a signal discontinuity which presents itself as an audible commutation 'pop' upon switching. Such a 'pop' is not generally acceptable and requires further additional processing, such as offset cancellation and smoothing, to rectify the situation.
A solution to this problem uses bipolar transistors arranged in an emitter follower configuration. Since such devices do not use the gate of CMOS components, which is the main voltage limitation of sub-micron MOS devices, it is possible to use relatively high-voltage bipolar components in a sub-micron BiCMOS process.
FIG. 1 shows such a prior art attempt to solve the problem of audio source switching. The circuit is arranged to switch between two input audio sources 100, 105. Although only two input sources are shown for clarity, the skilled person will realize that appropriate modifications may be made to allow for switching between any number of input audio sources.
The input sources 100, 105 are connected to the base of respective transistors 125, 120. The collector of each transistor is connected to a voltage supply Vcc. The emitter of each transistor is connected to one terminal of a respective current source 110, 115. The other terminal of the current source is connected to a ground potential.
The emitter of each transistor 125, 120 is further connected to the base of a further respective transistor 140, 145. In addition to said connections between said emitter of transistors 125, 120 and said bases of said transistors 140, 145, there is a switch arrangement 130 which is operable to selectively connect said intermediate connection to Vcc. In the case of more than two input sources, the switch is arranged to selectively connect all unwanted inputs to Vcc. Whichever connection is selected by said switch dictates which input audio source 100, 105 is presented at the output 150 of the switch circuit.
The emitters of transistors 140, 145 are connected together to a first terminal of a current source 135. The other terminal of current source 135 is connected to Vcc. The collectors of transistors 140, 145 are connected to a ground potential. The Emitters of transistors 140, 145 are connected together to the output port 150.
Transistors 125, 120 are NPN (vertical structure), and in conjunction with current sources 110, 115 either transistor 125, 120 will operate as an emitter follower depending on the status of switch 130. The switch 130 ensures that the inoperative transistor remains inactive. Either one of transistors 140, 145 in conjunction with current source 135 also operate as an emitter follower, depending which transistor is active, which is again controlled by switch 130.
The inputs 100, 105 are configured to share a common biasing system so that there is a minimal DC offset between the inputs. The input signal is generally AC-linked.
In FIG. 1, with the switch in the position shown, input 105 is selected. The position of the switch has the effect of shorting the emitter of transistor 125 and the base of transistor 140 to Vcc, thus disabling input 100.
A problem with the circuit of FIG. 1 is that the vertical bipolar transistor structure is not able to accept a very high reverse voltage for the emitter-base junction, unlike the base-collector junction—the maximum VEB is lower than the maximum VCB. This means that the amplitude of the switched signal is limited, and renders the circuit of FIG. 1 unsuitable for analog audio signal amplitudes.
In an attempt to remedy the problems with the circuit of FIG. 1, the circuit of FIG. 2 has been proposed. It has the same basic structure as the circuit of FIG. 1, and similar reference numerals refer to similar components. It differs to the circuit of FIG. 1 in that there is a diode 255, 260 connected between the base and emitter of transistors 225 and 220 respectively. The effect of the diodes 255, 260 is to limit the reverse biasing of the transistors 225, 220, VBE to −Vd, where Vd is equal to the diode voltage drop.
However, this solution introduces a new problem in that the non-selected input 200 sees its voltage shifted by diode 255 to (Vcc−Vd). That has the effect that if the non-selected input is selected by switch 230, there will be a perturbation of the signal during restoration of the DC level, with additional current flowing from the forward biased diode. This perturbation occurs during signal selection and has an adverse effect on audio signal quality.
Therefore, there is a specific problem with the amplitude levels of audio signals in that they exist over a wide range, and this problem is further exacerbated by problems introduced by the trend towards reduced operating voltages for integrated circuits, which makes it problematic to interface with signals at levels in excess of supply voltage.
The circuits of FIGS. 1 and 2 address some of the problems of earlier prior art solutions, but also introduce problems of their own.

STMicroelectronics Asia Pacific Pte Ltd.


Oxygen-scavenging polyester compositions are disclosed that comprise one or more polyesters having incorporated therein residues of 3-hexenedioic acid and terephthalic acid. The compositions may further comprise residues of one or more aliphatic dicarboxylic acids such as adipic acid. One or more of the polyesters of the compositions may comprise significant amounts of repeating units of polyethylene terephthalate as homopolymers or copolymers, making them suitable for us in packaging compositions having oxygen-scavenging properties.

Many food and beverage products are sensitive to oxygen and suffer significant deterioration upon exposure to even very low levels of oxygen. Limiting the exposure of such oxygen-sensitive articles to oxygen maintains the quality and improves the shelf life of these articles. By limiting the oxygen exposure of oxygen-sensitive food articles in the packaging system, the quality of the food articles is maintained and spoilage is reduced. Such packaging thus keeps the article in inventory longer, thereby reducing restocking costs, and costs incurred from waste.
Polyester polymers, and especially polyethylene terephthalate (PET) homopolymers and copolymers, are commonly used in packaging applications. PET has a number of valuable properties for packaging but lacks sufficient gas barrier for some applications, limiting its use in packaging for oxygen-sensitive products such as beer, fruit juices, citrus products, tomato-based products, and aseptically packed meat. Multilayer structures have been proposed in order to improve PET's gas barrier. Polymers that have excellent oxygen barrier (passive barrier) or scavenging properties (active barrier) may be combined with PET to produce a layered structure consisting of the individual polymers. Blends of barrier polymers with PET have also been used to improve the oxygen barrier of packages.
m-Xylylene diamine adipate, a polyamide consisting of repeating units derived from m-xylylene diamine and adipic acid, can be blended with PET to provide packaging that is somewhat resistant to encroachment of oxygen. Transition metal salts, such as cobalt salts, can be added to the polyamide, or blends of PET and the polyamide, to catalyze and actively promote the oxidation of the polyamide polymer, thereby further enhancing the oxygen barrier characteristics of the package. The use of active oxygen scavengers, which chemically remove oxygen migrating through the walls of the package, can be a very effective method to reduce the oxygen transmission rates of plastics used in packaging. However, a drawback associated with its use is that an extended "induction time" is often present before full scavenging activity is achieved. This deficiency may be partially addressed by increasing the level of the polyamide in the packaging. However, this may increase the cost of the final package, and may produce undesirable effects on the appearance of the package, such as adding haze or unwanted color. Increasing the concentration of such oxygen scavengers may also complicate manufacture and recycling of the package.
U.S. Pat. No. 2,388,318 discloses unsaturated polyesters comprised of dicarboxylic acids containing unsaturated carbon-to-carbon bonds which are not conjugated with other unsaturated carbon-to-carbon bonds or with the carbon-to-oxygen double bonds of a carboxyl group, for example dihydromuconic acid. The polyesters are prepared with a slight excess of a saturated glycol, and optionally with a saturated dicarboxylic acid.
JP 46043262 discloses a fiber molded from polyester in which at least 80% of the repeating structural units are ethylene terephthalate, and which has carbon-carbon unsaturated bonds. A compound having unsaturated bonds is used in an amount of 0.5-10 mole % with respect to the repeating units of the polyester. These modified polyesters are then grafted to improve the dyeability, pilling resistance, and antistatic properties of the fiber.
U.S. Pat. No. 4,299,927 discloses polymer compositions that comprise from about 75 to about 99% by weight of the reaction product of (a) from about 50 to about 90% by weight, based on the weight of the reaction product, of an ethylenically unsaturated polyester derived from an α,β-ethylenically unsaturated dicarboxylic acid with a saturated aliphatic polyol, and (b) from about 50 to about 10% by weight, based on the weight of the reaction product, of a modified polyolefin derived from an α,β-ethylenically unsaturated dicarboxylic acid anhydride and a polyolefin.
U.S. Pat. No. 5,399,289 discloses compositions for scavenging oxygen that comprise an ethylenically unsaturated hydrocarbon polymer which has 0.01-1.0 equivalents of carbon-carbon double bonds per 100 g of polymer and a transition metal catalyst and can be incorporated into various types of layers.
U.S. Pat. No. 5,639,815 discloses a wall for a package that includes a layer that includes a polymer and is capable of scavenging oxygen through the metal-catalyzed oxidation of an oxidizable organic component thereof. The oxidizable organic component is preferably itself a polymer, and may be the only polymer in the composition. Preferred compositions include a blend of 96% polyethylene terephthalate and 4% poly (m-xylyleneadipamide) containing 200 ppm cobalt as catalyst, which is said to have good permeance-versus-time performance when formed into a bottle.
U.S. Pat. No. 5,859,145 discloses a process for esterifying and/or transesterifying a polymer having a polyethylenic backbone and pendant acid and/or ester moieties, the process comprising contacting a melt of the polymer with a transesterifying compound so that the polymer undergoes esterification and/or transesterification but not alcoholysis. The esterified or transesterified polymer also has pendant ester moieties which differ in kind and/or number from the unreacted polymer. The process may include adding an amount of a transition metal salt that is effective to promote oxygen scavenging. Also disclosed are compositions that include a component comprising an ethylenic or polyethylenic backbone and a pendant or terminal moiety comprising a benzylic, allylic, or ether-containing radical.
U.S. Pat. No. 6,083,585 discloses compositions that include condensation copolymers comprising predominantly polyester segments and an oxygen scavenging amount of polyolefin oligomer segments. The polyester segments comprise segments derived from typical bottling and packaging polyesters such as PET and PEN. The copolymers are preferably formed by transesterification during reactive extrusion and typically comprise about 0.5 to about 12 wt % of polyolefin oligomer segments.
U.S. Pat. No. 6,780,916 discloses a resin composition that provides good optical properties when stretched, and efficient oxygen-scavenging, the resin composition comprising a film-forming polyester and an effective amount of oxygen-scavenging particles having a particle size distribution such that particles of less than about 25 microns in size do not exceed a concentration defined by a formula that includes the apparent density of the particles. Suitable diols for use in the polymers described are said to include 1,4-butenediol.
There remains a need in the art for polyester compositions having oxygen-scavenging properties, and especially those comprising substantial amounts of terephthalic acid, making them suitable for use in packaging applications.

Oxygen-scavenging polyester compositions useful in packaging


An optical waveguide including a core having silica, Al, a non-fluorescent rare-earth ion, Ge, Er, and Tm. The non-fluorescent rare-earth ion may be La. Exemplary compositions concentrations are Er is from 15 ppm to 3000 ppm, Al is from 0.5 mol % to 12 mol %, La is less than or equal to 2 mol %, Tm is from 15 ppm to 10,000 ppm; and the Ge is less than or equal to 15 mol %. The core may further include F. An exemplary concentration of F is less than or equal to 6 anion mol %.

The present case is related to co-pending, commonly owned, concurrently filed U.S. Applications entitled xe2x80x9cImproved Emission Silicate Waveguide Compositions For Extended L-Band and S-band Amplificationxe2x80x9d and xe2x80x9cGermanium Free Silicate Waveguide Compositions For Extended L-Band and S-Band Amplificationxe2x80x9d, both of which are hereby incorporated by reference.
The present invention relates to an optical waveguide suitable for optical amplification at wavelengths in the extended L- and S-bands. In particular, the present invention relates to waveguides having a chemical composition that provides for longer excited-state lifetime and enhanced infrared emission.
High-speed optical telecommunications via optical networks allow for the transfer of extremely large amounts of information through optical signals. As these optical signals travel over long distances or are coupled, manipulated, or directed by optical devices, the signals lose their strength. Signal attenuation may be caused by a number of factors, such as the intrinsic absorption and scattering in the transmission fiber, coupling losses, and bending losses. As a signal becomes weaker, it becomes more difficult to detect and propagate the signal. Eventually, a signal may become so weak that the information is lost.
Optical amplification is a technology that intensifies an optical signal. Optical amplification is a vital part of present-day high-speed optical communications.
Optical amplification is typically performed using devices (amplifiers) that contain a pump laser, a wavelength division multiplexer, isolators, gain shaping gratings, and an active rare-earth-doped optical fiber. The typical wavelength range at which present day optical networksxe2x80x94and optical amplifiersxe2x80x94operate is xcx9c1530-1570 nm, the so-called C-band. A band may be defined as a range of wavelengths, i.e., an operating envelope, within which the optical signals may be handled. A greater number of available bands generally translates into more available communication channels. The more channels, the more information may be transmitted.
Each band is identified with a letter denomination. Band denominations used in the present application are:
Currently, high-speed internet-backbone optical fiber networks rely on optical amplifiers to provide signal enhancement about every 40-100 km. State-of-the-art commercial systems rely on dense wavelength division multiplexing (DWDM) to transmit xcx9c80xe2x88x9210 Gbit/second channels within a narrow wavelength band (e.g. C-band). Channels can be spaced xcx9c0.4 nm apart. These channels can be interleaved with forward and backward transmission (0.4 nm between a forward and backward directed channel) to provide multiterabit/second bidirectional transmission rates over a single fiber.
Recently, with the advent of L-band amplifiers, the optical transmission operating range has been extended from 1530-1565 nm to 1530-1605 nmxe2x80x94using both C- and L-band amplifiers, which provides up to 160 channels/fiber. There is a significant desire for even broader band operation to increase information throughput. Normally operation is limited to a maximum wavelength of xcx9c1605 nm by excited state absorption in the erbium-doped fiber. Operation is theoretically limited to wavelengths of light shorter than xcx9c1650 nm in silicate-based fibers owing to high attenuation from multiphonon absorption at wavelengths greater than 1650 nm. Currently, operation is practically limited to wavelengths shorter than xcx9c1630 nm in a fiber system owing to macrobending losses.
Future systems will potentially use wavelengths from 1450 to 1630 nm, which includes the so-called S-band. Use of the S-band has been demonstrated to nearly double the information carrying capacity of existing two stage C-+L-band systems. Transmissions of up to xcx9c10.5 Tb/s over a single fiber using a C-+L-+S-band configuration have been shown in a laboratory demonstration.
There are generally three approaches to optical amplification in the 1450-1630 nm region; Raman amplification, amplification with rare-earth-doped fiber amplifiers, and amplification that combines Raman and rare-earth-doped components.
Raman Fiber Amplifiers
Raman amplifiers rely on the combination of input photons with lattice vibration (phonons) to shift the pump light to longer wavelengths (Stokes shift). Amplification spectra are broad, but sometimes have unwanted sharp peaks. The process is inefficient, and requires a high power pump source. Such high power pumps include fiber lasers or a series of laser diodes, which can be quite costly. The process is nonlinear with incident intensity. Because it requires high input intensities, the process may lead to other unwanted nonlinear processes such as 4-wave mixing and self phase modulation. Nonetheless, Raman amplifiers are useful in combination with rare-earth-doped amplifiers to increase span lengths, especially for 10 Gbit/s and faster systems operating in the C- and L-bands.
Rare-Earth-Doped Fiber Amplifiers
Rare-earth doped amplifiers rely on excitation of electrons in rare-earth ions by an optical pump and subsequent emission of light as the excited ions relax back to a lower energy state. Excited electrons can relax by two processes: spontaneous emission and stimulated emission. The former leads to unwanted noise and the latter provides amplification. Critical parameters for an amplifier are its spectral breadth, noise figure, and power conversion efficiency (PCE). The latter two parameters correlate with excited state lifetime of the rare-earth ions: longer lifetimes lead to lower noise and higher PCEs. Spectral breadth in the fiber in the C-band, which determines how many channels can be simultaneously amplified in the C-band, correlates with the full-width-half-maximum (FWHM) of the spontaneous emission spectrum of the rare-earth-doped glass.
The majority of commercial amplifiers are based on fibers in which the core glass comprises erbium-doped silicates that contain either aluminum and lanthanum (SALExe2x80x94(silicon, aluminum, lanthanum, erbium)) or aluminum and germanium (SAGE). Of the two traditional fiber types, SAGE provides slightly greater spectral width, which allows for additional channels. SALE fiber generally provides slightly higher solubility of rare earth ions, which enables shorter fibers to be used. This is advantageous to minimize, for example, polarization mode dispersion. SALE and SAGE fibers typically provide amplification in the C- or L-bands, but this leaves a large portion of the low-loss region of the silica transmission fiber unused, namely the S-band and long wavelength portion of the extended L-band region ( greater than 1610 nm).
In the S-band, rare-earth doped fiber amplifiers typically rely on non-silicate thulium (Tm)-doped glasses. Thulium provides a relatively broad emission that is centered at xcx9c1470 nm. The energy levels of thulium are such that multiphonon processes can easily quench this transition, especially in high phonon energy hosts such as silica. For this reason, lower phonon energy glasses such as heavy metal oxides (e.g. germanosilicates) and especially fluoride glasses such as xe2x80x9cZBLANxe2x80x9d are preferred as hosts for the thulium. These non-silicate glasses tend to be difficult to fiberize and splice to existing transmission fiber and to date have limited commercial applications.
In the extended L-band, rare earth doped fibers typically are heavy-metal oxide or fluoride-based. Examples of oxide glasses are those based on tellurium oxide and antimony oxide. Both of these types of glasses are difficult to splice owing to their low melting points and high refractive indices.
In the S- and extended L-band, researchers have worked on an optical amplifier approach using a fiber with a core containing simultaneously erbium and thulium. Unexamined Korean Patent Application; No. 10-1998-00460125 mentions a fiber having a core comprising SiO2, P2O5, Al2O3, GeO2, Er2O3, Tm2O3 (SPAGET). The Er and Tm ions are in the range of 100-3000 ppm and the core can optionally contain Yb, Ho, Pr, and Tb in addition to Er and Tm. The reference further speaks about a cladding that contains SiO2, F, P2O5, and B2O3.
An Erxe2x80x94Tm codoped silica fiber laser has been reported. The laser contained a fiber having a SiO2xe2x80x94Al2O3xe2x80x94GeO2xe2x80x94Er2O3xe2x80x94Tm2O3 core (SAGET) and was pumped at 945-995 nm to obtain emission from Er (xcx9c1.55 xcexcm), Tm (xcx9c1.85-1.96 xcexcm) or both depending upon the parameters of mirrors in the laser cavity, fiber length, pump rate, and pump wavelength. Two fibers were reported. In the first fiber the Er/Tm concentrations were 6000/600 ppm. In the second the concentrations were 1200/6000 ppm. The numerical apertures (NAs) were xcx9c0.27 and xcx9c0.12, respectively. The second mode cutoff was xcx9c1.4 xcexcm in both. The first fiber exhibited lasing (gain), but the second did not.
An amplified spontaneous emission (ASE) light source has been reported that contains Er and Tm and which exhibits significant emission enhancement in the S-band region compared to sources that contain erbium only. The reported fiber contained an SiO2xe2x80x94Al2O3xe2x80x94GeO2xe2x80x94Er2O3xe2x80x94Tm2O3 core (SAGET) and contained two levels of Er/Tm. In the first fiber the Er/Tm concentrations were 1200/6000 ppm. In the second the concentrations were 300/600 ppm. The NAs of the fibers were 0.2 and 0.22 respectively. In both cases an xcx9c90 nm FWHM forward ASE peak was observed from xcx9c1460-1550 nm. The second fiber had an ASE about 5 dB higher than the first.
Finally, L-band amplifier modules have been reported that contain two separate fiber types, one doped only with erbium and one doped only with thulium-doped. The fibers are coupled together. The thulium-doped fiber absorbs a portion of the light emitted from the erbium-doped fiber and modifies the gain slope.
Given the ever increasing demand for broadband services, it is highly desirable to have a single amplifier, compatible with silicate transmission fiber, that has significant gain at wavelengths between 1570 and xcx9c1630 nm, i.e., extended L-band. An extended L-band amplifier operating to xcx9c1630 nm would enable greater than 50% more channels compared to a conventional L-band amplifier. Thus, there is a desire for silicate-based fibers that provide substantial emission in the extended L-band. It is also desirable to have an economical, S-band amplifier that is compatible with the current fiber infrastructure. A desirable fiber amplifier would provide longer lifetime and/or increased emission intensity compared to existing amplifiers along the desired bands.
The present invention is directed to extended L-band amplifiers, and to waveguides and glasses for use in such amplifiers. The present invention further provides desirable S-band emission in a silica-based waveguides and amplifiers.
An optical waveguide according to the present invention comprises a core and a cladding surrounding the core. The cladding comprises a material having a lower refractive index than the core at the operating wavelength of the waveguide. The optical waveguide may be, for example, a laser rod, an optical fiber, or a planar waveguide.
The core comprises silica, Al, a non-fluorescent rare-earth ion, Ge, Er, and Tm. An exemplary non-fluorescent rare-earth ion is La. However, other the non-fluorescent rare-earth ion such as Y, Sc, and Lu also are contemplated.
In exemplary compositions the molar concentrations are: Er from 15 ppm to 3000 ppm, Al from 0.5 mol % to 12 mol %, La less than or equal to 2 mol %, Tm from 15 ppm to 10,000 ppm; and the Ge less than or equal to 15 mol %. The core may further include F. An exemplary concentration of F is less than or equal to 6 anion mol %. In particular embodiments, the concentration of Er is from 150 ppm to 1500 ppm, the concentration of Al is from 4 mol % to 10 mol %, the concentration of Tm is from 150 ppm to 3000 ppm, and/or the concentration of Ge is from 1 mol % to 15 mol %.
In more particular embodiments, the concentration of Al is greater than 1 mol %. The concentration of Al plus Ge plus La may be greater than 5 mol % or 10 mol %. The exemplary concentration of Tm may be greater than 300 ppm or greater than 1000 ppm. In some embodiments, the concentration ratio of Tm/Er is at least 1.
The optical waveguide may have desirable spontaneous emission intensities. Exemplary values are: emission at 1600 nm when pumped at 980 nm of greater than or equal to xe2x88x928 dB relative to the maximum emission intensity at xcx9c1.53 xcexcm; emission at 1650 nm when pumped at 980 nm greater than or equal to xe2x88x9214 dB relative to the maximum emission intensity at xcx9c1.53 xcexcm; emission at 1500 nm when pumped at 980 nm is no less than xe2x88x9210 dB relative to the maximum emission intensity at xcx9c1.53 xcexcm; emission at 1500 nm when pumped at 800 nm is no less than xe2x88x928 dB relative to the maximum emission intensity at xcx9c1.53 xcexcm; and emission at 1500 nm when pumped at 1060 nm is no less than xe2x88x9210 dB relative to the maximum emission intensity at xcx9c1.53 xcexcm.
The average Er3+4I13/2 lifetime of the waveguide may be greater than 1 ms, or preferably greater than 5 ms. The present invention also contemplates optical devices, such as an amplifying device, using the disclosed optical waveguide.
A method of making an erbium-doped optical fiber for use in optical amplifiers according to the present invention comprises the step of providing a substrate tube. High purity silica-based cladding layers are deposited on the inside of the tube. A core glass that comprises silica, Al, a non-fluorescent rare-earth ion, Ge, Er, and Tm is then deposited in the tube. The tube is then collapsed to form a preform. Finally, the preform is drawn to yield optical fiber.
In certain embodiments, the core glass is substantially homogeneous. The core may include at least two regions, wherein one region contains a substantially different Er to Tm ratio than the other region. Said regions may be in an annular arrangement.
The core of such a waveguide may be made with one or more MCVD passes, sol-gel passes or with soot deposition, solution doping, and consolidation passes.

Silicate waveguide compositions for extended L-band and S-band amplification


This disclosure describes a novel population of cerebellum-derived neural stem cells that can be isolated from the adult brain, expanded, and differentiated into neurons, astrocytes and oligodendrocytes. This disclosure also describes compositions and methods for producing oligodendrocytes. Oligodendrocytes can be produced in vitro (e.g., in culture) or in vivo (e.g., for therapy or in a non-human transgenic animal) using the compositions and methods described herein.

Reports of cerebellar neural stem cells (NSCs) came initially from studies of postnatal day 7 (neurogenic) brain (Kornack et al., 2001, Science, 294:2127-2130); the source was suggested to be scattered prominin1+ cells in the white matter. Klein et al. (2005, Develop., 132:4497-508) described cells derived from cerebellum capable of forming neurospheres with stage-restricted multilineage differentiation capacity.
Much attention is focused on developing therapies to promote oligodendrocyte differentiation or to transplant oligodendrocytes or oligodendrocyte progenitors to remyelinate damaged areas and restore function in the central nervous system. NSCs can be isolated from fetal or adult brain and can act as a source of myelinating transplants but, for greatest efficacy, these cells must first be directed to the oligodendrocyte progenitor (OP) pathway. Currently, there are limited methods for stimulating the production of oligodendrocytes. For example, there are reports in the literature that retinoic acid can induce embryonic stem cells to differentiate into oligodendrocytes, that gamma-secretase can direct cells down the OP pathway, and that ciliary neurotrophic factor (CNTF) appears to be involved in the maturation of oligodendrocytes, which results in an increase in myelin formation.

Adult cerebellum-derived neural stem cells and compositions and methods for producing oligodendrocytes


A cart for connecting or attaching to a wheelchair is provided to assist a wheelchair user to more easily collect and move items, such as groceries. In certain embodiments the cart is further defined as a shopping cart.

Currently, handicapped shoppers are provided with few options when it comes to shopping in most stores: ask an employee to help them out of their personal wheelchair into a generic store owned wheelchair that has a small basket welded on; place a small unstable plastic hand basket on their lap; or have assistance from an employee pushing around a cart, accompanying the individual while they shop. Whenever the handicapped shopper needs an item that is out of their reach, the shopper either need to apply excessive strain and creativity to get the item or ask someone for help. Grocery stores have hundreds of handicapped customers who lack the freedom of shopping independently. Therefore, the need for a product that will ease such tasks for handicapped shoppers.

Cart adapted for connection to a wheelchair


A frame structure of a backlight module includes a body and a mold frame. A side wall surrounds a bearing surface of the body, and the side wall has at least one stopper and at least one positioning hole. A side edge of the mold frame has at least one positioning post. When the mold frame is disposed on the side wall, the side edge of the mold frame leans against the stopper, and the positioning post of the mold frame is embedded in the positioning hole.

1. Field of the Invention
The present invention relates to a frame structure, and more particularly to a frame structure of a backlight module.
2. Related Art
With the fast development of electronics technology, currently, various forms of electronic products are developed towards a diversified design trend, and the development and the design of electronic products being light, thin, short, and small become a mainstream on the market. The Liquid Crystal Display (LCD) is equipped with advantages being light and thin, power-saving, and radiation free, so currently, the LCD is greatly applied to various electronic products, such as a notebook computer, a Personal Digital Assistant (PDA), a digital camera, a camcorder, a mobile phone, and a handheld game machine, so that the electronic products achieve the light weight demand.
The LCD is mainly formed by a backlight module, a rear bezel, a Liquid Crystal Module (LCM), and an iron bezel. During assembly of the LCD, firstly the backlight module is disposed in the rear bezel. The backlight module is formed by a light guiding plate, a reflecting plate, a backlight source, and a backlight source holder. The light guiding plate is arranged above the reflecting plate, the backlight source holder is arranged on a side edge of the light guiding plate, and the backlight source is arranged in the backlight source holder. Then, the LCM is arranged above the backlight module, and leans against the rear bezel. Next, the rear bezel and the LCM are wrapped with the iron bezel, so as to complete the assembly operation of the LCD.
A mold frame is additionally disposed between the rear bezel and the LCM, so that when the LCM leans against the rear bezel, a proper pitch may be maintained between an optical film arranged on the LCM and the light guiding plate of the backlight module. However, for arrangement of the mold frame, generally, a binding material, such as an adhesive agent or a double-sided adhesive tape, is coated on or adhered to the rear bezel, then a side edge of the mold frame is aligned with a side edge of the rear bezel, and the mold frame is pressed on and adhered to the rear bezel, so that the mold frame is firmly bound with the rear bezel, thus, the optical film of the LCM is disposed on the mold frame.
However, during an operation process in which the mold frame is disposed on the rear bezel, contact surfaces of the mold frame and the rear bezel are flattened surfaces, so the no positioning mechanism exists between the mold frame and the rear bezel. When an operator performs an assembly operation between the mold frame and the rear bezel, generally the operator aligns a side edge of the mold frame with an edge of the rear bezel in a naked eye positioning manner, and then the mold frame is adhered to the rear bezel. Therefore, frequently, due to an improper operation of the operator, the mold frame is skew on the rear bezel, and a product yield after the assembly is lowered. Further, in order to precisely and alignedly adhere the mold frame to the rear bezel, the operator must spend quite a long time in positioning the mold frame and the rear bezel, so that problems of low performances and an increased cost of the assembly production exist.


The present disclosure discloses a control method and a control apparatus for brightness of display panel, a storage medium and a processor. The method comprises: acquiring a plurality of pixel values processed by an image processor, wherein the bit width of each of the plurality of pixel values is a first preset bit width; performing data type conversion on each pixel value to obtain a plurality of pixel values of a second preset bit width, wherein the second preset bit width is greater than the first preset bit width; sending the plurality of pixel values of the second preset bit width to a digital-to-analog conversion module to determine the voltage output value of each sub-pixel of a display panel, wherein the voltage output value has a first linear relationship with the screen brightness of the display panel; and adjusting the voltage output value to control the screen brightness of the display panel.

in the related art, the display panel often has uneven brightness, causing various display traces, i.e., Mura phenomenon. There are many reasons for the phenomenon, one of which is inconsistent attenuation of an input signal caused by a circuit layout process in the display panel, thereby leading to differences in display brightness. If you want to eliminate Mura, the current way is generally to adjust the display brightness by adjusting the display grayscale value to achieve the effect of uniform display brightness of the display panel. However, when the grayscale compensation voltage is adjusted in this way, the compensation voltage value is often wrong due to inaccurate calculation of the grayscale value and a large number of values. As a result, the display brightness will be uneven and the accuracy of the brightness compensation will be insufficient, so that when a user watches content displayed on the display panel, the user often experiences increased fatigue, which in turn reduces the user's interest in using the display panel.
In view of the problems above, no effective solution has been proposed.

Control method and control apparatus for brightness of display panel, storage medium and processor


The invention relates to a roller hearth furnace (1) for heating and/or temperature equilibration of continuous cast products (2), comprising a first series of rollers (13) running in the longitudinal direction (12) and a second parallel series of rollers (15) on the outlet side (14), wherein a buffer zone (16) with lifting elements (17) for the perpendicular transport of the continuous cast product (2) is arranged between the series of rollers (13, 15). Furthermore, alternative arrangements for a further process route (28) are provided.

The invention concerns a roller hearth furnace for heating and/or temperature equalization of continuously cast products, especially those made of steel or steel materials, which are cut to lengths that fit the furnace and are then conveyed into and out of the furnace through the furnace chamber on rollers, and a method for using the roller hearth furnace upstream of a hot strip finishing train, in which the hot strip is subjected, among other operations, to rolling, cooling, and coiling into coils in a coiling station.
Roller hearth furnaces of this type are very long and are associated with thermal losses. In addition, due to the long time the continuously cast products lie on the rollers, these roller hearth furnaces cause impressions on the underside of the products as a result of scale caked on the product, and this later leads, during the rolling process, to reduced quality of the rolled product, especially rolled strip.
A roller hearth furnace of this type installed upstream of a hot strip finishing train is described, for example, in DE 44 11 216 A1. This furnace has stationary and traveling hearths, on whose refractory lining the pieces of material to be heated are laid. Sloping depressions are incorporated in the refractory lining to cause the pieces of material to be heated from below and to help remove scale. The scale is removed through travel grooves between the hearths and through scale drop shafts.
In the case of hearths formed by rollers, although the removal of scale is more favorable when the spaces between the rollers are short, residual pieces of scale are pressed into the strand material by the weight of heavy continuously cast products, such as cut lengths of slab, and cause the aforementioned surface defects, which, as described above, persist in the finished product. A traveling hearth equipped with rollers is disclosed, for example, by EP 0 361 057 B1. However, a design of this type results in an extremely complicated structure as a roller hearth and traveling hearth system comprising conveying rollers, which are supported outside the furnace chamber and can be moved into and out of spaces of the traveling hearth through openings in the side walls of the furnace. This results in large heat losses and low thermal efficiency.
Roller hearth furnaces for heating and/or temperature equalization of continuously cast products are known from the documents IT 1 236 130 B, EP 0 264 459 A1, EP 0 353 487 A1, WO 94/18 514 A and DE 35 25 457 A1. These roller hearth furnaces do not allow any change in the thermal efficiency.

Roller hearth furnace for healing and/or temperature equalisation of steel or steel alloy continuous cast products and arrangement thereof before a hot strip final rolling mill


Technologies are presented for providing a suggestion list presenting options for posting information related to viewed content on a communication network. In some examples, a user may desire to contribute to posted content by adding comments and other relevant information. A system may identify one or more key terms included in the viewed content, and may compare the key terms with content, such as files, emails, websites, images and media content, on computing devices and web browser histories associated with the user to identify information that may be related to the viewed content. If the system identifies information related to the key terms of the viewed content, the system may present the identified information associated with key terms to the user, and may enable selection from a posting suggestion list for automatically posting.

Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
In a communication environment, users may view and share information over a communication network such as social and professional networks, blogs and other media sharing networks. Users may post content such as status updates, comments, pictures, videos, articles, and other content, and subscribing users may contribute to posted content by posting additional comments, pictures, and other information related to the posted content. Typically, when a user desires to contributed to posted content, the user needs to manually generate the content for posting, and if the user wants to add a link or attachment to additional information, the user may have to manually locate the information and add the attachment to the posted content. Manually locating and generating content for posting in response to posted content on the communication network may be time consuming for the user, and may also be inconvenient if the user is unable to remember where relevant information is stored and is unable to quickly locate the material desired for posting in response to the viewed content.

This patent is subject to a terminal disclaimer.

Content suggestion for posting on communication network


A fender liner includes a surface layer serving as the outermost layer and an inner layer located between the surface layer and the outer surface of a wheel well. The surface layer and the inner layer are formed of nonwoven fabric. The nonwoven fabric forming the inner layer has a higher tensile strength than that of the nonwoven fabric forming the surface layer. Accordingly, the fender liner has a favorable noise reduction capability, and has a sufficient rigidity to bear a weight increase due to water absorption. Alternatively, the nonwoven fabric forming the surface layer may have a higher bulk specific gravity and a smaller fiber diameter than those of the nonwoven fabric forming the inner layer. In this case, the noise reduction capability and the durability are both improved.

The present invention relates to an exterior component attached to a lower part of a vehicle body, such as a fender liner and an under protector that are attached to the lower part of the exterior of vehicle body.
Generally, exterior components such as fender liners and under protectors cover are attached to the lower part of a vehicle to protect the bottom from soiling of rain water and mud, and scratches by thrown up pebbles and gravel. In terms of guaranteeing a sufficient rigidity that endures soiling and scratches, such exterior components are made hard using materials such as synthetic resin and synthetic rubber. However, such a hard exterior component produces impact noise (chipping noise) when hit by rain water, mud, grave, and pebbles. Such chipping noise is propagated to the passenger compartment. Thus, such a hard exterior component does not contribute to improvement of quietness in the passenger component, and can be the source of noise in some cases.
To reduce such chipping noise, for example, Japanese Laid-Open Patent Publication No. 2000-264255 discloses a fender liner that is made of a hard fiber plate. The hard fiber plate is formed by bonding fibers with binder, fusion bonding fibers with hot melt resin powder, or heat fusion bonding the mixture of fibers and lower melting point fibers. Japanese Laid-Open Patent Publication No. 2000-264255 discloses that a fender liner made of hard fiber plate is light and has cushioning property, and therefore reduces pitching noise since it softens the impact of collision of dirt, pebbles, and water.
Other than pitching noise, noises that are propagated to the passenger compartment include pattern noise. Pattern noise refers to scratching noise produced by contact between treads (parts that contact the road surface) of tires and the road surface when the vehicle is moving.
To reduce the propagation of noise such as the above described chipping noise and pattern noise to the passenger compartment, for example, Japanese Laid-Open Patent Publication No. 2004-142675, Japanese Laid-Open Patent Publication No. 2004-299626, and Japanese Laid-Open Patent Publication No. 2004-359066 each discloses an exterior component made of sheet material containing nonwoven fabric. Nonwoven fabric is formed by physically intertwining a number of fibers, or tying a number of fibers with binder. An exterior component formed of a sheet material containing such nonwoven fabric has minute spaces (cells) surrounded by intertwined fibers. The cells absorb noises such as pattern noise and chipping noise, thereby reducing the propagation of noises to the passenger compartment. Japanese Laid-Open Patent Publication No. 2004-359066 discloses that a sheet material has a laminated structure of a plurality of stacked layers, and each of the layers has a different function.
In recent years, there is an increasing demand for quietness in vehicle passenger compartments. This trend is applied to all sorts of vehicles. Particularly, the trend is noticeable in hybrid vehicles and fuel cell vehicles, which have been developed in view of minimizing damage to the environment. To meet such needs, latest vehicles tend to have a function to reduce noise produced by power source such as an internal combustion engine and an electric motor, and power transmission system. In addition to reduction of noise produced in such vehicle drive systems, reduction of noise audible in the passenger compartment is an important challenge.
Noises audible in the passenger compartment include road noise in addition to above mentioned chipping noise and pattern noise. Road noise is a muffled noise that is produced when vibration of wheels is transmitted to the vehicle body through suspensions and the vibration of the vehicle body vibrates the air in the passenger compartment. The sources of chipping noise, pattern noise, and road noise cannot be easily removed. Therefore, to reduce audible noise in the passenger compartment, vibration of the vehicle body caused by chipping noise, pattern noise, and road noise needs to be suppressed.
To further reduce noise, the fender liner disclosed in Japanese Laid-Open Patent Publication No. 2000-264255 may be modified to increase the cushioning property, thereby reducing the impact of hitting dirt, pebbles and water (chipping). However, increase in the cushioning property is expected to lower the rigidity. Accordingly, the endurance against is predicted to be lowered. Further, although Japanese Laid-Open Patent Publication No. 2000-264255 discloses reduction of chipping noise, the publication neither disclose nor suggests reduction of scratching noise and muffled noise such as pattern noise or road noise. On the other hand, although Japanese Laid-Open Patent Publication No. 2004-359066 discloses that the sound absorption effect is increased as the number of the cells is increased, a mere increase in the number of cells may reduce the rigidity. Thus, the durability against chipping is predicted to be lowered. Therefore, it is difficult to design an exterior component that satisfies both demands related to the noise reduction capability and the durability against chipping.
In exterior components having nonwoven fabric as disclosed in the above publications, water derived from rain and snow can enter the cells and taken in. An exterior component that has absorbed water increases its weight by the weight of the absorbed water. The increase in the weight can be a cause of deflection and deformation, and reduce the attachment strength of the exterior component with respect to the vehicle body. That is, the rigidity of an exterior component containing nonwoven fabric is sufficient in a normal state, or in a dry state, but insufficient for enduring the increase in weight due to absorbed water. Accordingly, Japanese Laid-Open Patent Publication No. 2004-142675 discloses an exterior component having a water repellent portion so that water does not easily collect on the surface of the exterior component.
However, in the case of an exterior component that contains nonwoven fabric, providing such water repellent portion is not sufficient for completely preventing absorption of water. That is, such a water repellent portion is capable of preventing water that temporarily collects on the surface of the exterior component from being absorbed by the component. However, as for water that is thrown up by a wheel and smashes against the exterior component, and water that stays on the component, the water repellent portion cannot sufficiently suppress such water absorption by the component. To prevent the absorption of water completely, the cells may be blocked. If this is the case, however, sound absorption effect of the cells cannot be obtained. Thus, there is no point in using nonwoven fabric as a material for the exterior component. Therefore, in the case of an exterior component containing nonwoven fabric, it is difficult to eliminate absorption of water and problems caused by such water absorption, while maintaining the sound absorption effect of the cells.


The invention relates to a process for the preparation of aqueous dispersions of latex particles having a heterogeneous morphology by a semicontinuous emulsion polymerization, comprising the emulsion polymerizing of ethylenically unsaturated (co)monomers, accompanied by, the addition of cationic and/or anionic and/or nonionic emulsifiers and/or protective colloids as stabilizers, which are directly used as such or synthesized in situ, the semicontinuous emulsion polymerization being performed in the presence of the stabilizer or stabilizers with a monomer mixture, which a) contains at least one nonionic, ethylenically unsaturated monomer with a glass transition temperature Tg above about 30xc2x0 C. in a quantity of about 10 to 70 wt. %, based on the total weight of ethylenically unsaturated (co)monomers and b) at least one hydrophilic, ethylenically unsaturated monomer in a quantity of about 5 to 30 wt. %, based on the total weight of ethylenically unsaturated (co)monomers.

The invention relates to a process for the preparation of aqueous dispersions of latex particles having a heterogeneous morphology. The invention also relates to the latex particles preparable with the process, the aqueous dispersions and redispersible powders, as well as the use thereof.
Emulsion polymerization is a known procedure for the production of latex polymers having a clearly defined structure. In this connection particular interest is placed on a process leading to the production of so-called heterogeneous latex morphologies. As a result of their molecular structure, such latex particles provide special characteristics and a wide range of uses. In this heterogeneous structure of the latex particles, a distinction is made between a relatively hydrophobic and a relatively hydrophilic area. For thermodynamic equilibrium reasons, under normal conditions there is a hydrophilic shell (outer phase) and a hydrophobic core (inner phase), because these can be more easily produced in general by emulsion polymerization. However, it is much more difficult to produce systems with a so-called inverse core-shell structure, in which the core is hydrophilic and the shell hydrophobic. Increasing importance is being attached thereto as a result of the possible encapsulation of functionalized, hydrophilic polymers.
Such a structure of polymer particles with inverse core-shell structure and their production by emulsion polymerization are described by EP 426 391 A2. According to the process described therein 2 to 60 parts by weight in the form of the core polymer (A) are produced by the emulsion polymerization of 10 to 80 parts by weight of an acrylate ester with an alkyl group with 1 to 3 carbon atoms having 90 to 20 parts by weight of a further monomer. The shell polymer (B) is subsequently produced, e.g. by emulsion polymerization from 98 to 40 parts by weight of at least one vinyl monomer, after which the core polymer is hydrolyzed in alkaline manner. Preferably the shell polymer has a glass transition temperature of at least 50xc2x0 C. Mention is also made of surfactants, which can optionally be used in a quantity of 0.1 to 10 wt. %. The particles are used as a pigment or filler in paints and paper coatings. An inadequate storage stability is a disadvantage of the dispersions described. In addition, the dispersed core-shell particles do not have a satisfactory resistance to water, so that after a certain time it is no longer possible to use them. The particle sizes which can be produced with the process of EP 426 391 A1 are also very ununiform and spread over a wide range, so that the uniform particle sizes necessary in certain applications are not available.
An encapsulation of hydrophilic polymers and the production thereof are also described in EP 696 602 A1. In the latter, the hydrophilic core is formed from 5 to 100 wt. % hydrophilic monomer and 0 to 95 wt. % nonionic monomer and the hydrophobic shell of 90 to 99.99 wt. % nonionic monomer and 0.1 to 10 wt. % acid-functionalized monomer. The acid-functionalized monomer is a carboxylic acid monomer, preference being given to (meth)acrylic acid. It is also possible to use non-polymerizable carboxylic acids, such as C6-C12 aliphatic or aromatic monocarboxylic or dicarboxylic acids. Styrene is mentioned as the preferred nonionic monomer for the shell. The particle size is preferably between 50 and 2000 nm. Additionally the core can contain less than 20, preferably 0.1 to 3 wt. % of multiply unsaturated monomers or 0.1 to 60 wt. % butadiene.
In the preparation process of EP 696 602 A1, the time sequence during the addition of the acid monomer in preparing the shell is of vital importance. If the core particle size is below 130 nm, the acid monomer must be added during the first 50% of the addition of the total shell monomer, preferably during the first 25% and in particularly preferred manner during the first 10%. If the core particle size exceeds 130 nm, the acid monomer must be added during the 100% addition of the total, added shell monomer, preferably during the first 50%, in particularly preferred manner during the first 25% and more especially during the first 10%. The core polymer can also be prepared by means of a seed, the average particle size being about 30 to 200 nm. Optionally both anionic and nonionic emulsifiers can be used, it being possible to use 0 to 0.75 wt. % emulsifier, based on the total core polymer, for the preparation of the core. It is unnecessary to add additional emulsifier during the preparation of the shell, but mention is made of tile addition of 0.05 to 2 wt. %, based on the total shell polymer weight. By adding bases the acid functions of the core can be neutralized and then the core swells, the polymers diffuse out of the core and particles with voids are formed. The latex particles prepared with the voids produced are more particularly used in aqueous coating compositions, such as water-based paints and paper coatings and give the latter brightness and body. A disadvantage of this process is the timing which must be carefully respected during the addition of the acid polymer for polymerizing the shell polymer, as well as the dependence of the alternative procedure on the core polymer particle size. The polymerization process is also very complex and technically complicated as a result of the described alternatives. The emulsifiers are only optionally used, mention only being made of anionic and nonionic emulsifiers.
The problem of the invention is to so further develop the aqueous dispersions or latex particles prepared according to the aforementioned processes, that whilst maintaining advantageous characteristics or in individual cases providing improved characteristics, the process control and the selection of the starting materials can be made more flexible, whilst simultaneously providing a simplified production procedure. In addition, the preparable latex particles, both in dispersed form and in powder form, must have a good storage stability and water resistance. In addition, these dispersions or the dispersed latex particles must be improved in such a way that during their final applications, such as e.g. in plastics-containing, cement-bound systems, as a result of desirable consecutive reactions, they lead to advantageous use products with improved processability and characteristics.
According to the invention, the above problem is solved by a process for the preparation of aqueous dispersions of latex particles having a heterogeneous morphology by a semicontinuous emulsion polymerization, comprising the emulsion polymerizing of ethylenically unsaturated (co)monomers, accompanied by the addition of cationic and/or anionic and/or nonionic emulsifiers and/or protective colloids as stabilizers, which are directly used as such or synthesized in situ, the semicontinuous emulsion polymerization being performed in the presence of the stabilizer or stabilizers with a monomer mixture, which
a) contains at least one nonionic, ethylenically unsaturated monomer with a glass transition temperature Tg above about 30xc2x0 C. in a quantity of about 10 to 70 wt. %, based on the total weight of ethylenically unsaturated (co)monomers and
b) at least one hydrophilic, ethylenically unsaturated monomer in a quantity of about 5 to 30 wt. %, based on the total weight of ethylenically unsaturated (co)monomers.

PROCESS FOR THE PREPARATION OF AQUEOUS DISPERSIONS OF LATEX PARTICLES HAVING A HETEROGENEOUS MORPHOLOGY, THE LATEX PARTICLES OBTAINABLE WITH THE PROCESS, THE DISPERSIONS AND REDISPERSIBLE POWDERS, AS WELL AS THE USE THEREOF

National Starch and Chemical Investment Holding Corporation


This invention relates to an improvement to a process for synthesizing cellulose aminomethanate which comprises slurrying cellulose in an aqueous caustic solution, in the presence of urea; steeping the slurried mixture for a time sufficient to permit swelling of the cellulose for uniform distribution of the urea; concentrating the steeped mixture and treating an extraction of the concentrate with an ion-exchanger. When cellulose aminomethanate is manufactured from product prepared in accord with this process, it has a uniform distribution of substituent throughout the cellulose at the molecular level and comprises a suitable product for manufacturing sausage casing.

(a) Field of the Invention
This invention relates to a process for synthesizing cellulose aminomethanate which has utility in the manufacture of sausage casing and other cellulose products.
(b) History of the Prior Art
Cellulose xanthate, dissolved as viscose, has been utilized for many years in the manufacture of regenerated cellulose film which has particular utility as sausage casings. With the increase in environmental awareness, concerns have been raised to the environmental management of flammable and toxic reactants and by-products of the viscose manufacturing process. The rapidly escalating cost of by-product management, coupled with the intrinsic costs of additives, which are necessary when utilizing viscose for regenerated cellulose sausage casings, has forced the sausage casing industry to search for viable alternatives to current viscose manufacturing processes.
One alternative, which has more recently been the focus of research for possible replacement of the viscose process in the sausage casing industry is the use of ammonia derivatives, such as urea, reacted with cellulose to form a soluble cellulose derivative. The use of such materials is preferable as byproducts are easily managed and do not appear to represent significant environmental impact. U.S. Pat. Nos. 1,771,461; 2,134,825; and 2,129,708 comprise some of the early work in that technology demonstrating that film products are obtainable that have utility. Though the final products formed showed potential for use as a film, it wasn't until U.S. Pat. No. 4,789,006 that a product was produced having a combination of properties commercially acceptable for use as sausage casings.
Various different terminology has been used to describe the products of cellulose and urea, such as cellulose aminoformates, cellulose carbamates, cellulose aminomethanoates and cellulose aminomethanates as adopted in U.S. Pat. No. 4,789,006. To deter further confusion, the products formed with cellulose and urea as presented in the above patents and hereinafter will be referred to as cellulose aminomethanates.
Even though a cellulose aminomethanate product can now be made which is suitable for use as a sausage casing, problems still exist in the manufacturing process occasioned by the difficulty of removing prior art carriers, such as sodium hydroxide, used to obtain uniform distribution of the urea through the cellulose structure prior to the formation of the cellulose aminomethanate. This need for uniform distribution of the urea is disclosed in U.S. Pat. No. 4,404,369 and achieved by using liquid ammonia which can be subsequently removed by volatilization. However, liquid ammonia is highly volatile, toxic, pungent, forms explosive mixtures with air and requires excessive refrigeration and special equipment for safe handling and recovery.
In a later process, disclosed in European Patent Application No. 85890246.3 (1985), uniform distribution was achieved by using high concentrations of sodium hydroxide which was then washed out with neutral aqueous urea. Such process, however, requires the handling of large volumes of liquid and creates associated recovery problems.
It is an object of this invention to improve the distribution of urea throughout the cellulose structure prior to the formation of cellulose aminomethanate.
It is another object of this invention to provide an improved cellulose aminomethanate material having uniform distribution of aminomethanate substituent.
It is a further object of this invention to provide a convenient means for processing cellulose which has been steeped in sodium hydroxide.
It is a still further object to provide a means to reduce and/or eliminate the growth in volume of extracting liquids for successive batches of urea-alkali steeped pulps.
It is still another object to provide a means to allow recycle of alkali and urea used for steeping.

Cellulose aminomethanate by ion-exchange extraction


An organic light-emitting display device and a method of manufacturing the organic light-emitting display device are disclosed. The organic light-emitting display device includes a bottom capacitor electrode that is formed over the same plane as an active layer of a thin film transistor and includes a semiconductor doped with ion impurities, a pixel electrode, and a top capacitor electrode formed over the same plane as a gate electrode, wherein a contact hole entirely exposing the pixel electrode and the top capacitor electrode is formed.

1. Field
The present invention relates to organic light-emitting display devices and methods of manufacturing the same.
2. Description of the Related Technology
Organic light-emitting display devices are typically lightweight and thin, and have wide viewing angles, short response times, and reduced power consumption, and thus are of great interest as next-generation display devices.

Organic light-emitting display device and manufacturing method of the same


One method occurs at a test controller of a network test system implemented using at least one processor. The method includes receiving test configuration information for configuring a testing scenario comprising an emulated data center environment implemented using multiple network emulation platforms that are interconnected, wherein the test configuration information includes switching fabric topology information for defining the emulated data center environment; configuring, using the test configuration information, the emulated data center environment including sending a set of configuration instructions to each of the network emulation platforms, wherein each set of configuration instructions include resource allocation instructions for allocating ASIC switch resources of a respective network emulation platform to one or more emulated switches; and configuring, using the test configuration information, a test session for testing a system under test (SUT) using the emulated data center environment and a network visibility infrastructure.

Data center environments typically provide high reliability and security and typically include networked resources (e.g., virtual or physical servers connected via network switches) sharable by multiple clients of the data center operator. Large data centers are industrial scale operations using as much electricity as a small town. Various data centers may utilize virtualization. For example, a data center may implement multiple virtual machines (VMs) that communicate via a virtual switch (vSwitch), e.g., virtual servers, using a physical central processing unit (CPU)-based server or node in the data center. In this example, each VM may execute an operating system and other software, where each VM may appear as a physical server to end users.
It will be appreciated that an emulated switch of the type described in this disclosure is distinctly different from the entity referred to commonly in the industry as a virtual switch. More particularly, a virtual switch is a software application that runs on top of a CPU, which allows communication between virtual machines, where the virtual machines are administered by a virtual machine hypervisor. A vSwitch does not subdivide and allocate resources of an underlying physical switch ASIC chip into multiple emulated switches, but instead creates a software representation of a completely virtual switch (i.e., there is no mapping to underlying physical switch ASIC hardware).
When testing data center equipment, it is important to make sure that testing mimics real world scenarios and conditions. For example, when testing a data center server or related applications, it may be necessary to mimic or emulate resources in the data center.
Accordingly, a need exists for methods, systems, and computer readable media for network testing using an emulated data center environment.

Methods, systems, and computer readable media for network testing using an emulated data center environment


A memory system includes a sense amplifier for detecting content of data memory cells by comparison with a voltage stored in a reference cell. The sense amplifier may comprise a comparator, first and second load circuits, and a low impedance circuit. A first input of the comparator is coupled to the low impedance circuit and a reference voltage node. A second input of the comparator is coupled to a data voltage node. The first load circuit loads a reference cell coupled to the reference voltage node. The second load circuit loads a data cell coupled to the data voltage node.

The present invention relates to a sense amplifier, and more particularly to a sense amplifier for a multilevel cell memory.
Memory systems include sense amplifiers for detecting content stored in memory cells. In digital multilevel memories, reference cells store reference values for comparison with detected content in memory cells. The speed of and the loading on the sense amplifier impacts its performance.

Sense amplifier for low voltage high speed sensing


An electronic component includes a substrate, a capacitor, and a wiring. The capacitor has a multilayer structure including a first electrode film provided on the substrate, a second electrode film of 2 to 4 μm in thickness disposed to face the first electrode film, and a dielectric film interposed between the first and the second electrode film. The wiring includes a joint portion connected to the second electrode film, on the opposite side of the dielectric film.

1. Field of the Invention:
The present invention relates to an electronic component that includes a capacitor provided on a substrate, for example formed by semiconductor processing technology.
2. Description of the Related Art:
In a radio frequency (RF) system such as a mobile phone or a wireless LAN, signals are subjected to phase-matching for satisfactory transmission among functional devices constituting the system. Accordingly, the input/output (I/O) terminal of each device is provided with a passive element that includes a passive component such as an inductor or a capacitor, and that acts as a phase shifter for controlling the phase of the signals.
In the RF system, a SAW filter is employed for use as a narrow-band frequency filter. The SAW filter, which includes a piezoelectric element, produces a difference in potential between piezoelectric element electrodes because of a piezoelectric effect, when a physical impact or a thermal effect is applied to the SAW filter or the piezoelectric element thereof during the manufacturing process of the apparatus in which the SAW filter is incorporated. In this case, a predetermined voltage is applied to an electronic component electrically connected to the SAW filter. The capacitor included in the passive element (phase shifter) is usually electrically connected to the SAW filter, and hence the capacitor has to have a high withstanding voltage (e.g. 150 V or higher), to prevent a dielectric breakdown between the capacitor electrodes, which may occur upon application of a voltage accidentally generated by the SAW filter or the piezoelectric element thereof.
There has been a constant demand for reduction in dimensions of various parts composing RF systems, driven by the increase in number of parts for achieving a higher performance. For making the system smaller in dimensions, an integrated passive device (hereinafter, IPD) manufactured based on a semiconductor processing technology, which includes a plurality of predetermined passive components such as an inductor, a capacitor, a resistor and a filter densely integrated therein, may be employed the passive element (phase shifter). When employing the IPD, the capacitor included therein still has to have a high withstanding voltage, for preventing a dielectric breakdown between the capacitor electrodes, as stated above. Techniques related to the IPD are found, for example, in JP-A-H04-61264 and JP-A-2002-33239.
FIG. 9 is a schematic cross-sectional view showing a part of a conventional IPD 90. The IPD 90 includes a substrate 91, a plurality of passive components each including a capacitor 92, integrated on the substrate 91, an wiring 93 and a protecting film 94. The capacitor 92 has a multilayer structure including an electrode film 92a (lower electrode film), an electrode film 92b (upper electrode film), and a dielectric film 92c. The wiring 93 includes a joint portion 93a connected to the electrode film 92b.
The electrode film 92b has a thickness of approximately 1 μm. For forming the electrode film 92b, a conductor film, which is to subsequently serve as the electrode film 92b, is formed on the substrate 91 to cover the electrode film 92a and the dielectric film 92c already formed on the substrate 91. A resist film given a pattern corresponding to the electrode film 92b is then provided on the conductor film, and an ion milling process is performed utilizing the resist film as the mask, thus to shape the conductor film according to the pattern. When performing such subtractive process to form the electrode film 92b, the thinner the conductor film, or the electrode film 92b is, the more accurately the electrode film 92b can be formed in pattern (hence in area). The precision in area of the electrode film 92b affects the precision in static capacitance of the capacitor 92, which is why the electrode film 92b is formed in a thickness of approximately 1 μm in the conventional IPD 90, for achieving high precision in static capacitance.
In contrast, the wiring 93 (including the joint portion 93a) is formed in a relatively greater thickness. Making the wiring 93 thicker can reduce a resistance thereof, and the reduction in resistance is preferable from the viewpoint of reducing a signal loss through the IPD 90. Accordingly, the wiring 93 is formed in a thickness of approximately 10 μm for example.
The capacitor 92 of the conventional IPD 90, however, often has a withstanding voltage below a practically acceptable level, which has to be addressed. For improving the withstanding voltage of the capacitor 92, it could be an option to form the dielectric film 92c in a greater thickness. Increasing the thickness of the dielectric film 92c, however, requires increasing the area of the electrode film 92b, because otherwise the static capacitance of the capacitor 92 cannot be maintained. Therefore, it is not preferable to increase the thickness of the dielectric film 92c, from the viewpoint of suppressing an increase in dimensions of the capacitor 92, hence the IPD 90.


A method to enable a participant within a plurality of participants in an online group conversation to add at least one additional participant as an observer to the online group conversation is provided. The method may include receiving a request to add the observer to the online group conversation. The method may include adding the observer to the online group conversation. The method may also include detecting a message being sent from the added observer. The method may include redirecting the detected message to the enabled participant. The method may also include displaying the redirected message in a user interface (UI) to the enabled participant. The method may further include detecting a modification or a deletion of the displayed redirected message by the enabled participant. The method may include sending the message to the plurality of participants, whereby the sent message is in an original format or a modified format.

The present invention relates generally to the field of computers, and more particularly to online group conversations.
An online group conversation may be based on emails or instant messaging systems, such as Sametime® (Sametime® and all Sametime®—based trademarks and logos are trademarks or registered trademarks of IBM Corporation and/or its affiliates), Skype® (Skype® and all Skype®-based trademarks and logos are trademarks or registered trademarks of Skype Technologies S.A. and/or its affiliates), WeChat® (Wechat® and all Wechat®—based trademarks and logos are trademarks or registered trademarks of Tencent Holdings Limited and/or its affiliates). In many cases a participant in the online conversation may want to include one or more people to observe the discussion in the conversation in real time, however the participant may not want to explicitly add these observers as active participants in the conversation. In such cases, the participant may want to let the observers know what is going on in the discussion, but does not want to expose the identities of the observers, does not want the observers to participate in the conversation directly, or simply does not want other participants in the conversation to know these observers are watching over the discussion.

Allow hidden and silent observers in a group conversation

International Business Machines Corporation


The present invention relates to a server-processor hybrid system that comprises (among other things) a set (one or more) of front-end servers (e.g., mainframes) and a set of back-end application optimized processors. Moreover, implementations of the invention provide a server and processor hybrid system and method for distributing and managing the execution of applications at a fine-grained level via an I/O-connected hybrid system. This method allows one system to be used to manage and control the system functions, and one or more other systems to co-processor.

Web 1.0 is historically referred to as the World Wide Web, which was originally about connecting computers and making technology more efficient for computers. Web 2.0/3.0 is considered to encompass the communities and social networks that build contextual relationships and facilitate knowledge sharing and virtual web servicing. Traditional web service can be thought of as a very thin client. That is, a browser displays images relayed by a server, and every significant user action is communicated to the front-end server for processing. Web 2.0 is a social interaction that is consisted of the software layer on the client, so the user gets quick system response. The back-end storage and retrieval of data is conducted asynchronously in the background, so the user doesn't have to wait for the network. Web 3.0 is geared towards the 3 dimensional vision such as in virtual universes. This could open up new ways to connect and collaborate using 3D shared. Along these lines, web 3.0 describes the evolution of Web usage and interaction along several separate paths. These include transforming the Web into a database, a move towards making content accessible by multiple non-browser applications.
Unfortunately, the traditional server cannot efficiently handle the characteristics of Web 3.0. No existing approach addresses this issue. In view of the foregoing, there exists a need for an approach that solves this deficiency.

Server-processor hybrid system for processing data


A bicyclo[2.2.1]heptane derivative represented by following general formula (1):

High viscosity hydrocarbon base materials are used for tackfiers for adhesives and process oils for rubber and resins. As the high viscosity hydrocarbon base material, polybutene, ethylene-propylene oligomers and poly-α-olefins have heretofore been used. However, the above base materials have a drawback in that materials which can be used in combination are restricted due to poor compatibility with various organic substances.
When workability in mixing is considered, it is preferable that viscosity is small during mixing so that the mixing is facilitated. Therefore, it is preferable that the base material has a viscosity-temperature characteristic such that viscosity is low at high temperatures (during the mixing) and high at temperatures around the room temperature (during the use). In other words, a small viscosity index is preferable. The conventional base materials described above have a drawback in that the viscosity index is 100 or greater and the change in viscosity with temperature is small.
The present invention has been made to overcome the above drawbacks and has an object of providing a compound exhibiting excellent compatibility with various organic substances and has a small viscosity index.

Abstract: wherein R1 and R2 each represent hydrogen atom or methyl group, and R3 represents methyl group or ethyl group. The derivative is suitable as a high viscosity hydrocarbon base material used for tackfiers for adhesives and process oils for rubber and resins.


A navigation update system includes a key of a vehicle. The key includes a memory storage device storing data for a navigation device of the vehicle. The data includes instructions for execution by the navigation device and/or map data for use by the navigation device to provide navigation services to a user of the vehicle.

1. Priority Claim
This application claims priority under 35 U.S.C. §119 to the European patent application number 09010527.1, filed Aug. 15, 2009, entitled "Key of a Vehicle and a Navigation Device."
2. Technical Field
The invention is directed to a navigation update system that may include a key of a vehicle and a navigation device for providing a navigation service.
3. Related Art
In order to select a route for a vehicle to guide it to a desired destination, vehicles quite often are equipped with navigation devices. Such a navigation device comprises software, and has access to map data. The software enables the navigation device to evaluate the map data to find an appropriate route from a starting point to the destination. However, the availability of roads may change with time. For example, new roads may be put into operation, existing roads may be closed for vehicles, or may be changed to one-way roads. Hence, to permit proper operation of a navigation device, up-to-date map data may be provided to the navigation device from time to time. Processing of amended map data may also require updates, from time to time, of the software instructions executed by the navigation device.
New map data and/or new software instructions may be provided to the user on computer-readable media; often, CD-ROMs are used for this purpose. Then, it is left to the user to insert the computer-readable media into the navigation device and start updating it by transferring the new map data and/or new software instructions to the navigation device. However, the user has to handle the CD very carefully to protect it from dirt and scratches which would render it useless. Moreover, the user has to refer to the instruction manual of the navigation system to learn how to operate the navigation device such that an update of data or software instructions can be performed. This makes updating the navigation system an awkward task for the user.
In view of this, there is a need for a system providing an easier way for the user to update data and/or software instructions of a navigation system in a vehicle.


The present invention relates to a thermally enhanced interconnect substrate and a method of making the same. In accordance with one preferred embodiment, the method includes: forming a stopper on a metal layer of a laminate substrate; removing a selected portion of the metal layer to form a paddle layer; mounting a semiconductor device on the paddle layer using the stopper as a placement guide for the semiconductor device; attaching a stiffener to the laminate substrate; forming first and second build-up circuitries that cover the semiconductor device, the paddle layer and the stiffener at both sides; and providing a plated through-hole that provides an electrical connection between the first and second build-up circuitries. Accordingly, the paddle layer can provide excellent heat spreading, and the stopper can accurately confine the placement location of the semiconductor device and avoid the electrical connection failure between the semiconductor device and the build-up circuitry.

1. Field of the Invention
The present invention relates to a thermally enhanced interconnect substrate for a semiconductor assembly and a method of making the same, and more particularly to a thermally enhanced interconnect substrate with embedded semiconductor device and built-in stopper and a method of making the same.
2. Description of Related Art
As market trend demands for thinner, smarter and cheaper portable electronics, semiconductor devices for use in these equipments are required to further shrink their size and improve electrical performances at lower cost. Among all the efforts, embedding or built-in semiconductor chip in printed wiring board to form a module assembly is considered the most effective approach since it can drastically reduce the overall weight, thickness and improve electrical performance through a shorten interconnect distance.
However, the attempt of embedding chip in a wiring board can encounter many problems. For example, the chip to be embedded is known to vertically and laterally shift during die attach and encapsulation/lamination processes due to thermal characteristics of plastic materials. The CTE mismatch between metal, dielectric and silicon at various stages of thermal treatment can result in misalignment of the build-up interconnect structure to be deposited thereon. U.S. Pat. No. 7,935,893 to Tanaka et. al., U.S. Pat. No. 7,944,039 to Aral and U.S. Pat. No. 7,405,103 to Chang disclose various alignment methods to address manufacturing yield concern. None of these approaches offers a proper solution or effective method for controlling die movement because the underneath adhesive will reflow during curing and therefore dislocates the attached die from the pre-determined location even a highly precise alignment mark and equipment are applied. U.S. Patent Application 2010/0184256 to Chino discloses a resin sealing method to fix the semiconductor device adhered to the adhesive layer formed on the support body. This approach may be effective in controlling die from further movement during sealing process, it does not provide any control or adjustment for die attach process and the mis-registration is unavoidable due to die attach adhesive reflows.

Thermally enhanced interconnect substrate with embedded semiconductor device and built-in stopper and method of making the same


This storage controller providing a volume for storing data transmitted from a host system includes a management unit for managing the data written in the volume with a first block area, or a second block area in the first block area which is smaller than the first block area; a snapshot acquisition unit for acquiring a snapshot of the volume at a prescribed timing; and a transfer unit for transferring the data of the volume acquired with the snapshot of the snapshot acquisition unit to an external device with the first block area or the second block area.

The present invention relates to a storage controller and its data management method, and, for instance, can be suitably applied to a storage system that replicates a volume of a storage controller storing data transmitted from a host system in another storage controller.
Conventionally, known is technology for managing the backup of a volume of a storage controller (hereinafter referred to as a "primary storage controller") storing data transmitted from a host system operated in a certain site for disaster recovery of the storage system in a volume of a storage controller (hereinafter referred to as a "secondary storage controller") established at a remote site (this technology is hereinafter referred to as "remote copying"), and various other related technologies have been proposed.
For example, in Japanese Patent Laid-Open Publication No. H11 (1999)-259348, the primary storage controller has at least one volume and transmits a request for acquiring at least a part of the snapshot of such volume to a secondary storage controller, and the secondary storage controller replies to the request for acquiring the snapshot and has a volume which is a replicated copy of the volume of the primary storage controller, and the volume of the primary storage controller is replicated in the volume of the secondary storage controller by acquiring the snapshot of the corresponding portion.
Further, for instance, in Japanese Patent Laid-Open Publication No. 2005-267569, the storage controller controls the reading and writing of data from and in a first volume, controls the data newly stored in the volume to be written in a second volume as differential data per generation, and manages differential data by providing, in an area of a memory, a snapshot management table managing the relationship of differential data per generation stored in the second volume. And, the storage controller generates a virtual volume of a specific generation with the snapshot management table, and thereby performs remote copying with this virtual volume.
Moreover, for example, in Japanese Patent Laid-Open Publication No. 2005-275494, the secondary storage controller receives difference-related information from the primary storage controller, generates generation management information based on the received difference-related information, and restores the stored contents of the designated generation based on the generated generation management information and the volume of the secondary storage controller.

Storage controller and data management method


An implantable universal pacing and defibrillating system provides efficacious sensing, pacing, and cardioversion/defibrillation in all four chambers of the heart. The system includes three leads with one lead being configured for implant in the coronary sinus for sensing, pacing, and defibrillating in both the left atrium and left ventricle. The leads also provide a plurality of different electrode configurations for both ventricular and atrial defibrillation. Sequential primary and secondary defibrillation shocks may be employed to advantage for depolarizing essentially all of the ventricular or atrial myocardium.

The present invention generally relates to a method of defibrillating a heart with an implantable cardiac stimulation system. The present invention more particularly relates to such a method wherein a defibrillating stimulation pulse is applied simultaneously across a plurality of different chambers of the heart.
Implantable cardiac stimulation devices are well known in the art. Such devices may include, for example, implantable cardiac pacemakers and defibrillators. The devices are generally implanted in a pectoral region of the chest beneath the skin of a patient within what is known as a subcutaneous pocket. The implantable devices generally function in association with one or more electrode carrying leads which are implanted within the heart. The electrodes are usually positioned within the right side of the heart, either within the right ventricle or right atrium, or both, for making electrical contact with their respective heart chamber. Conductors within the leads couple the electrodes to the device to enable the device to sense cardiac electrical activity and deliver the desired therapy.
Traditionally, therapy delivery had been limited to the venous, or right side of the heart. The reason for this is that implanted electrodes can cause blood clot formation in some patients. If a blood clot were released arterially from the heart left side, as for example the left ventricle, it could pass directly to the brain potentially resulting in a paralyzing or fatal stroke. However, a blood clot released from the right heart, as from the right ventricle, would pass into the lungs where the filtering action of the lungs would prevent a fatal or debilitating embolism in the brain.
Recently, new lead structures and methods have been proposed and even practiced for delivering cardiac rhythm management therapy to the left heart. These lead structures and methods avoid direct electrode placement within the left atrium and left ventricle of the heart by lead implantation within the coronary sinus region of the heart. As used herein, the phrase xe2x80x9ccoronary sinus regionxe2x80x9d refers to the venous vasculature of the left ventricle, including any portions of the coronary sinus, great cardiac vein, left marginal vein, left posterior ventricular vein, middle cardiac vein, and/or small cardiac vein or any other cardiac vein accessible by the coronary sinus.
It has been demonstrated that electrodes placed in the coronary sinus region of the heart may be used for left atrial pacing, left ventricular pacing, or cardioversion and defibrillation. These advancements enable implantable cardiac stimulation devices to address the needs of a patient population with left ventricular dysfunction and/or congestive heart failure which would benefit from left heart side pacing, either alone or in conjunction with right heart side pacing (bi-chamber pacing), and/or defibrillation.
Cardiac leads intended for use in the left heart via the coronary sinus region are difficult to position due to the tortuous venous routes of the human anatomy. Moreover, to provide both pacing and defibrillation of both the left atrium and the left ventricle from the coronary sinus region with multiple leads employing the appropriate types of electrodes is extremely difficult given the space constrains to accommodate multiple leads in the coronary sinus region. Hence, such implants are too cumbersome, difficult, and time consuming to perform and would likely result in compromised performance or system malfunction.
Universal pacing and defibrillation systems, capable of pacing and defibrillating all four heart chambers of the heart would require numerous pacing and defibrillation electrodes to be employed within the heart and its coronary venous system. To implement such a universal pacing and defibrillation system utilizing current state of the art lead configuration approaches, an inordinate number of leads would be required. This would result in lengthy implant procedures and possibly more leads than the human anatomy is able to accommodate. An inordinate number of leads may also make it difficult to accurately locate each electrode at a most efficacious position within the heart.
Efforts to minimize the number of required leads could also be fraught with potential obstacles. Such an effort would most likely include loading a lead up with too many electrodes. While this would reduce the number of required leads, such a lead would be difficult to implant. More importantly, owing to the differences in physiology from one patient to another, such a lead would most likely not xe2x80x9cfitxe2x80x9d a large number of patients in terms of resulting efficacious electrode positioning.
Efforts to achieve a universal pacing and defibrillation system, if successful, could provide significant improved therapies. Coordinated right heart and left heart pacing therapies would be made possible. Further, improved defibrillation therapies would also be made possible. Such therapies could include improved defibrillation energy distribution within the heart and/or new and improved sequential defibrillation pulse techniques.
The present invention provides a method of providing defibrillation stimulation to a heart with an implantable cardiac stimulation system wherein the stimulation pulse is applied with electrode configurations to deliver the stimulation pulse simultaneously across a plurality of chambers of the heart.
In accordance with one aspect of the invention, the stimulation pulse is applied with a first electrode configuration between a first chamber of the heart and third and fourth chambers of the heart and simultaneously applied with a second electrode configuration between a second chamber of the heart and the third and fourth chambers of the heart, one of the chambers of the heart being the left ventricle. In accordance with this aspect of the present invention, the first chamber may be the right atrium, the second chamber may be the right ventricle, the third chamber may be the left atrium and the fourth chamber may be the left ventricle. Alternatively, the first chamber may be the right atrium, the second chamber may be the left atrium, the third chamber may be the right ventricle, and the fourth chamber may be the left ventricle.
In accordance with a further aspect of the present invention, the conductive case of the implantable device may be used as an electrode. For example, the stimulation pulse may be applied with a third electrode configuration between the case and either the first and second chambers or the third and fourth electrodes.
In accordance with another aspect of the present invention, the stimulation pulse may be applied between the left ventricle of the heart and the case while simultaneously applying the stimulation pulse between a further chamber other than the left ventricle and the case. The further chamber may be the right ventricle.
In accordance with further aspects of the present invention, a defibrillation electrode is placed in electrical contact with each of the four chambers of the heart, a first common connection is formed with a first plurality of the electrodes, a second common connection is formed with a second plurality of the electrodes, and the stimulation pulse is delivered between the first and second connections. The electrodes for the left atrium and left ventricle may be electrically contacted with the left atrium and left ventricle by placing the electrodes within the coronary sinus region of the heart adjacent those chambers.

Method of defibrillating a heart with electrode configurations including a left ventricular defibrillation electrode