Disclosed is a ball grid array package with stacked center pad chips, which realizes a BGA package with stacked chips using center pad type semiconductor chips, and a method for manufacturing the same. The semiconductor chips are glued on each of upper and lower circuit boards, which have active surfaces facing each other; the chip pads are connected to each of the upper and lower circuit boards with gold wires; the upper and lower circuit boards are joined together with bumps interposed between them for electrical connection; the upper circuit board is included in a package mold; and the opposite ends of the lower circuit board are exposed to the lower portion of the package mold. The lower circuit board can be made of flexible insulation film. The exposed opposite ends of the lower circuit board can have solder balls formed thereon. Also, the opposite ends of the lower circuit board may be joined to a printed circuit board. Solder balls may be formed on the lower surface of the printed circuit board. The upper circuit board may be composed of a lead frame. The package according to the present invention is a stacked package capable of increasing memory capacity of a single package by at least 200% and combining both advantages of FBGA packages and of center pad type semiconductor chips.

1. Field of the Invention
The present invention relates to a semiconductor package, and more particularly to a ball grid array package with stacked center pad chips, which realizes a stacked package of a Fine Ball Grid Array (FBGA) type by stacking more than one center pad type semiconductor chips, and a method for manufacturing the same.
2. Description of the Prior Art
In the semiconductor industry, packaging technology for IC chips is continuously progressing in order to meet the desire for compactness and improved mounting reliability. Furthermore, as the performance of electronic devices is getting better, efforts have been made to mount a larger number of semiconductor packages on a substrate having a limited size. As a result of such efforts, there has been proposed a so-called "stacked package".
The stacked package was devised in order to increase memory capacity by stacking memory chips of a same size and function or to maximize the performance and efficiency of products by assembling various kinds of semiconductor chips with different size and function. There are many types of stacked packages according to the corresponding end-use products, makers, etc. One example of stacked packages according to the prior art is illustrated in FIG. 1.
The stacked package shown in FIG. 1 belongs to a package-stacking type. In other words, the stacked package is constructed by stacking individual packages 11, 12 and classified as a Thin Small Outline Package (TSOP) type. Each of the individual packages 11, 12 in FIG. 1 comprises a semiconductor chip 13 therein and uses a Lead-on-Chip (LOC) lead frame. The lead frame has an internal lead 14 glued on the upper surface of the semiconductor chip 13 by an adhesive tape 15 and connected therewith electrically by a gold wire 16. The stacked packages 11, 12 are connected together electrically by a separate connecting lead 17. The connecting lead 17 is joined to each outer lead 18 of the respective lead frames and acts as an outer connection terminal of the stacked package 10.
However, because of their large mounting area and considerable height, stacked packages 10, as mentioned above, are hardly applicable to such systems as information communication devices, which require compactness and thinness. They are not suitable for high-speed devices either, since they use lead frames 14, 17, 18. Moreover, as the path between a mounting point and the semiconductor chip 14 of the upper package 12 is longer than the path between the mounting point and the semiconductor chip 13 of the lower package 11, there exists a difference in electrical characteristics.
Accordingly, a Ball Grid Array (BGA) package using solder balls as outer connection terminals has been proposed, for the purpose of improving electrical characteristics by minimizing both the surface mounting area of a semiconductor package and the electrical connection length thereof. Referring to FIG. 2, there is illustrated a so-called "BGA package with stacked chips", which has been basically configured as a BGA package and has semiconductor chips stacked therein.
As shown in FIG. 2, individual semiconductor chips 23, 24 are stacked within the package mold 27 of the BGA package with stacked chips 20. Instead of lead frames, a printed circuit board (PCB) 21 and solder balls 28 are used in the package 20. The lower semiconductor chip 23 is glued on the PCB 21 having wirings 22 attached thereon with adhesives 25, and then the upper semiconductor chip 24 is glued on the lower semiconductor chip 23. Each of the semiconductor chips 23, 24 is connected electrically with the wirings 22 of the PCB 21 by means of gold wires 26. The PCB 21 is provided with solder balls 28 on its lower surface for electrical connection with the wirings 22. The solder balls 28 act as outer connection terminals for the package 20.
However, the BGA packages with stacked chips, as explained above, can use nothing but semiconductor chips of a so-called "side pad type". On the active surfaces of semiconductor chips such as DRAM chips, a number of chip pads 23a, 24a are formed for performing input/output with external elements. If the chip pads 23a, 24a are formed on the edges of the active surfaces of semiconductor chips, the chips are said to be semiconductor chips of the side pad type 23, 24.
Recently, a semiconductor chip of a so-called "center pad type" has been generalized, having chip pads formed along the center of active surfaces of the chips, since the center pad type is more advantageous for implementation in a high speed device. Meanwhile, BGA packages with stacked chips 20 according to the prior art, as shown in FIG. 2, have a defect in that they cannot use center pad type semiconductor chips because of the difficulty in stacking chips and the increased length of gold wires. BGA packages with stacked chips 20 are also vulnerable to a warpage phenomenon, since thermal stress can become concentrated in the upper portion of the package.
As a result, only one center pad type semiconductor chip can be implemented in a BGA package, according to the prior art. An example of a BGA package with a center pad chip is illustrated in FIG. 3.
As illustrated in FIG. 3, a BGA package with a center pad chip 30 is constructed by gluing the active surface of a semiconductor chip 32, having a chip pad 32a formed thereon, on a circuit board 31 and connecting the semiconductor chip 32 with the circuit board 31 using gold wires 33. A package mold 34 protects the semiconductor chip 32 and the gold wires 33. Solder balls 35, acting as outer connection terminals, are formed on the circuit board 31.
As explained above, stacked packages, BGA packages and center pad type semiconductor chips all have their own advantages. However, it has been considered very difficult to implement a package that combines all the advantages of the stacked packages, BGA packages and center pad type semiconductor chips, from the viewpoint of structure, manufacturing cost and process stability.

Ball grid array package with stacked center pad chips and method for manufacturing the same


A CVD process of forming a conductive film containing Ti, Si and N includes a first step of supplying gaseous sources of Ti, Si and N simultaneously to grow a conductive film and a second step of supplying the gaseous sources of Ti, Si and N in a state that a flow rate of the gaseous source of Ti is reduced, to grow the conductive film further, wherein the first step and the second step are conducted alternately.

The present invention generally relates to film forming technology and more particularly to a method of forming a conductive film by a CVD process and also a CVD apparatus.
Film forming technology is a fundamental and important technology in the fabrication process of semiconductor devices.
When fabricating a semiconductor device, it has been widely practiced to form a semiconductor film or an insulation film by a CVD (chemical vapor deposition) process. On the other hand, other processes, such as a sputtering process, have been used for forming conductive films such as wiring layers.
On the other hand, there is a growing need for the technology of forming a conductive film, such as a metal film or conductive metal compound film, as the capacitor electrode of high-dielectric or ferroelectric MIM capacitors, as in the case of a memory capacitor of a DRAM (dynamic random access memory) or a ferroelectric capacitor of a ferroelectric memory device, wherein such an MIM capacitor uses a high-dielectric film or a ferroelectric film as the capacitor insulation film in combination with the capacitor electrode.
FIG. 1 shows the construction of a typical DRAM 10 that has such an MIM high-dielectric capacitor.
Referring to FIG. 1, the DRAM 10 is constructed on a Si substrate 11 in correspondence to a device region 11A defined by a device isolation structure 12, wherein there is provided a gate electrode 14 having a polycide structure on the Si substrate 11 via an intervening gate insulation film 13. The gate electrode 14 thus formed constitutes a part of the word line of the DRAM. Further, a pair of diffusion regions 11a and 11b are formed in the Si substrate 11 at both lateral sides of the gate electrode 14, and the gate electrode 14 is covered with an interlayer insulation film 15 provided on the Si substrate 12.
On the interlayer insulation film 15, there is provided a bit line electrode in correspondence to the diffusion region 11a, wherein the bit line electrode 16 makes a contact with the diffusion region 11a at a contact hole 15A formed in the interlayer insulation film 15 via a polysilicon contact plug 16A filling the contact hole 15A.
On the interlayer insulation film 15, here is provided a memory cell capacitor 17 having an MIM structure in correspondence to the diffusion region 11b, wherein the MIM capacitor 17 makes an electrical contact with the diffusion region 11b at a contact hole 15B formed in the interlayer insulation film 15 via a polysilicon contact plug 16B provided in the contact hole 15B.
It should be noted that the memory cell capacitor 17 includes a lower electrode 17a formed on the interlayer insulation film 15 in electrical contact with the contact plug 16B, a capacitor insulation film 17b formed on the lower electrode 17a and an upper electrode 17c formed on the capacitor insulation film 17b, wherein recent, highly miniaturized DRAMs tend to use a high dielectric material such as Ta2O5 characterized by a very large specific dielectric constant, for the capacitor insulation film 17b in place of conventional SiO2 film or an ONO film, in which a SiN film is sandwiched by a pair of SiO2 films.
Further, it is possible to construct a ferroelectric memory from such a DRAM, by substituting the high-dielectric film constituting the capacitor insulation film 17b with a ferroelectric film such as PZT (Pb(Zr,Ti)O3) or SBT (SrBi2(Ta,Nb)2O9).
In the case of a high-dielectric film such as a Ta2O5 film or a ferroelectric film, it is characteristic that film formation process includes a process conducted in an oxidizing atmosphere. Further, it is generally thought essential to apply a thermal annealing process in an oxidizing atmosphere for compensating for oxygen defects that are formed in the film.
In the case of forming a Ta2O5 film by a CVD process, for example, the deposition is conducted in a 100% oxygen atmosphere or reduced pressure oxygen atmosphere at the substrate temperature of about 450° C. Thereafter, crystallization and oxygen compensation process are conducted in an oxygen atmosphere at the temperature of 650° C. A similar process is required also in the case of depositing a ferroelectric film such as a PZT film or a SBT film.
Because of this reason, the DRAMs having a high-dielectric capacitor uses Pt, or Ru or Ir, for the lower electrode, wherein it should be noted that Pt is less susceptible to oxidation while Ru or Ir forms a conductive oxide when oxidized.
However, such a high-temperature thermal process conducted in an oxidizing atmosphere can still cause the problem that oxygen in the atmosphere or in the capacitor insulation film 17b may reach the polysilicon plug 16B after penetrating through the lower electrode 17a. When this takes place, there is caused oxidation in the polysilicon plug 16B, while such an oxidation of the polysilicon plug 16B causes an increase of contact resistance and resultant decrease of the operational speed of the device. Further, such an oxidation of the polysilicon plug 16B causes another serious problem that a parasitic capacitor having a small capacitance is inserted in series to the high-dielectric capacitor when viewed in the equivalent circuit diagram. When this takes place, the increase of the capacitance of the memory cell capacitor 17, achieved by the use of the high-dielectric capacitor, is canceled out.
In order to suppress the penetration of oxygen into the contact plug associated with such a thermal annealing process in the oxidizing atmosphere, it has been proposed to use a conductive TiSiN film that contains Ti, Si and N. A TiSiN film is actually a TiN film containing Si, wherein incorporation of Si into a TiN with appropriate amount changes the film structure to an amorphous state and the amorphous film thus obtained blocks the penetration of oxygen effectively.
Even in the case such an amorphous TiSiN film is used, however, it has been difficult to block the penetration of oxygen in the case the thermal processing is conducted at the temperature exceeding 600° C. in an oxygen atmosphere, as in the case of forming the high-dielectric film such as a Ta2O5 film.

Method of forming an oxidation-resistant TiSiN film


The present invention relates to novel classes of compounds which are inhibitors of interleukin-1.beta. converting enzyme. The ICE inhibitors of this invention are characterized by specific structural and physicochemical features. This invention also relates to pharmaceutical compositions comprising these compounds. The compounds and pharmaceutical compositions of this invention are particularly well suited for inhibiting ICE activity and consequently, may be advantageously used as agents against an IL-1 mediated disease, an apoptosis mediated disease, AML, CML, melanoma, myeloma, Kaposi's sarcoma, graft vs host disease, rheumatoid arthritis, inflammatory bowel disorder, psoriasis, osteoarthritis, myeloma, apoptosis, sepsis, rheumatoid arthritis, asthma, Alzheimer's disease, Parkinson's disease, and ischemic heart disease diseases. This invention also relates to methods for inhibiting ICE activity and methods for treating interleukin-1 mediated diseases using the compounds and compositions of this invention.

Interleukin 1 ("IL-1") is a major pro-inflammatory and immunoregulatory protein that stimulates fibroblast differentiation and proliferation, the production of prostaglandins, collagenase and phospholipase by synovial cells and chondrocytes, basophil and eosinophil degranulation and neutrophil activation. Oppenheim, J. H. et al, Immunology Today, 7, pp. 45-56 (1986). As such, it is involved in the pathogenesis of chronic and acute inflammatory and autoimmune diseases. For example, in rheumatoid arthritis, IL-1 is both a mediator of inflammatory symptoms and of the destruction of the cartilage proteoglycan in afflicted joints. Wood, D. D. et al., Arthritis Rheum 26, 975, (1983); Pettipher, E. J. et al., Proc. Natl. Acad. Sci. USA 71, 295 (1986); Arend, W. P. and Dayer, J. M., Arthritis Rheum 38, 151 (1995). IL-1 is also a highly potent bone resorption agent. Jandiski, J. J., J. Oral Path 17, 145 (1988); Dewhirst, F. E. et al., J. Immunol. 8, 2562 1985). It is alternately referred to as "osteoclast activating factor" in destructive bone diseases such as osteoarthritis and multiple myeloma. Bataille, R. et al., Int. J. Clin. Lab. Res. 21(4), 283 (1992). In certain proliferative disorders, such as acute myelogenous leukemia and multiple myeloma, IL-1 can promote tumor cell growth and adhesion. Bani, M. R., J. Natl. Cancer Inst. 83, 123 (1991); Vidal-Vanaclocha, F., Cancer Res. 54, 2667 (1994). In these disorders, IL-1 also stimulates production of other cytokines such as IL-6, which can modulate tumor development (Tartour et al., Cancer Res. 54, 6243 (1994). IL-1 is predominantly produced by peripheral blood monocytes as part of the inflammatory response and exists in two distinct agonist forms, IL-1.alpha. and IL-1.beta.. Mosely, B. S. et al., Proc. Nat. Acad. Sci., 84, pp. 4572-4576 (1987); Lonnemann, G. et al., Eur.J. Immunol., 19, pp. 1531-1536 (1989).
IL-1.beta. is synthesized as a biologically inactive precursor, pIL-1.beta.. pIL-1.beta. lacks a conventional leader sequence and is not processed by a signal peptidase. March, C. J., Nature, 315, pp. 641-647 (1985). Instead, pIL-1.beta. is cleaved by interleukin-1.beta. converting enzyme ("ICE") between Asp-116 and Ala-117 to produce the biologically active C-terminal fragment found in human serum and synovial fluid. Sleath, P. R., et al., J. Biol. Chem., 265, pp. 14526-14528 (1992); A. D. Howard et al., J. Immunol., 147, pp. 2964-2969 (1991). ICE is a cysteine protease localized primarily in monocytes. It converts precursor IL-1.beta. to the mature form. Black, R. A. et al., FEBS Lett., 247, pp. 386-390 (1989); Kostura, M. J. et al., Proc. Natl. Acad. Sci. USA, 86, pp. 5227-5231 (1989). Processing by ICE is also necessary for the transport of mature IL-1.beta. through the cell membrane.
ICE, or its homologs, also appears to be involved in the regulation of programmed cell death or apoptosis. Yuan, J. et al., Cell, 75, pp. 641-652 (1993); Miura, M. et al., Cell, 75, pp. 653-660 (1993); Nett-Fiordalisi, M. A. et al., J. Cell Biochem., 17B, p. 117 (1993). In particular, ICE or ICE homologs are thought to be associated with the regulation of apoptosis in neurodegenerative diseases, such as Alzheimer's and Parkinson's disease. Marx, J. and M. Baringa, Science, 259, pp. 760-762 (1993); Gagliardini, V. et al., Science, 263, pp. 826-828 (1994). Therapeutic applications for inhibition of apoptosis may include treatment of Alzheimer's disease, Parkinson's disease, stroke, myocardial infarction, spinal atrophy, and aging.
ICE has been demonstrated to mediate apoptosis (programmed cell death) in certain tissue types. Steller, H., Science, 267, p. 1445 (1995); Whyte, M. and Evan, G., Nature, 376, p. 17 (1995); Martin, S. J. and Green, D. R., Cell, 82, p. 349 (1995); Alnemri, E. S., et al., J. Biol. Chem., 270, p. 4312 (1995); Yuan, J. Curr. Opin. Cell Biol., 7, p. 211 (1995). A transgenic mouse with a disruption of the ICE gene is deficient in Fas-mediated apoptosis (Kuida, K. et al., Science 267, 2000 (1995). This activity of ICE is distinct from its role as the processing enzyme for pro-IL-1.beta.. It is conceivable that in certain tissue types, inhibition of ICE may not affect secretion of mature IL-1.beta., but may inhibit apoptosis.
Enzymatically active ICE has been previously described as a heterodimer composed of two subunits, p20 and p10 (20 kDa and 10 kDa molecular weight, respectively). These subunits are derived from a 45 kDa proenzyme (p45) by way of a p30 form, through an activation mechanism that is autocatalytic. Thornberry, N. A. et al., Nature, 356, pp. 768-774 (1992). The ICE proenzyme has been divided into several functional domains: a prodomain (p14), a p22/20 subunit, a polypeptide linker and a p10 subunit. Thornberry et al., supra; Casano et al., Genomics, 20, pp. 474-481 (1994).
Full length p45 has been characterized by its cDNA and amino acid sequences. PCT patent applications WO 91/15577 and WO 94/00154. The p20 and p10 cDNA and amino acid sequences are also known. Thornberry et al., supra. Murine and rat ICE have also been sequenced and cloned. They have high amino acid and nucleic acid sequence homology to human ICE. Miller, D. K. et al., Ann. N.Y. Acad. Sci., 696, pp. 133-148 (1993); Molineaux, S. M. et al., Proc. Nat. Acad. Sci., 90, pp. 1809-1813 (1993). The three-dimensional structure of ICE has been determined at atomic resolution by X-ray crystallography. Wilson, K. P., et al., Nature, 370, pp. 270-275 (1994). The active enzyme exists as a tetramer of two p20 and two p10 subunits.
Additionally, there exist human homologs of ICE with sequence similarities in the active site regions of the enzymes. Such homologs include TX (or ICE.sub.rel-II or ICH-2) (Faucheu, et al., EMBO J., 14, p. 1914 (1995); Kamens J., et al., J. Biol. Chem., 270, p. 15250 (1995); Nicholson et al., J. Biol. Chem., 270 15870 (1995)), TY (or ICE.sub.rel-III) (Nicholson et al., J. Biol. Chem., 270, p. 15870 (1995); ICH-1 (or Nedd-2) (Wang, L. et al., Cell, 78, p. 739 (1994)), MCH-2, (Fernandes-Alnemri, T. et al., Cancer Res., 55, p. 2737 (1995), CPP32 (or YAMA or apopain) (Fernandes-Alnemri, T. et al., J. Biol. Chem., 269, p. 30761 (1994); Nicholson, D. W. et al., Nature, 376, p. 37 (1995)), and CMH-1 (or MCH-3) (Lippke, et al., J. Biol. Chem., (1996); Fernandes-Alnemri, T. et al., Cancer Res., (1995)). Each of these ICE homologs, as well as ICE itself, is capable of inducing apoptosis when overexpressed in transfected cell lines. Inhibition of one or more of these homologs with the peptidyl ICE inhibitor Tyr-Val-Ala-Asp-chloromethylketone results in inhibition of apoptosis in primary cells or cell lines. Lazebnik et al., Nature, 371, p. 346 (1994). The compounds described herein are also capable of inhibiting one or more homologs of ICE (see example). Therefore, these compounds may be used to inhibit apoptosis in tissue types that contain ICE homologs, but which do not contain active ICE or produce mature IL-1-.beta..
ICE inhibitors represent a class of compounds useful for the control of inflammation or apoptosis or both. Peptide and peptidyl inhibitors of ICE have been described. PCT patent applications WO 91/15577; WO 93/05071; WO 93/09135; WO 93/14777 and WO 93/16710; and European patent application 0 547 699. Such peptidyl inhibitors of ICE has been observed to block the production of mature IL-1.beta. in a mouse model of inflammation (vide infra) and to suppress growth of leukemia cells in vitro (Estrov et al., Blood 84, 380a (1994)). However, due to their peptidic nature, such inhibitors are typically characterized by undesirable pharmacologic properties, such as poor cellular penetration and cellular activity, poor oral absorption, poor stability and rapid metabolism. Plattner, J. J. and D. W. Norbeck, in Drug Discovery Technologies, C. R. Clark and W. H. Moos, Eds. (Ellis Horwood, Chichester, England, 1990), pp. 92-126. This has hampered their development into effective drugs.
Accordingly, the need exists for compounds that can effectively inhibit the action of ICE in vivo, for use as agents for preventing and treating chronic and acute forms of IL-1-mediated diseases, apoptosis-mediated diseases, as well as inflammatory, autoimmune, proliferative, infectious, or degenerative diseases.

Inhibitors of interleukin-1.beta. converting enzyme


By arranging dies in a stack such that failed cores are aligned with adjacent good cores, fast connections between good cores and cache of failed cores can be implemented. Cache can be allocated according to a priority assigned to each good core, by latency between a requesting core and available cache, and/or by load on a core.

The invention relates generally to semiconductor structures and fabrication of semiconductor chips and, in particular, to connections and logic enabling management of pooling of cache between dies in a stack of processor chips.
Multi-core processor chips can provide high performance while increasing chip area less than ganging multiple single core processor chips. However, the fabrication of multi-core processors has several challenges, some resulting from the complexity of such processors, and some resulting from spatial and layout requirements. A typical core can include central processing unit (CPU) logic and at least one cache memory. For example, cores of some multi-core processors can include level one (L1), level two (L2), and level three (L3) cache memories working at different speeds, which can provide faster access to data and enhanced processor performance. If one or more cores of a multi-core processor are defective at test, otherwise functional memory dedicated to the failed core(s) can sit unused. As a result, cache memory sharing has been pursued in single-layer or 2D packaging.
As chips grow and/or are ganged together, wire length can reach a point where latency reduces performance and/or increases power consumption. A technique developed to address wire latency is chip or die stacking, also called 3D chip or die stacking. In such stacking, one or more dies or chips are arranged to overlie one another and include features to enable components of the dies or chips to be connected, thus allowing communication between devices or components on different dies or chips. For example, connections can be established through silicon vias, solder bumps, wire bonding, and/or other arrangements and/or techniques, which can shorten effective wire length between components and/or devices. Once connected, additional materials and/or non-communication connections can be made so that the stack effectively becomes a substantially permanently connected semiconductor package. As a result, chip stacking can offer lower power consumption, reduced form factor, and reduced interface latency between components of multiple chips as compared to laying out the same chips in a common plane.

Chip stack cache extension with coherency


The present invention provides a process for the manufacture of maleic anhydride by the vapor phase catalytic oxidation of n-butane with molecular oxygen by the use of a specially prepared phosphorus vanadium-oxygen composite catalyst containing specific kind of a divalent metal. The catalyst used in the present invention is prepared from a mixture of vanadyl hydrogen orthophosphate and at least one compound selected from the group consisting of a divalent metal hydrogen orthophosphate (Divalent metal is selected from Mg, Ca, Ba, Mn, Fe, Co, Ni, Cu, and Zn.), a divalent metal ammonium orthophosphate (Divalent metal is the same as above.), and a divalent metal orthophosphate (Divalent metal is the same as above.), with the atomic ratio of the divalent metal/vanadium of 0.003-0.5, by calcining the mixture at 300.degree.-400.degree. C., and then pretreating said catalyst in an inert gas or a mixed gas containing n butane and molecular oxygen at 350.degree.-700.degree. C. Maleic anhydride can be manufactured at a high conversion, a high selectivity and a high yield according to the present invention.

1. Field of the Invention:
The present invention relates to a process for the manufacture of maleic anhydride by a vapor phase catalytic oxidation of n-butane with molecular oxygen, and, in particular, to a process for the manufacture of maleic anhydride using a phosphorus vanadium oxygen composite catalyst prepared by a specific process and containing specific metals.
2. Description of the Prior Art:
Processes for the manufacture of maleic anhydride by a vapor phase catalytic oxidation of n-butane using molecular oxygen are conventionally well known in the art. Various types of catalysts used in the processes have been proposed or reported. For example, British Patent No. 1,399,560 proposes a phosphorus vanadium-oxygen composite catalyst containing Cr, Fe, Hf, Zr, La, or Ce; U.S. Pat. No. 3,862,146 discloses a phosphorus vandium oxygen composite catalyst containing Zn, Cu, Bi, or Li; and U.S. Pat. No. 3,987,063 describes a phosphorus vanadium oxygen composite catalyst containing Co, Ni, or Cd. In addition, "Shokubai", Vol. 33, No. 2, pp 115-118 (1991) presents a report dealing with the catalytic activity of a phosphorus-vanadium oxygen composite catalyst containing Mo, Sb, Cr, Fe, As, Mn, Sn, Co, Cu, Zn, W, Ca, Mg, Na, K, or Cs. These conventional phosphorus vanadium oxygen composite catalysts containing various kinds of metals proposed or reported heretofore, however, are not satisfactory in their catalytic activity, the selectivity for maleic anhydride, and the like. Improvements in their performances are therefore desired.

Process for the manufacture of maleic anhydride


The invention provides a power saving feature in a computer system such as a desktop computer using the Windows.TM. operating system. The computer system includes one or more "sleep" buttons which selectively reduce power consumption to subsystems based on the status of various consumer devices which share the subsystems with a computer function of the system. From the user's perspective, each sleep button acts as a power switch for the computer but not for devices associated with the computer. Each sleep button transitions the computer from its normal power-on state to one or more power saving states depending on which consumer devices are active.

1. Technical Field
This invention relates generally to an apparatus and method for saving power in a computer system such as a desktop or notebook type system. More particularly, the invention provides one or more "sleep" buttons which selectively power down different subsystems in a computer system on the basis of the status of various user-controlled consumer devices.
2. Related Information
Over the past several years, the electricity consumed by desktop computer systems has generally increased due to higher processor speeds, proliferation of peripherals, the use of larger displays, and other factors. Moreover, the increase in the number of computers has caused a corresponding increase in the total amount of electricity consumed. The increased electrical consumption generally harms the environment, thus prompting the Environmental Protection Agency to encourage computer makers to design computer systems with reduced power consumption. For portable computers such as so-called laptop or notebook style computers, power consumption is also a paramount concern.
Power saving features for general purpose computer systems such as desktop and notebook computer systems are well known. Some systems rely on a power management function which automatically transitions the computer to one or more power-saving states when no activities are detected. The power saving states are characterized by reduced power consumption and a reduced state of readiness. Such systems are typically designed on the assumption that a particular computer has a fixed configuration of components and peripherals. Accordingly, such techniques are not readily useful in systems which provide a wide variety of components having different power states of their own. Moreover, the user of such systems cannot directly control the power-down or re-awakening of the system since the transitions are typically predefined based on a rigid set of parameters.
Other systems provide a "suspend" mode which, when activated, slows down or stops the CPU clock, spins down the disk drive, sets the computer monitor in a "suspend" state, saves the state of various application programs, and stops most other peripheral functions. Thereafter, any interrupt such as a keyboard or modem interrupt will immediately re-activate the entire computer and suspended application programs. Such an approach still wastes more power than is necessary, because the entire system is either on or off, and a single modem interrupt can cause the full system to be powered up even though full power is not needed to service the function of interest.
Recently, personal computer systems have begun to converge with consumer devices such as televisions, radios, CD players, answering machines, and the like. These integrated systems have increased complexity, making it more difficult to apply conventional power management techniques.
As one example, when a television receiver is integrated into a personal computer (i.e., the television display shares the computer screen with application programs), conventional power management techniques are inappropriate. In particular, the display must remain energized to support the TV function even though other subsystems of the underlying computer may not be in use. Because conventional power management functions would automatically turn off the display when the underlying computer is not being used, such conventional methods would effectively shut down the TV function while it was in use. Conversely, leaving all peripherals powered up when only the TV function is used wastes power. Providing separate "off" switches for each device or combination of devices is too confusing and still does not solve many of the aforementioned problems. Consequently, a need exists for more sophisticated power saving techniques when consumer devices are integrated into personal computer system, such that the power management features have knowledge of the applications which are currently being used.

Method and apparatus for a computer power management function including selective sleep states

Toshiba America Information Systems, Inc.


Methods and apparatus, including computer program products, for a write queue descriptor count instruction for high speed queuing. A write queue descriptor count command causes a processor to write a single word containing a queue count for each of a plurality of queue entries in a queue array cache.

Some network devices such as routers and switches have line speeds that can be faster than 10 Gigabits. For maximum efficiency the network devices should be able to process data packets, including storing them to and retrieving them from memory at a rate at least equal to the line rate. Network devices implement congestion avoidance algorithms such as Weighted Random Early Discard (WRED) to preserve chip resources and to regulate packet flow by probabilistically dropping packets as output queue lengths increase beyond predefined limits. The count of packets or buffers for each queue should be observable for all output queues.

Write queue descriptor count instruction for high speed queuing


The present invention includes an irrigation controller utilizing a “virtual” dial. In particular, the present invention contemplates an electronic programming and controlling interface that is controlled according to actuation of a simple on/off switch (i.e., a binary switch), preferably a push button. For example, in one embodiment, an irrigation controller is provided wherein a rotary dial is replaced with a circular liquid crystal display. The LCD contains segments peripherally on its screen that are energized according to the desired function selected by the user. The segment that is “on” at a particular time will correspond to visual indicia on the panel of the controller to inform the user which function is operable at that particular time. The user can then advance to the next segment on the LCD screen by pressing a button located elsewhere on the controller panel.

Most residences, office buildings, industrial complexes, golf courses, nurseries and the like include outdoor landscapes that contain grass, plants, trees, flowers etc. And in order to maintain such landscapes in an aesthetically (and safe) state, it is often necessary to ensure that such landscapes receive proper amounts of water at appropriate times of the day in particular seasons of the year.
Many users of these facilities seek to minimize the manpower necessary to ensure such proper watering schedules and do so through the use of irrigation controllers. Typically, such an irrigation controller is connected to a plurality of sprinkler assemblies located throughout a particular landscape and is then programmed so that the sprinklers are caused to go on and off at regulated times according to the programmed schedule.
The sophistication of irrigation controllers has advanced considerably over the years in response to rising demand and reliance by consumers on the advantages afforded by such irrigation controllers. This has led to increased complexity that can sometimes make the operation of an irrigation controller somewhat confusing and cumbersome. The numerous different variables that can now be adjusted in even the cheapest irrigation controller can make the programming step alone a challenging task for the user. Furthermore, due to the increased competition in the market of irrigation controllers, manufacturers are constantly seeking to introduce controller products that simplify the controller operation and yet still enable production in a cost effective manner.
One of the areas in irrigation controller design that lends itself to simplification without increasing costs or losing functionality is the elimination of rotary dials or switches that typically are used on the face of irrigation controllers. For example, many prior art controllers have a circular knob/switch on the controller face that, when rotated, adjusts the operation mode of the controller. At one location, the knob/switch may place the controller into a "time set" mode. At another location, the knob/switch may place the controller in a "manual" mode. Eliminating this knob/switch without losing the functionality of the knob/switch is desirable since it will reduce the costs of the controller and likely enhance its reliability.


An implantable neuromodulation system and method of treating a patient through neuromodulation of a patient's body tissue. The neuromodulation system includes a portable transmitter and an implantable receiver. The implantable receiver includes one or more electrodes disposed on the distal end of one or more elongated, flexible insulated leads. The transmitter is programmable with a treatment protocol to cause the transmitter to generate a pulsed, alternating magnetic field in accordance with the treatment protocol. When the transmitter is placed in close proximity to the receiver, the alternating magnetic field pulses generated by the transmitter cause the receiver to operably generate stimulating pulses delivered via the electrode(s) to the targeted tissue of the patient.

1. Field of the Invention
The present invention relates generally to nerve stimulation or neuromodulation and more particularly to implantable nerve stimulation or neuromodulation systems and methods.
2. Description of the Related Art
Urinary incontinence is a symptom that can be caused by a wide variety of conditions. Some urinary incontinence conditions are temporary and may result from urinary tract or vaginal infections, constipation, or the effects of medicine, including such medicines as diuretics, antidepressants and other drugs causing anticholinergic effects, as well as sedatives, narcotics, analgesics, etc. which can cause muscle relaxation, sedation, delirium, and/or immobility. Other urinary incontinence conditions are longer-lasting, and may even be permanent. Such longer lasting incontinence conditions may be caused by obesity, pregnancy and vaginal child birth, pelvic surgeries such as hysterectomies, trauma resulting in damage to the nerves that control the bladder, stroke, and chronic diseases that cause nerve and bladder neuropathy such as multiple sclerosis, diabetes and Parkinson's disease.
Incontinence is classified by the symptoms or circumstances occurring at the time of the urine leakage. Stress incontinence is a term used to refer to loss of bladder control resulting from poor bladder support by the pelvic muscles or by weak or damaged sphincter muscles. This condition allows urine to leak when the abdomen is stressed or strained, such as during coughing, sneezing, laughing, bending over and even walking. Urge incontinence results when the bladder contracts unexpectedly causing urine leakage. An overactive bladder may result from infection that irritates the bladder lining, nerve damage, and other conditions. Mixed incontinence is often a combination of both stress incontinence and urge incontinence. Overflow incontinence occurs when the bladder is allowed to become so full that it simply overflows. This happens when bladder weakness or a blocked urethra prevents normal emptying of the bladder. An enlarged prostate can result in such blockage. For this reason, overflow incontinence is more common in men that in women. Bladder weakness can develop in both men and women, but it happens most often in people with diabetes, heavy alcohol users, and others with decreased nerve function.
Overactive bladder ("OAB") is a combination of symptoms including urgency (the strong need to urinate), frequency (repetitive need to void) and/or urge incontinence. OAB is highly correlated with age and, for women, childbirth. OAB causes embarrassment to patients and very often negatively affects their social and sex lives. In the past, accurate data on the prevalence of OAB was unavailable partly due to the unwillingness of patients to discuss their symptoms and the market's common belief that there were no treatments. Recent epidemiological studies, however, have provided data on the prevalence of OAB symptoms in the adult population grouped according to age and gender. According to these studies 19.6 million Americans experience OAB and the incidences of OAB are projected to climb to 24.2 million by 2015. Researchers overwhelmingly report that these estimates could grossly underestimate those affected as women commonly accept OAB, secondary to childbirth, as something "to live with." Further, it is known that those affected are hesitant to discuss their symptoms with doctors as they are embarrassed by their condition and have been discouraged by the lack of solutions. As a result, less conservative studies estimate that OAB currently affects 53 million Americans.
To understand the causes of ("OAB") and the ability to treat OAB through nerve stimulation or neuromodulation, it is necessary to have a proper understanding of the urinary system and its operation.
Urine comprises waste and water removed from the blood by the kidneys. Urine flows from the kidneys downward through a pair of tubes, the ureters, to the bladder. The bladder is a balloon-like container that stores urine. Urine leaves the body through another tube, the urethra, at the bottom of the bladder.
The act of urinating is controlled by muscles that comprise the outflow controls, called sphincters, located at the base of the bladder and in the wall of the urethra, referred to as the detrusor muscles. In a healthy or normal urinary system, the sphincter muscles are constantly in a state of active contraction, except during the voluntary act of evacuation. Thus, in the contracted state, the contracted sphincter muscles close-off the neck of the bladder and the urethra, much like a tie at the base of a balloon, to prevent the flow of urine from the bladder. During urination, the sphincter muscles are relaxed thereby causing the neck of the bladder and the urethra to open. At the same time, the detrusor muscle contracts to squeeze the bladder thereby forcing the urine to evacuate the bladder. When the bladder is empty and urination is completed, the detrusor muscle returns to its normal relaxed state and the sphincter muscles again return to their normally contracted state, to close-off the neck of the bladder and urethra to prevent any further passage of urine from the bladder.
It is well known that electrical stimulation of the S2 and S3 sacral nerves can modulate the neuromuscular control of bladder function in a human. The S2 sacral nerve constitutes the main motor supply to the external sphincter muscle. Whereas the S3 sacral nerve constitutes the main motor supply to the detrusor muscle. It is also known that electrical stimulation of the tibial nerve at approximately two inches (5 cm) cephalic to the medial tibial malleolus, can stimulate the S2 and S3 sacral nerves, thereby enabling modulation of the bladder, in substantially the same way as if directly stimulating the S2 and S3 sacral nerves. Thus, modulation of the tibial nerve provides a less invasive and less costly method of achieving the same, if not better results, than the highly invasive spinal, abdominal or genito-pelvic implants which are more difficult to place, present a greater likelihood of complications, and necessarily involve higher costs.
Accordingly, there is a need for a nerve stimulation or neuromodulation system that is less invasive when compared to other neurostimulation implant procedures so as to minimize risk of complications and which is easier and less time consuming for the physician to place in the patient, but which is effective for both nerve and muscle stimulation for treatment of numerous conditions, including, but not limited to, urge incontinence, urinary frequency, non-obstructive urinary retention and interstitial cystitis, as well as for treating chronic pain, Parkinson's disease, multiple sclerosis and other neuromuscular disorders and for general muscle and joint rehabilitation.

Implantable neuromodulation system and method


A display device includes a display module configured to output a broadcast program and a channel banner list, a communication module configured to perform a data communication with an external server, a receiving unit configured to receive a channel change signal, a memory configured to store a viewing history data of a user, and a controller configured to control an operation of the display device, the controller is further configured to output a first broadcast channel banner list including a channel banner of broadcast channels received by the display device in a screen, receive a broadcast channel change signal more than a first number within a predetermined time period, output a second broadcast channel banner list having changed a size of the channel banner of the channels included in the first broadcast channel banner list.

1. Field of the Invention
The present invention relates to a technology applicable to various display devices, and more particularly, to a display device designed to change an output of a channel banner according to a use pattern of a user and a method of controlling therefor.
2. Discussion of the Related Art
A display device can receive additional information of a broadcast channel which is received via a reception unit. The additional information of the broadcast channel may include title information of the broadcast channel, program information broadcasted on the broadcast channel, and the like. The display device can generate a channel banner including the additional information of the broadcast channel and can output the channel banner in a screen. Moreover, the display device can generate a channel banner list in a manner of collecting a channel banner of channels received via the reception unit and can output the channel banner list in the screen. And, the display device can allocate and store a channel number not only on a broadcast channel but also in an application or a web page. And, the display device can perform a pairing with at least one external device. And, the display device can perform a data communication with the paired external device. For instance, the display device may correspond to a cellular phone, a smartphone, a computer, a tablet PC, a notebook, a netbook, a TV (television), other broadcast receiving device, and the like.

Display device and method for controlling the same


Ion mobility spectrometer. The spectrometer includes an enclosure for receiving a sample therewithin and an electron beam window admits an electron beam into the enclosure to ionize the sample in an ionization region. A shutter grid is spaced apart from the ionization region and means are provided for sample ion preconcentration upstream of the shutter grid. The ion preconcentration is effective to reduce space charge resulting in a lowered threshold detection level.

Ion Mobility spectrometers (IMS) have been developed for very sensitive monitoring of chemical species. An important application of the technology is its use to detect trace quantities of explosive material and chemical agents in compact devices. Trace ions of a subject material are separated by using the fact that the electrical mobility of different ion species is different. Time of flight measurements are made. Once chemical species are separated, the ionic current is measured using an electrometer.
Presently, most IMS devices use for ionizing a sample either a radioactive source (Ni63 being the most common, although T3 and Am241 are also used), UV or corona discharge. Use of more intense ionization sources could be advantageous, since the current measured by the electrometer would be larger, decreasing the detection threshold. If limited by ion recombination, the density of reactive ions (and therefore the current) is proportional to the square root of the ionization source. Increasing the ionization rate by a factor of one-thousand increases concentration of reactive ions (primary ions) by a factor of approximately thirty, which should result in a decrease in the minimum detectable limit (MDL) by a factor of thirty or higher. Moreover, there are cases (where the ions quickly form cluster ions, for example) where the ion loss is not determined by ion recombination. In this case, the ion concentration will be linear with ionization rate, and the ion concentration will be one-thousand times higher for an ionization source one-thousand times stronger.
Traditionally, the sample analyzed by IMS is on the order of a few hundred ml/min. This small sample size is partly due to the very low dose of the ionization source used in these instruments. Increasing the sample size by an order of magnitude can increase the accuracy and the sensitivity of the IMS. This increase can be achieved with the use of a more powerful ionization source such as an electron beam.
The use of more intense ionization sources for IMS has been previously considered by others. Electron beams have also been contemplated as an ionization source. In the patent literature, Vitaly Budovich (U.S. Pat. No. 5,969,349, October 1999) teaches the use of an electron beam as the ionization source. The source has a window, preferably mica, and an evacuated volume with a hot cathode or a photocathode. Hans-Rudiger Donzig (U.S. Pat. No. 6,429,426, August 2002) teaches the use of an electron beam source used to make x-rays. In this case, the electrons do not have to be extracted from the evacuated volume. More recently, Hans-Rudiger Donzig (U.S. Pat. No. 6,586,729, July 2003), teaches the use of a current controlled e-beam for the control of x-ray emission, using a sustainer (in a triode configuration). This patent also teaches a scheme for monitoring the pressure in the tube and evacuating the tube when the pressure is too high.
These patents, and in particular U.S. Pat. No. 5,969,349, teach an electron source with a cathode at a high negative potential. This high potential is needed for acceleration of the electrons using conventional acceleration technology. However, conventional technologies present issues with the size of DC power supplies (including the transformer), the size of the high voltage insulators and other issues dealing with high voltage such as arcing. Alternatives to the high voltage requirement for high energy electron beams could result in significantly more robust and compact devices.
In U.S. Pat. Nos. 5,969,349, 6,429,426 and 6,586,729, no mention is made of the possibility of using a variable strength ionization source for the optimal performance of the IMS, nor do they teach operation of IMS to handle the large space charge that is generated by a source that is much stronger than the conventional radioactive sources in IMS devices. Large space charge is not an issue with U.S. Pat. Nos. 6,429,426 and 6,586,729, due to the very low efficiency in turning electron energy into soft x-rays.
It is very important, while increasing the intensity of the ionization source, to decrease the effect of space charge in the drift region in order to take full advantage of the higher ion concentration. High space charge at the higher ion concentration limits the resolution by spreading the peaks and by ion radial loss in the drift column due to space charge.
An approach that uses nonlinear effects on mobility for chemical species separation has been proposed. This approach employs High Field Asymmetric Ion Mobility Spectrometry (FAIMS) (I. A. Buryakov, E. V. Krylov, E. G. Nazarov, U. K. Rasulev, Int. J. Mass Spectrom. Ion Processes 128 (1993) 143; R. W. Purves, R. Guevremont, S. Day, C. W. Pipich, M. S. Matyjaszczyk, Rev. Sci. Instrum. 69 (1998) 4094.)). See also, U.S. Pat. No. 5,420,424, ION MOBILITY SPECTROMETER, BL Carnahan, A. Tarassov Apr. 29, 1995. In this case, the ion separation occurs by applying a combination of DC and AC fields in the direction perpendicular to the motion of the sample gas flow. The ions are separated due to nonlinearity of the ion speed with respect to the applied electric field. A combination of DC and AC fields results in no net drift for a specific set of ions, which after separation can thus be injected into a mass spectrometer (MS). The applied electric fields are perpendicular to the direction of gas flow, and the ions are separated/removed in the direction perpendicular to the gas flow. The advantage of this scheme is that it is possible to have continuous injection into the MS (as opposed to a regular IMS that has pulsed injection of the ions of interest, known, and the product ions). However, the separation in this approach (FAIMS/MS) occurs in the drift region, and does not solve the problem of high space charge.
Alternative methods for concentrating the ions were discussed by William Blanchard (U.S. Pat. No. 4,855,595, August 1989). This patent teaches the concentration of the sample ions using electric fields in the drift region, downstream from the shutter. The issue of high space charge in the region upstream from the shutter is not addressed, nor is any preconcentration or space charge reduction upstream from the shutter. The problem is not resolved by concentrating in the drift region, since the largest space charge occurs immediately after the shutter grid, before the ions have had time to axially separate.
A model for the sheath region has been developed. The sheath region is defined as the region where species of either positive or negative charge exist, surrounding a region with very similar positive and negative ion concentrations. Results are shown in FIGS. 1a and 1b. For the case of 2 nA (FIG. 1a) (typical of present day devices with a current density on the order of 10−5 A/m2) the dimension of the space charge region (known as sheath) upstream from the shutter can be on the order of a few centimeters (IMS design used for the calculations was obtained from Analysis of a drift tube at ambient pressure: Models and precise measurements in ion mobility spectrometry, G. A. Eiceman, E. G. Nazarov, and J. E. Rodriguez, J. A. Stone, Review of Scientific Instruments 72 3610 (2001)). The distance between the shutter and the ionization region in conventional IMS systems is comparable to the sheath dimension. For this reason, these systems are not strongly affected by space charge in the ionization region. The electric field is strongest in the zone next to the shutter grid, and approaches zero at the location of the plasma zone.
If the ionization strength is increased, the sheath size is reduced. Results for the case of current density on the order of 200 nA are shown in FIG. 1b. In this case, the size of the sheath is less than 1 cm. Space charge is important in this case, and care must be taken in the latter case with the ion injection method to minimize space charge in the drift region. Conventional injection methods would result in space-charge dominated flow in the drift region, with loss of resolution and corresponding increase in Minimum Detection Level.
Present day devices utilize a relatively low radioactive source, about 10 mC (milliCuries). This ionization source produces high energy electrons with a current of about 15 pA (picoAmperes). It should be noted that these fast electrons ionize the background gas producing a swarm of electron/ion pairs, at an energy expense of ˜35 eV per electron/ion pair. With little difficulty it is possible to have an electron beam with currents of a few μA (microA), while with difficulty it is possible to have electron currents on the order of mA (milliA). This results in a very large increase in the ionization source, about 5 orders of magnitude for the case with a 1 μA (microA) beam. It should be noted that alternative ionization sources in otherwise conventional IMS devices (such as corona discharge) operate at currents on the order of a μA (microA).
In the drift region, the space charge limits the resolution of the instrument. With 2 nA current in the drift region, present day IMS have substantial space charge to result in substantial spreading of the ion cloud (and therefore loss of resolution and selectivity). With a 100 μs pulse width (corresponding to an axial cloud length of the about 1 mm), a 2 nA beam will spread about 50 μs (corresponding to about 0.5 mm axial length of the cloud). Therefore, space charge in the drift region is already important in present day devices, and needs to be addressed for devices with much higher ionization rate for improved resolution in present day devices.
Diffusion of the ions is another source of broadening. It has been known that the resolution (selectivity) limitation due to diffusion depends on the voltage applied across the drift region. For the highest voltages considered, diffusion is less important, and the spreading is the combined effect of both space charge and diffusion.
Although a large amount of literature exists on IMS devices, little is said about ion handling upstream from the shutter. In this region, high space charge results in plasma surrounded by sheaths. Improved performance of the IMS can be obtained by using innovative methods of ion injection into the drift region, including shutter grid design.
FIG. 2a shows the potential distortion, due to finite geometry effects, in the shutter region for those conditions with the shutter closed. FIG. 2b shows the electric field with the shutter open (data from Eiceman et al.). The ion reaction region is to the left of the shutter, while the drift region is to the right. The grid spacing and wire size were taken from Eiceman (0.05 mm parallel wires separated 0.5 mm). Spikes occur at the location of the parallel wires. Note the large distortion of the potential due to shutter grid geometry, and in particular, that the potential to repel the positive ions is substantially less than the applied potential. It is during transients (i.e., when the shutter is open) that the distortion effects are important in accepting ions. This is important because the ions are extracted mainly from the regions with large field distortion (the width of the cloud is about 1 mm, and the region of highly distorted fields is about 0.5 mm).


A regulator circuit and a method for compensating for sag in the output signal of the regulator circuit. A first comparator is coupled to an input of an oscillator, which oscillator outputs a clock signal and a ramp signal. In accordance with a feedback signal from the output of the regulator circuit, the clock and ramp signals of the oscillator are reset if the output signal sags to an undesirable level. The clock and ramp signals can be reset between active edges of the clock. The reset clock and ramp signals cause the regulator circuit to increase its output voltage to reduce the sag.

Switching power supplies are used in a variety of electronic products including computers, calculators, cell phones, cameras, Personal Digital Assistants (PDAs), video game controllers, etc. These types of supplies generate regulated voltages that are used to provide power for the integrated circuits contained in the electronic products. FIG. 1 illustrates a conventional switching power supply 10 that includes a switching regulator 12 having outputs coupled to the gates of switching transistors 14 and 16. A drain terminal of switching transistor 14 is coupled for receiving a source of operating potential VDD and a source terminal of switching transistor 14 is connected to a drain terminal of switching transistor 16. The common connection of the source and drain terminals of switching transistors 14 and 16 is connected to one terminal of an inductor 18. The other terminal of inductor 18 is coupled to an output 20 of switching power supply 10. Output 20 is coupled for receiving a source of operating potential VSS through a capacitor 22 and through a resistor divider network 24. Resistor divider network 24 comprises a resistor 26 having a terminal connected to output 20 and a terminal commonly connected to one terminal of a resistor 28 at a node 30. The other terminal of resistor 28 is coupled for receiving source of operating potential VSS. Node 30 is connected to an input of controller 12 and provides a feedback signal for controlling switching transistors 14 and 16.
In operation, when the output voltage drops below a predetermined value, a feedback signal from node 30 causes switching regulator 12 to generate a control signal, which in turn causes switching transistor 14 to turn on and increase the output voltage, VO, at output 20. In this configuration, the control signal is synchronous with the system clock signal. Because the control signal can last from zero seconds to a full clock period, it can begin and end within a single clock period. However, it cannot be restarted until the next clock signal. A drawback with this system is that if a transient electrical signal causes the output voltage to sag after the control signal has ended, the control signal will not compensate for the sag until the next clock signal. One way to compensate for transient electrical signals that appear in the output signal has been to include a hysteretic control circuit within the controller. Although this technique is capable of quickly compensating for transient electrical signals appearing in the output, it does so without using a clock signal. Thus, the switching frequency of the switching regulator is not constant, but varies with temperature, input voltage, and the components themselves. What's more, because the switching frequency is not constant, the hysteretic control circuitry introduces electromagnetic noise which interferes with the performance of the electronic products. This noise is referred to as Electro-Magnetic Interference (EMI).
Hence, a need exists for a switching regulator and a method for regulating its output voltage with a fast response time while operating at a constant switching frequency using a clock signal.

Method for regulating an output signal and circuit therefor

Semiconductor Components Industries, L.L.C.


A data storage system comprises a magnetic disk, an optical disk, optical disk drive units, and optical disk transport devices for transporting the optical disk to the optical disk drive units as required. The data storage system further comprises a host system for receiving and transmitting a command and data in the format of the magnetic disk and a converter for converting the command and the data between the format of the magnetic disk and that of the optical disk. The optical disk, the optical disk drive unit and the optical disk transport device are controlled by a command and data in the format of the magnetic disk of the host system.

The present invention relates to a data storage system comprising a plurality of low-bit-cost memory media such as optical disks stored therein.
Many techniques including the one disclosed in JP-A-53-23199 are known as conventional data storage systems like a library system having a plurality of data media stored therein.
In these data storage systems, a multiplicity of memory media stored therein are transported for access to a memory medium drive unit as required. Generally, however, they are controlled by a host system supporting commands for data processing and a transport system depending on the features of the media and utilizing the data stored in the memory media.

Multi-disc optical data storage system for use with a host computer for emulating a magnetic disc device


A method and apparatus are provided for direct casting molten metal to continuous strip of crystalline material by controlling the supply of molten metal to a casting vessel substantially horizontal to an adjacent moving casting roll surface, the molten metal level in the exit end being near the crest of the casting roll, separating a semi-solid cast strip substantially horizontally from near the crest of the casting roll and providing secondary cooling while transporting the separated strip to solidify the strip.

This invention relates to a method and apparatus for direct casting of metal alloys from molten metal to continuous sheet or strip product. More particularly, it relates to feeding molten metal from an exit end of a casting vessel near the top of a casting roll surface to form a continuous strip of desired thickness.
In conventional production of metal strip, such methods may include the steps of casting the molten metal into an ingot or billet or slab form, then typically includes one or more stages of hot rolling and cold rolling, as well as pickling and annealing at any of various stages of the process in order to produce the desired final strip thickness and quality. The cost of producing continuous strip, particularly in as-cast gauges ranging from 0.010 inch to 0.160 inch (0.025 to 0.40 cm) could be reduced by eliminating some of the processing steps of conventional methods. The as-cast strip could be processed conventionally, by cold rolling, pickling, and annealing to various final gauges as thin as foil, for example 0.001 to 0.12 inch (0.025 to 0.30 cm).
There is a wide variety of methods and apparatus known for the production of directly cast strip. Typically such methods are those which include spraying molten metal through a metering orifice across a gap to a rapidly moving quenching surface, such as a wheel or continuous belt; methods which partially submerge a rotating quenching surface into a pool of molten metal; methods which use horizontal link belts as quenching substrates upon which molten metal flows for solidification; and methods of vertically casting with twin casting rolls having a pool of molten metal therebetween. Direct casting of metals through an orifice has long been attempted for commercial production of strip with good quality and structure, but with little success for crystalline metal strip.
More recently, other direct casting processes have been proposed but not developed into commercial processes. For example, a process is proposed for producing cold-rolled strip or sheet of austenitic stainless steel by using a continuous caster in which a casting-mold wall is moved synchronously with the cast strip and thereafter skin pass rolling as disclosed in U.S. Pat. No. 5,045,124, issued Sep. 3, 1991. Another process is disclosed in an International Application bearing No. PCT/US88/04641, filed Dec. 29, 1988 and published Aug. 10, 1989, using a melt drag metal strip casting system wherein molten metal is delivered from a casting vessel to a single chill surface such that the strip has an unsolidified top surface which is contacted by a top roll spaced a distance substantially equal to the thickness of the strip and having a temperature which will not solidify the top surface of the metal being cast. A specific tundish having flow diverters is disclosed in an International Application No. PCT/US88/04643, filed the same date and published Oct. 19, 1989. That same process and apparatus is also disclosed in another International Application No. PCT/US90/01211, filed Mar. 14, 1990 and published Sep. 20, 1990, but further describing a grooved chill surface.
Another method is provided for directly casting molten metal from the exit end of a casting vessel onto a moving casting surface to form a continuous strip of crystalline metal using the surface tension of the molten metal for forming the top, edge, and bottom surfaces of the strip being cast with good surface quality, edges and structure. An apparatus is also provided including a casting vessel having a molten metal receiving end and an exit end from which a fully-developed uniform flow of molten metal leaves through a U-shaped structure to a moving casting surface. U.S. Pat. No. 4,678,719, issued Jul. 7, 1987, solves many problems associated with the prior art direct casting methods and apparatus such as those described above. U.S. Pat. No. 4,715,428, issued Dec. 29, 1987, describes a related method of radiantly cooling the molten metal at the exit end of the vessel.
What is still needed is a method and apparatus useful in the commercial production for direct casting strip having surface quality comparable to or better than conventionally-produced strip. Such a method and apparatus should be able to produce sheet and strip product having uniform thickness and flatness and having a smooth upper and lower surface with no porosity in the sheet. Furthermore, the method and apparatus should minimize or eliminate any handling damage of the strip after separation from the casting surface and be suitable for casting continuous strip in gauges ranging from 0.010 to 0.160 inch (0.025 to 0.40 cm). The direct cast strip should have good surface quality, edges and structure and properties at least as good as conventionally-cast strip and be suitable for the casting of carbon steels and stainless steels.

Method and apparatus for direct casting of continuous metal strip


Nucleotide phosphonate esters characterized by the presence of an ester linked group which is bonded to the phosphorus atom of phosphonate nucleotide analogs are disclosed. The analogs comprise an ester bond that is hydrolyzed in vivo to yield a corresponding phosphonate nucleotide analog. Methods and intermediates for their synthesis and use are described.

The present invention relates to nucleotide analog esters, their pharmaceutically acceptable acid addition salts, processes for their production, and to their use.
Compounds related to the nucleotide analogs of the present invention may be found in: U.S. Pat. Nos. 5,043,339, 5,108,994 and 5,166,198; EP 206 459; EP 253 412; EP 269 947; EP 270 885; EP 319 228; EP 343 133; EP 398 231; EP 404 296; EP 465 297; EP 468 119; EP 468 866; EP 479 640; EP 481 214; EP 494 370; EP 531 597; PCT/GB91/01171; PCT/US92/01020; PCT/US92/05208; WO 91/19721; Bronson et al., Bioorg Medicinal Chem Lett (1992) 2:685-690; Bronson et al., J Med Chem (1989) 32:1457-1463; Bronson et al., Nucleotide Analogs as Antiviral Agents, ACS Symposium Series 401, J. C. Martin, Ed., p. 72-87, American Chemical Society, Washington, D.C. (1989); Colla, et al., J Med Chem (1983) 26:602-604; Curley, et al., Antiviral Res (1990) 14:345-356; De Clercq, et al., Nature, (1986) 323:464-467; Farrow, et al., J Med Chem (1990) 33:1400-1406; Farquhar, et al., J. Pharm Sci (1983) 72:324-325; Freed, et al., Biochem Pharmacol (1989) 19:3193-3198; Freeman, et al., J Med Chem (1992) 35:3192-3196; Gabrielsen, B., et al., Antiviral Res Supp I (1992) 17:149; Gumport, et al., Proc Natl Acad Sci (1971) 2559-2563; Juodka, et al., Coll Czech Chem Commun (1974) 39:963-968; Kim, et al., Bioorg Medicinal Chem Lett (1992) 2:367-370; Kim, et al., Tet Lett (1992) 33:25-28; Kim, et al., J Med Chem (1990) 33:1207-1213; Kumar, et al., J Med Chem (1990) 33:2368-2375; McGuigan, et al., Antiviral Chem Chemother (1993) 4:97-101; McGuigan, et al., Antiviral Res (1991) 15:255-263; Rosenberg, et al., Coll Czech Chem Commun (1988) 53:2753-2777; Rosenberg, et al., Coll Czech Chem Commun (1988) 52:2792-2800; Rosenberg, et al., Coll Czech Chem Commun (1988) 52:2801-2808; Starrett, et al., Antiviral Res (1992) 19:267-273; Yu, et al., J Med Chem (1992) 35:2958-2969; Wolff-Kugel, et al., Tet Lett (1991) 32:6341-6344.
A characteristic of nucleotide analogs or nucleotides having a phosphonate or a phosphate group is the presence of one or two negative charges associated with the phosphorus group at physiologic pH. Workers believe the charge associated with moieties such as phosphate or phosphonate groups generally limit oral bioavailability by limiting passive diffusion through the intestine membrane (Liebman, et al., J. Biol. Chem. (1955) 216:823-830; Roll, et al., J Biol Chem, (1956) 220:439-444; Srivastava, et al., Bioorg Chem (1984) 12:118-129; Palu, et al., Antiviral Res (1991) 16:115-119; Sastry, et al., Mol Pharmacol (1992) 41:441-445). Workers often administer these compounds parenterally to obtain therapeutic serum or intracellular levels.


A fully differential peak detection circuit includes programmable sensitivity and an autozero function. The peak detector has a fully differential charge-coupled analog signal path. The entire analog signal path is autozeroed upon enable and/or in response to sensing a logic zero at the output, where the logic zero follows a logic one. The peak detector includes a differential gain stage for receiving an analog input signal. The differential gain stage includes offset error compensation. The offset error compensation is selected upon enable and/or in response to an output signal of the peak detection circuit and automatically zeros an offset error voltage in response to a predetermined logic state of the output signal. The output of the gain stage is provided to a comparator stage. A plurality of capacitors coupled to the comparator stage stores a predetermined voltage for setting a sensitivity of the peak detector. The sensitivity is programmable during an autozero sequence by applying a predetermined voltage to the plurality of capacitors.

One form of a peak detector is a circuit that senses the amplitude of a time varying signal and provides a logic one output if the amplitude is greater than a predetermined value and a logic zero output if the amplitude is less than the predetermined value. One common implementation of the peak detector comprises an amplifier with feedback and an integrator. Various sources for error are associated with the amplifier and noise can be introduced into different parts of the circuit. Offset error compensation is used to reduce some of the effects of the error. However, in some applications the peak detector will not function reliably because the signal level is smaller than the potential offsets and errors in the amplifier. Also, the integrator can introduce error and/or uncertainty in the logic output.
Therefore, it is desirable to provide a peak detector circuit that can convert small signal levels and compensate for error.

Circuit and method for peak detection of an analog signal


A case for dissipating heat from an electronic device is provided. The case includes an electronic circuit board with a heat generating electronic component installed thereon. A shield is positioned over the electronic component to protect it from electromagnetic interference. The shield includes an aperture through its top surface. A heat transfer conduit is molded into and through the aperture to contact the top surface of the heat generating electronic component. Outer housing, which is made of a thermally conductive material, is placed into contact with the top surface of the heat transfer conduit which extends outside the shield. As a result, heat is dissipated from the electronic component and through the housing of the electronic device via the heat transfer conduit while shielding the electronic component from electromagnetic interference.

The present invention relates generally to electronic devices, integrated circuit component and cases for housing such components. More specifically, the present invention relates to apparatuses for dissipating heat generated by such devices.
In the electronics and computer industries, it has been well known to employ various types of electronic component packages and integrated circuit chips, such as the PENTIUM central processing unit chip (CPU) manufactured by Intel Corporation and RAM (random access memory) chips. These integrated circuit chips have a pin grid array (PGA) package and are typically installed into a socket which is soldered to a computer circuit board. These integrated circuit devices, particularly the CPU microprocessor chips, generate a great deal of heat during operation which must be removed to prevent adverse effects on operation of the system into which the device is installed. For example, a PENTIUM microprocessor, containing millions of transistors, is highly susceptible to overheating which could destroy the microprocessor device itself or other components proximal to the microprocessor.
In addition to the PENTIUM microprocessor discussed above, there are many other types of semiconductor device packages which are commonly used in computer equipment, for example. Recently, various types of surface mount packages, such as BGA (ball grid array) and LGA (land grid array) type semiconductor packages have become increasingly popular as the semiconductor package of choice for computers.
The aforementioned electronic components are commonly employed in electronic devices, such as computers and cellular phones. These devices are being manufactured smaller and smaller and include faster and faster electronic components therein. As a result, heat generation and overheating continues to be a serious concern while the sizes of the devices get smaller. Therefore, problems arise as to effectively cooling the small electronic components within small and cramped environments within the device. Typical cooling solutions are not preferred because they are large and, as a result, consume large spaces within an already cramped electronic device case. Also, these small devices, such as a cellular phone or laptop computer, must address the competing demands of high power requirements, smaller battery sizes and associated power limitations and overall device case size. Therefore, active cooling solutions, such as powered fans and the like, are not desirable.
Moreover, electromagnetic interference shielding is also often required to ensure proper operation of the electronic device. However, the use of EMI shielding, which typically encases the electronic component within the device to be protected, obstructs proper installation and use of effective solutions for cooling the same electronic component. Therefore, there are competing needs for EMI shielding and effective thermal solutions within electronic devices, particularly in device cases where space is at a premium.
In view of the foregoing, there is a demand for an electronic device case that has a low profile and is net-shape moldable from a thermally conductive material so complex geometries for optimal cooling configurations can be achieved. There is also a demand for an electronic device case that provides passive heat dissipation for a heat generating electronic component to be cooled. There is further demand for an electronic device case to provide both EMI shielding and superior heat dissipation.
The present invention preserves the advantages of prior art heat sink assemblies for electronic devices and cases for such devices. In addition, it provides new advantages not found in currently available assemblies and overcomes many disadvantages of such currently available assemblies.
The invention is generally directed to the novel and unique electronic device case that includes an improved heat dissipating system for cooling heat generating devices and circuit boards housed therein. The case of the present invention enables the cost-effective cooling of electronic devices while realizing superior thermal conductivity and improved electromagnetic shielding.
In accordance with the present invention, a case for dissipating heat from an electronic device is provided. The case includes an electronic circuit board with a heat generating electronic component installed thereon. A shield is positioned over the electronic component to protect it from electromagnetic interference. The shield includes an aperture through its top surface. A heat transfer conduit is molded into and through the aperture to contact the top surface of the heat generating electronic component. Outer housing, which is made of a thermally conductive material, is place into contact with the top surface of the heat transfer conduit which extends outside the shield so that heat may be dissipating from the electronic component and through the housing via the heat transfer conduit while shielding the electronic component from electromagnetic interference.
The preferred embodiment of the present invention is assembled by routing an aperture through a shield that is positioned over an electronic component installed on a circuit board within the electronic device. The shield acts as a shroud around the electronic component to shield it from electromagnetic interference (EMI). However, such a shield effectively encases the electronic component making access thereto for dissipating heat very difficult, if not impossible. For example, an EMI shield makes the attachment of a heat sink assembly to the electronic component very difficult. Further, the EMI shield encasement prevents air flow to the electronic component for cooling.
A heat transfer conduit is molded into and through the aperture in the EMI shield using a thermally conductive composition, preferably a polymer composite material that is net-shape and injection moldable. The heat transfer conduit is molded to be long enough to extend through the aperture in the EMI shield to communicate with the top surface of the heat generating electronic component. The opposing end of the heat transfer conduit extends outside the EMI shield for exposure to air, such as convecting air within a computer case. The housing of the computer case is also thermally conductive and is preferably positioned to contact the end of the heat transfer conduit that extends outside of the EMI shield to further transfer and conduct the heat from the electronic component.
The present invention may alternatively include a thermally conductive housing that directly contacts the heat generating component within an electronic device case to enhance cooling thereof. Further, raised structures or protrusions on housing may also be employed to ensure thermal contact between the thermally conductive housing and the heat generating electronic component.
It is therefore an object of the present invention to provide an electronic device case that enhances the dissipation of heat from a heat generating electronic component housed therein.
It is an object of the present invention to provide an electronic device case that directly provides heat dissipation for a heat generating electronic component housed therein.
It is a further object of the present invention to provide an electronic device case that passively provides heat dissipation for a heat generating electronic component housed therein.
Another object of the present invention is to provide an electronic device case that simultaneously provides electromagnetic shielding and heat dissipation for an electronic component.
It is a further object of the present invention to provide an electronic device case that is injection moldable of a thermal composite material into complex geometries to enhance thermal dissipation.

Thermally conductive electronic device case


A method for measuring the concentration of harmful gases in flue gases through a heat-producing plant that includes a combustion space and a device located downstream of the combustion space, the device includes tubes, through which for instance water, steam or air may pass in order to be heated by heat transfer from flue gases formed during the combustion. In a region near the tube device, at least one beam of ultraviolet light is emitted from a light emitter at one side of a flue gas duct to a light receiver located at the opposite side of the duct, which light emitter is connected to a spectrometer cooperating with a computer unit, in which spectrometer the light is divided spectrally.

Simultaneous production of heat and steam by combustion of a so-called bio-fuel, i.e., a solid fuel consisting of wood or biomass, has lately become more and more common, inter alia due to the facts that such a production is power-efficient, shows endurance in the long run, may be based on domestic raw materials and gives a minimal influence on the environment. However, it has turned out that the combustion of bio-fuel is a process that in some respects is more complicated and difficult to handle than the combustion of other solid fuels, such as coal. One complication is that the ashes from a bio-fuel has another composition and other melting properties than, e.g., coal ash. Inter alia, this difference involves costly problems with corrosion and ash deposition on the tubes included in existing superheating plants. Thus, serious high temperature corrosion has been observed in the major part of combined power and heating plants in Sweden after some years of operation with 100% bio-fuel. The problems may become particularly accentuated when to the fuel are added such materials as demolition timber and sorted waste of different types. In practice, the corrosion manifests itself in that the usually high-alloyed, and thereby expensive, superheater tubes are coated with stout, strongly adhering layers or deposits of ash, at the same time as the tube surface underneath is exposed to corrosive melts which give rise to a loss of metal.
Among experts, unanimity reigns that chlorine constitutes the main corrosion accelerator in the above-mentioned context. A conventional theory is that chlorine is transported into the ash deposit on the superheater tubes in the form of gas phase potassium chloride (KCl), alternatively as very small aerosols of potassium chloride that have condensed immediately upstream of the superheater device. Thereafter, a reaction with sulphur takes place on the tube surface in the ash deposit, thereby forming potassium sulphate and free chlorine, which in this form is very corrosive. Albeit this theory is plausible, in practice great difficulties exist not only to verify this theory but also to take measures to solve the problem, above all due to the lack of a suitable measuring technique. It is true that in SE 8502946-0, it is in general terms described how photo-spectrometry may be utilized to determine certain parameters, e.g., the concentration, for gaseous substances that occur in such combustion processes that are performed at high temperatures, but in this case the technique is primarily focussed on measuring in flames, and the document does not contain any instructions as to how the technique would, in practice, be used for measurements in plants of the type presented in the preamble.
Quite generally, in heat-producing plants occur, besides the above-mentioned corrosion problems, also other similar problems that are caused by the presence of gaseous metal chlorides or metals in elementary form. Hence, in the plants may be included also other arrangements than merely superheater devices comprising sets or packages of tubes, through which for instance air is circulated in order to be heated (in practice, such arrangements usually consist of air pre-heaters or so-called economizers). When metals, such as heavy metals in the form of zinc and lead in gaseous form, are carried by the flue gases and hit the arrangements, they are deposited on the surfaces of the tubes, thereby forming deposits that are not necessarily corrosive, but that deteriorate the heat transfer from the flue gases to the medium that circulates within the tubes.

Method and a device for measuring, by photo-spectrometry, the concentration of harmful gases in the fumes through a heat-producing plant


Methods and devices are provided for decreasing the likelihood of damage to a holstered gun. The devices include a combination of a holster, having a retaining cavity, and a removable insert which modifies the characteristics of the retaining cavity. In preferred embodiments, the removable insert decreases the likelihood of damage to a holstered gun which may arise from contact between the gun and a surface of the retaining cavity.

Holsters are used to restrain and carry hand-held weapons such as guns and knives, as well as tools such as hammers and other hand tools, flashlights, and measurement and display devices such as radar guns and distance measuring devices. For the sake of simplicity, the term "gun" will sometimes be used herein to refer to all objects capable of being carried in a holster. Similarly, a gun at least partially in a holster may be said to be "holstered", and the act of placing the gun at least partially in the holster may be referred to as "holstering" the gun.
Holsters are frequently sized and shaped so as to include a retaining cavity in which a portion of a gun, when holstered, rests. The retaining cavity generally conforms somewhat to the shape of the portion of the gun within the cavity. The cavity generally maintains a fixed shape regardless of whether it currently contains a gun. In this manner known holsters promote quick and easy insertion and removal of a gun. Many holsters are formed from leather because leather is relatively stiff, yet lightweight and easy to work with and shape. Because leather is generally softer than the surface of the gun, leather holsters are less likely to damage a gun than a holster made from a harder material.
In some instances it may be advantageous to manufacture a holster in which at least a portion of the retaining cavity comprises a surface which is harder than leather, and possibly harder than the surface of the gun. Such holsters may be less expensive to manufacture or maintain, might be more weather resistant, and may be stronger than, for example, comparable all leather holsters. The additional strength might be useful in applications involving increased stress on the holster. One type of holster where a retaining cavity is substantially metal includes holsters mounted to a motorcycle to facilitate the carrying of radar guns. In that instance metal holsters are used to help prevent theft of, and/or accidental damage to a holstered gun. A typical holster for radar, laser and other hand-held measurement devices is depicted in prior art FIG. 1.
One possible problem with metal holsters is that they may tend to damage the outer surface of a holstered gun. This problem exists for any holster wherein a portion of the retaining cavity comprises a material which is harder than the surface of the gun to be holstered. Another possible problem with metal holsters is that their retaining cavities tend to conform poorly to the shape of the gun being holstered. Poorly conforming holsters tend to allow the gun to move or rattle within the holster, with such movement or rattling increasing the likelihood of damage to the gun. Such movement or rattling may also generate unwanted noise. The use of softer materials in forming the retaining cavity may also be problematic in that such materials tend to rot, weaken, or otherwise breakdown after prolonged exposure to the elements.
In an attempt to overcome some of these problems, the prior art metal holster of FIG. 1 uses a spray felt to cover the inside of the holster. Although the spray felt provides for a softer retaining cavity surface, the use of spray felt is disadvantageous for a number of reasons. Among other things it is difficult, if not impossible, to provide spray felt having a shape which conforms to that of a gun to be holstered. Another disadvantage is that the felt tends to suffer damage under prolonged use and exposure. Thus, the holster functionality decreases over time and may ultimately result in having to replace the holster.
Thus there is a continuing need for methods and devices to provide holsters comprising softer, better conforming retaining cavities, without decreasing the durability or useable life of the holsters.


A method for drilling formations below the bottom of a body of water includes disposing a drilling system on the bottom of the body of water. The formations are drilled by rotating a first drill rod having a first core barrel latched therein and advancing the drill rod longitudinally. At a selected longitudinal position, an upper end of the first drill rod is opened and a cable having a latching device at an end thereof is lowered into the first drill rod. The winch is retracted to retrieve the first core barrel. The first core barrel is laterally displaced from the first drill rod. A second core barrel is inserted into the first drill rod and latched therein. A second drill rod is affixed to the upper end of the first drill rod. Drilling the formation is then resumed by longitudinally advancing and rotating the first and second drill rods.

1. Field of the Invention
The invention relates generally to the field of drilling Earth formations below the bottom of a body of water. More specifically, the invention relates to remotely operated drilling devices that are positioned on the sea floor.
2. Background Art
Drilling through Earth formations located below the bottom of a body of water generally require the use of drilling equipment deployed from a barge or ship, and in the case of deep water sites, from a drillship or semisubmersible floating drilling platform. Such drilling is a complicated and expensive operation, particularly in deep water where a drilling riser must be extended from the floating drilling structure to the sea floor to provide a return conduit for drilling fluid from the well as it is drilled. In addition to cost, drilling using such riser is not well suited to drilling tasks requiring precise control of bit weight, stability (motion compensation) of the drill string and exact positioning of tools within the borehole. Positioning of the surface vessel over the borehole on the seabed is of critical importance when a drilling riser is used. Multiple anchors or dynamic positioning are required to maintained the required degree of positional stability of the floating drilling platform. The in-water weight of the riser limits the water depth in which risers can be deployed. Floating drilling platforms capable of handling long risers for deep water are by necessity very large vessels.
In an attempt to minimize the above noted aspects of drilling in deep water, several seafloor based drilling systems have been developed and are in current operation. "BMS #1" and "BMS #2" are owned by JOGMEC (Japan), "PROD" is owned by Benthic Geotech Pty. Ltd. (Australia), "MeBo" is owned by the University of Bremen (Germany) and "RD2" is owned by the British Geologic Survey. The forgoing remotely operated systems have proven effective in drilling into the seabed, particularly in deep water. Because they all use a flexible umbilical rather than a drilling riser, the in-water weight of such systems is typically less than 20 tons and as a result drilling operations can be conducted from vessels as small as 50 m in length. Station keeping (positional stability) requirements for the vessel are much less stringent than for floating drilling platforms using riser, and an operational watch circle of about 20% of the water depth is adequate in most cases. Because the drilling systems are disposed on the water bottom while drilling and are necessarily heavy enough to provide sufficient reactive mass to advance the drill string, the stability of tools disposed within the borehole is excellent. Complete decoupling of drill string motion from ship motion is accomplished.
When used to drill core samples of the subsurface below the bottom of a body of water, all of such remotely operated water bottom drilling systems depend upon rod coring methodology. A core barrel is disposed at the bottom of a drill string. The core barrel is typically about the same length as one segment of drill pipe or string. As the borehole is extended by drilling, the core barrel is filled and then must be retrieved from the borehole to extract the core therein. Such methodology requires the retrieval of the entire drill string each time a core barrel is recovered. While the foregoing method operated from a water bottom disposed drilling unit eliminates the drill pipe riser extending from the floating drilling platform to the water bottom, the extensive tool handling required by such coring techniques results in a significant operational time to complete boreholes deeper than about 30 meters. A single 100 meter deep borehole using rod coring with standard 3 meter core barrels and drill rods requires more than two thousand tool handling operations and over one hundred hours complete. The extensive time on station and the large number of tool manipulations make rod core drilling impractical for all but shallow holes in deep water.
There exists a need for a water bottom based drilling unit that can obtain core samples with reduced tool handling an operating time.

Remotely operated water bottom based drilling system using cable for auxiliary operations