The present invention provides a purified polynucleotide encoding a novel receptor, designated NTR3, which belongs to the TNF receptor gene superfamily; to purified NTR3 polypeptide molecules; to antibodies that bind NTR3; to materials comprising such molecules; and to methods of using such molecules.

The present invention is in the field of recombinant genetics. In particular, the present invention relates to a novel receptor NTR3, belonging to the TNF-receptor supergene family and nucleic acid molecules encoding the same. The invention also relates to vectors, host cells, anti-NTR3 antibodies and recombinant method NTR3 receptor polypeptides. The invention also relates to the use of the recombinant NTR3 polypeptide to identify putative binding proteins. In addition, provided for are methods and reagents for the diagnosis of diseases associated with abnormal NTR3 or abnormal expression of its putative ligand, and methods and pharmaceutical composition(s) for the treatment of diseases associated with abnormal NTR3 or abnormal expression of NTR3 and/or its ligand. The invention also discloses pharmaceutical compositions for use in the treatment of these diseases.
Technical advances in the identification, cloning, expression and manipulation of nucleic acid molecules have greatly accelerated the discovery of novel therapeutics based upon deciphering the human genome. Rapid nucleic acid sequencing techniques can now generate sequence information at unprecedented rates, and coupled with computational analyses, allow the assembly of overlapping sequences into entire genome and the identification of polypeptide-encoding regions. Comparison of a predicted amino acid sequence against a database compilation of known amino acid sequences can allow one to determine the extent of homology to previously identified sequence and/or structure landmarks. Cloning and expression of a polypeptide-encoding region of a nucleic acid molecule provides a polypeptide product for structural and functional analysis. Manipulation of nucleic acid molecules and encoded polypeptides to produce variants and derivatives thereof may confer advantageous properties on a product for use as a therapeutic.
However, in spite of the significant technical advances in genome research over the past decade, the potential for development of novel therapeutics based on the human genome is still largely unrealized. While a number of genes encoding potentially beneficial protein therapeutics, or those encoding polypeptides which may act as xe2x80x9ctargetsxe2x80x9d for therapeutic molecules, have been identified using recombinant DNA technology, the structure and function of a vast number of genes in the genome of mammals are yet unknown.
Tumor necrosis factor (TNF) was first identified in the serum of mice and rabbits which had been infected with bacillus of Calmette and Guerin (BCG) and which had been injected with endotoxin. TNF activity in the serum of these animals was recognized on the basis of its cytotoxic and anti-tumor activities. This TNF activity, referred to as TNF-xcex1, is produced particularly by activated monocytes and macrophages, and has been implicated in normal growth processes as well as in a variety of diseases. Following the discovery of TNF-xcex1, independent research led to the identification of another cytokine associated with inflammatory responses, lymphotoxin-xcex1 (LT-xcex1), which was shown to be produced exclusively by lymphocytes. LT-xcex1 was subsequently shown to be 30% homologous with TNF-xcex1, and was renamed TNF-xcex2. It is now clear that TNF-xcex1 and TNF-xcex2 are members of a gene family that includes yet another member termed LT-xcex2 (Browning et al., Cell 72:847-856, 1993). The three genes are tightly linked within the MHC complex and show similar organization. Moreover, the biologically active forms of TNF-xcex1 and TNF-xcex2 are homotrimers and share many of the same biological activities including competing for the same cell-surface receptors (Agarwal et al., Nature 318:665-667, 1985). Two distinct but structurally homologous receptors have been identified, and each has been shown to bind both the ligands and mediate their effects.
However, it has been recognized that TNFs are only representative members of the rapidly expanding supergene family that includes TNF-xcex1, TNF-xcex2/lymphotoxin-xcex1 (LT-xcex1), lymphotoxin-xcex2(LT-xcex2), FasL, CD40L, CD30L, CD27L, 4-1BBL, and TNF-related apoptosis-inducing ligand (TRAIL), RANKL, GITRL and TNF-2. See generally, Orlinick et al., Cell Signal, 10(8):543-551, 1998. The distinctive but overlapping cellular responses induced by members of the TNF family of ligands following their interaction(s) with their cognate cell-surface receptors result in clearly defined developmental and regulatory changes in cells of the lymphoid, hematopoietic, and other lineages. For example, the TNF family of ligands are involved in growth regulation and differentiation of cells which are involved in inflamation, immune processes and hematopoiesis (Bayert, R. and Fiers, W., Tumor Necrosis Factor and Lymphokines in: Cytokines eds. Anthony Mire-Sluis and Robin Thorpe, Academic Press San Diego, Calif., 1998). The TNF family of ligands activates the immune defenses against parasites, and acts directly and/or indirectly as a mediator in immune reactions and inflammatory processes. However, administration of TNF and/or other members of the TNF family can also be accompanied by harmful phenomena such as shock and tissue damage (Bayert, R. and Fiers, W., supra). The main physiological role of the TNF family of ligands is likely the activation of first-line reaction of an organism to microbial, parasitic, viral, or to mechanical stress and cancer. For example, TNF-related apoptosis-inducing ligand (TRAIL) has been demonstrated to induce apoptosis of a number of different types of cancer cells as well as virally infected cells.
Furthermore, a number of observations have also led to the conclusion that the TNF family of ligands are also involved in a variety of pathological conditions including cachexia, toxic shock syndrome, inflammatory diseases such as rheumatoid and osteoarthritis, in the lethality resulting from graft-versus-host reaction (GVHR)(Bayert, R. and Fiers, W., supra), rapid necrosis of tumors, apoptosis, immunostimulation and resistance to parasites and viruses.
Like other cytokines, the members of the TNF family of ligands act via specific cell-surface receptors. The receptors, with two exceptions, are type 1 membrane associated proteins. The sequence homology amongst them is almost entirely confined to the extracellular domain. For example two TNF receptors have been cloned which differ in size and in binding affinity (Bayert, R. and Fiers, W., supra). Both receptors bind TNF-xcex1 and TNF-xcex2. The two receptors consist of extracellular domains which bind TNF and are homologous for 28%, single transmembrane domains, and intracellular domains which are totally different and does not contain any recognizable structure associated with any particular function. Based on similarities in their extracellular domains, these receptors belong to a receptor gene superfamily that includes the low-affinity nerve growth factor (NGF) receptor, the Fas antigen, the human B-lymphocyte activation molecule CD40, CD27, 4-1BB, PV-T2, CD30, TNFR-RP, TRAIL-R, PV-A53R, RANK, GITR, and the OX40 antigen found on activated T-cells (Smith et al., Cell, 76(6):959-962, 1994; Baker and Reddy, Oncogene, 12(1):1-9, 1996).
In addition to the membrane associated receptor molecules described above, a number the receptors belonging to the TNF-receptor supergene family exist as soluble ligand binding proteins. Many of the soluble forms of the transmembrane receptors were subsequently identified as containing only the extracellular ligand binding domain(s) of the receptors. For example, a soluble form of TNF receptor has been found in urine and serum (see U.S. Pat. No. 5,843,789 and Nophar et al., EMBO J. 9(10):3269-3278, 1990), and have been shown to arise by proteolytic cleavage of cell surface TNF-receptors (Wallach et al., Agents Actions Suppl., 35:51-57, 1991). These soluble forms of receptor molecules have been implicated in the modulation of TNF activity by not only interfering with TNF binding to its receptor, but also by stabilizing the TNF structure and preserving its activity, thus prolonging some of its effects (Aderka et al, Cytokine and Growth Factor Reviews, 7(3):231-240, 1996).
The activity of members of the TNF family of ligands are tightly regulated at the levels of secretion and receptor expression. Additional regulatory mechanisms are provided by action of specific inhibitory proteins present on cell surfaces and in biological fluids. While some of these inhibitory proteins have been identified as soluble forms of receptor molecules, the identity of many of these cytokine regulatory proteins are as yet unknown. However, abnormalities in the production of these substances might contribute to the pathophysiology of a variety of diseases including immune and neoplastic diseases. Besides their role, in regulating cytokine activity in vivo, these regulatory molecules hold significant potential for therapeutic use as very specific inhibitors/anti-cytokine agents, and as indicators in diagnosis and assessment of immune function and growth parameters in a variety of autoimmune and malignant diseases.
Because of the crucial role that members of the TNF family of ligands and their receptors (membrane-associated and soluble) play in the immunological system and in a variety of disease processes, a need exists to identify and characterize novel members of these families, for use to improve diagnosis and therapy.
The present invention relates to a novel serine/threonine kinase family and uses thereof. More specifically, the present invention relates to novel NTR3 nucleic acid molecules and encoded polypeptides, and uses thereof.
The invention provides for an isolated nucleic acid molecule comprising a nucleotide sequence selected from the group consisting of:
(a) the nucleotide sequence set forth in SEQ ID NO: 1;
(b) a nucleotide sequence encoding the polypeptide set forth in SEQ ID NO: 2;
(c) a nucleotide sequence which hybridizes under moderately or highly stringent conditions to the complement of (a) or (b), wherein the encoded polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2; and
(d) a nucleotide sequence complementary to any of (a) through (c).
The invention also provides for an isolated nucleic acid molecule comprising a nucleotide sequence selected from the group consisting of:
(a) a nucleotide sequence encoding a polypeptide that is at least about 70, 75, 80, 85, 90, 95, 96, 97, 98, or 99 percent identical to the polypeptide set forth in SEQ ID NO: 2, wherein the polypeptide has an activity of the encoded polypeptide set forth in SEQ ID NO: 2 as determined using a computer program selected from the group consisting of GAP, BLASTP, BLASTN, FASTA, BLASTA, BLASTX, BestFit, and the Smith-Waterman algorithm;
(b) a nucleotide sequence encoding an allelic variant or splice variant of the nucleotide sequence set forth in SEQ ID NO: 1, wherein the encoded polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2;
(c) a nucleotide sequence of SEQ ID NO: 1, (a), or (b) encoding a polypeptide fragment of at least about 25 amino acid residues, wherein the polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2;
(d) a nucleotide sequence encoding a polypeptide that has a substitution and/or deletion of 1 to 251 amino acid residues set forth in any of SEQ ID NOS: 1-2 wherein the encoded polypeptide has an activity of the polypeptide set forth in SEQ ID NO:2;
(e) a nucleotide sequence of SEQ ID NO: 1, or (a)-(d) comprising a fragment of at least about 16 nucleotides;
(f) a nucleotide sequence which hybridizes under moderately or highly stringent conditions to the complement of any of (a)-(e), wherein the encoded polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2; and
(g) a nucleotide sequence complementary to any of (a)-(e).
The invention further provides for an isolated nucleic acid molecule comprising a nucleotide sequence selected from the group consisting of:
(a) a nucleotide sequence encoding a polypeptide set forth in SEQ ID NO: 2 with at least one conservative amino acid substitution, wherein the encoded polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2;
(b) a nucleotide sequence encoding a polypeptide set forth in SEQ ID NO: 2 with at least one amino acid insertion, wherein the encoded polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2;
(c) a nucleotide sequence encoding a polypeptide set forth in SEQ ID NO: 2 with at least one amino acid deletion, wherein the encoded polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2;
(d) a nucleotide sequence encoding a polypeptide set forth in SEQ ID NO: 2 which has a C- and/or N-terminal truncation, wherein the encoded polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2;
(e) a nucleotide sequence encoding a polypeptide set forth in SEQ ID NO: 2 with at least one modification selected from the group consisting of amino acid substitutions, amino acid insertions, amino acid deletions, C-terminal truncation, and N-terminal truncation, wherein the polypeptide has an activity of the encoded polypeptide set forth in SEQ ID NO: 2;
(f) a nucleotide sequence of (a)-(e) comprising a fragment of at least about 16 nucleotides;
(g) a nucleotide sequence which hybridizes under moderately or highly stringent conditions to the complement of any of (a)-(f), wherein the encoded polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2; and
(h) a nucleotide sequence complementary to any of (a)-(e).
The invention also provides for an isolated polypeptide comprising the amino acid sequence selected from the group consisting of:
(a) the mature amino acid sequence set forth in SEQ ID NO: 2 comprising a mature amino terminus at residue 1, and optionally further comprising an amino-terminal methionine;
(b) an amino acid sequence for an ortholog of SEQ ID NO: 2, wherein the polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2;
(c) an amino acid sequence that is at least about 70, 75, 80, 85, 90, 95, 96, 97, 98, or 99 percent identical to the amino acid sequence of SEQ ID NO: 2, wherein the polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2 as determined using a computer program selected from the group consisting of GAP, BLASTP, BLASTN, FASTA, BLASTA, BLASTX, BestFit, and the Smith-Waterman algorithm;
(d) a fragment of the amino acid sequence set forth in SEQ ID NO: 2 comprising at least about 25 amino acid residues, wherein the polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2;
(e) an amino acid sequence for an allelic variant or splice variant of either the amino acid sequence set forth in SEQ ID NO: 2, or at least one of (a)-(c) wherein the polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2.
The invention further provides for an isolated polypeptide comprising the amino acid sequence selected from the group consisting of:
(a) the amino acid sequence set forth in SEQ ID NO: 2 with at least one conservative amino acid substitution wherein the polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2;
(b) the amino acid sequence set forth in SEQ ID NO: 2 with at least one amino acid insertion, wherein the polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2;
(c) the amino acid sequence set forth in SEQ ID NO: 2 with at least one amino acid deletion, wherein the polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2;
(d) the amino acid sequence set forth in SEQ ID NO: 2 which has a C- and/or N-terminal truncation, wherein the polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2; and
(e) the amino acid sequence set forth in SEQ ID NO: 2, with at least one modification selected from the group consisting of amino acid substitutions, amino acid insertions, amino acid deletions, C-terminal truncation, and N-terminal truncation, wherein the polypeptide has an activity of the polypeptide set forth in SEQ ID NO: 2.
Also provided are fusion polypeptides comprising the polypeptide sequences of (a)-(e) above of the preceding paragraphs.
The present invention also provides for NTR3 analogs consisting of conservative and non-conservative amino acid substitutions within SEQ ID NO: 4.
The present invention also provides for an expression vector comprising the isolated nucleic acid molecules set forth herein, recombinant host cells comprising recombinant nucleic acid molecules set forth herein, and a method of producing a NTR3 polypeptide comprising culturing the host cells and optionally isolating the polypeptide so produced.
A transgenic non-human animal comprising a nucleic acid molecule encoding a NTR3 polypeptide is also encompassed by the invention. The NTR3 nucleic acid molecules are introduced into the animal in a manner that allows expression and increased levels of the NTR3 polypeptide, which may include increased circulating levels. The transgenic non-human animal is preferably a mammal.
Also provided are derivatives of the NTR3 polypeptides of the present invention.
Additionally provided are selective binding agents such as antibodies and peptides capable of specifically binding the NTR3 polypeptides of the invention. Such antibodies and peptides may be agonistic or antagonistic.
Pharmaceutical compositions comprising the nucleotides, polypeptides, or selective binding agents of the present invention and one or more pharmaceutically acceptable formulation agents are also encompassed by the invention. The pharmaceutical compositions are used to provide therapeutically effective amounts of the nucleotides or polypeptides of the present invention. The invention is also directed to methods of using the polypeptides, nucleic acid molecules, and selective binding agents. The invention also provides for devices to administer a NTR3 polypeptide encapsulated in a membrane.
The NTR3 polypeptides and nucleic acid molecules of the present invention may be used to treat, prevent, ameliorate, diagnose and/or detect diseases and disorders, including those recited herein. Expression analysis in biological, cellular or tissue samples suggests that NTR3 polypeptide may play a role in the diagnosis and/or treatment of diseases wherein injury that is mediated by member of the TNF ligand family including rheumatoid arthritis; osteoarthritis; rheumatoid spondylitis; gouty arthritis; inflammatory bowel disease; adult respiratory distress syndrome (ARDS); psoriasis; Crohn""s disease; allergic rhinitis; ulcerative colitis; anaphylaxis; contact dermatitis; asthma; antiviral therapy including those viruses sensitive to TNFxcex1 inhibitionxe2x80x94HIV-1, HIV-2, HIV-3, cytomegalovirus (CMV), influenza, adenovirus, and the herpes viruses including HSV-1, HSV-2, and herpes zoster; muscle degeneration; cachexia; Reiter""s syndrome; type II diabetes; bone resorption diseases; graft vs. host reaction; ischemia reperfusion injury; atherosclerosis; brain trauma; Alzheimer""s disease; multiple sclerosis; cerebral malaria; sepsis; septic shock; toxic shock syndrome; fever and mylagias due to infection. This expression can de detected with a diagnostic agent such as NTR3 nucleotide.
The invention encompasses diagnosing a pathological condition or a susceptibility to a pathological condition in a subject caused by or resulting from abnormal levels of NTR3 polypeptide comprising determining the presence or amount of expression of the NTR3 polypeptide in a sample; and comparing the level of said polypeptide in a biological, tissue or cellular sample from either normal subjects or the subject at an earlier time, wherein susceptibility to a pathological condition is based on the presence or amount of expression of the polypeptide.
The present invention also provides a method of assaying test molecules to identify a test molecule which binds to a NTR3 polypeptide. The method comprises contacting a NTR3 polypeptide with a test molecule and to determine the extent of binding of the test molecule to the polypeptide. The method further comprises determining whether such test molecules are agonists or antagonists of a NTR3 polypeptide. The present invention further provides a method of testing the impact of molecules on the expression of NTR3 polypeptide or on the activity of NTR3 polypeptide.
Methods of regulating expression and modulating (i.e., increasing or decreasing) levels of a NTR3 polypeptide are also encompassed by the invention. One method comprises administering to an animal a nucleic acid molecule encoding a NTR3 polypeptide. In another method, a nucleic acid molecule comprising elements that regulate or modulate the expression of a NTR3 polypeptide may be administered. Examples of these methods include gene therapy, cell therapy, and anti-sense therapy as further described herein.
In another aspect of the present invention, the NTR3 polypeptides may be used for identifying NTR3 polypeptide binding partners (xe2x80x9cNTR3 ligandsxe2x80x9d or xe2x80x9cNTR3 binding partnersxe2x80x9d). Various forms of xe2x80x9cexpression cloningxe2x80x9d have been extensively used to clone receptors for protein or co-factors. See, for example, Simonsen and Lodish, Trends in Pharmacological Sciences, 15: 437-441, 1994, and Tartaglia et al., Cell, 83:1263-1271, 1995. The isolation of the NTR3 ligand(s) or NTR3 binding partner(s) is useful for identifying or developing novel agonists and antagonists of the NTR3 polypeptide-signaling pathway.
Such agonists and antagonists include soluble NTR3 ligand(s), anti-NTR3 selective binding agents (such as NTR3 antibodies and derivatives thereof), small molecules, peptides or derivatives thereof capable of binding NTR3 polypeptides, or antisense oligonucleotides, any of which can be used for potentially treating one or more diseases or disorders, including those recited herein.
In certain embodiments, a NTR3 polypeptide agonist or antagonist may be a protein, peptide, carbohydrate, lipid, or small molecular weight molecule which, interacts with NTR3 polypeptide to regulate its activity.
The NTR3 polypeptide can be used for identifying ligands thereof. Various forms of xe2x80x9cexpression cloningxe2x80x9d have been used for cloning ligands for receptors. See e.g., Davis et al., Cell, 87:1161-116, 1996. These and other NTR3 ligand cloning experiments are described in greater detail herein. Isolation of the NTR3 ligand(s) allows for the identification or development of novel agonists and/or antagonists of the NTR3 signaling pathway. Such agonists and antagonists include NTR3 ligand(s), anti-NTR3 ligand antibodies and derivatives thereof, small molecules, or antisense oligonucleotides, any of which can be used for potentially treating one or more diseases or disorders, including those recited herein.

Nucleic acids encoding NTR3, a member of the TNF-receptor supergene family


A method for automatically generating a network subnet configuration, monitors IP Address Resolution Protocol (ARP) frames on the network and builds and maintains a table which includes a list of learned subnets, the ports or forwarding domain associated with each of the learned subnets and a mask associated with each learned subnet for identifying hosts belonging to the subnet. The from and to IP addresses from intercepted IP ARP frames are examined to determine if the IP addresses belong in any of the learned subnets. If neither IP address belongs to an existing learned subnet a new learned subnet is established. The subnet includes the common prefix bits of both IP addresses, a mask identifying those bits and the port over which the ARP frame was received. If only one IP address belong to a learned subnet, the mask associated with that subnet is modified to include the common prefix bits of both IP addresses and the forwarding domain is adjusted. If the two IP addresses belong to different learned subnets, the two subnets are combined.

In medium to large size bridged IP networks hosts belonging to a substantial number of different subnets communicate with hosts belonging to their subnet. In most networks hosts belonging to the same subnet are typically connected to a small percentage of the total number of ports. This topology characteristic contributes to broadcast storms and/or network instability when IP broadcast frames are indiscriminately transmitted. Prior art networks have avoided this problem by configuring the network bridges in advance to direct IP broadcast frames to only those ports associated with the subnet address associated with the source host of the IP broadcast message.
While this solution works to eliminate the problem described above, it introduces another which is just as burdensome. In order to be effective the prior art solution requires intervention by a network administrator or the like each time a host is added to the network or when a host is moved from one port to another. In other words the solution requires advance configuration before the network is established and more significantly reconfiguration each time a change in the network takes place.

Method for forwarding broadcast packets in a bridged IP network

International Business Machines Corporation


A method for joining sections of densified ceramics, and ceramics to carbon omprising the steps of: placing a preceramic polymer between bodies of the materials to be joined, applying mechanical force thereto, and heating to a temperature sufficient to convert the preceramic polymer to constituents of the materials to be joined thus bonding the materials, and cooling to room temperature.

1. Field of Invention
The invention relates to a method of joining densified bodies of a ceramic to a ceramic or to carbon using a polymer which converts on pyrolysis to the constituents of the materials being joined. The bonding is carried out at lower temperatures than prior art joining techniques.
2. Description of Prior Art
Bates et al, U.S. Pat. No. 4,921,554 discloses a joining method for alpha-silicon carbide which is practiced when the bodies to be joined are green bodies.
Gupta, U.S. Pat. No. 4,487,644 discloses the joining of silicon carbide when the silicon carbide is silicon rich (at least 8% excess silicon). The joining is accomplished at temperatures between 1,500.degree. C. and 1,800.degree. C.
Coes, U.S. Pat. No. 4,070,197 discloses a joining method which uses a slip containing alpha-silicon carbide of a composition which matches the two alpha-silicon carbide pieces to be joined.
Haley, U.S. Pat. No. 4,419,161 discloses a joining method which can be used on either green bodies or fully dense pieces of alpha-silicon carbide. The pieces are joined with a metal boride such as molybdenum boride.
P/N 2,015,910 (Great Britain) discloses the use of molybdenum disilicide and a binder mixed together as a powder to form alpha-silicon carbide. Joining is achieved at temperatures above 2030.degree. C.

Method for joining ceramic to ceramic or to carbon

The United States of America as represented by the Secretary of the Army


A method for fabricating a flash memory cell is provided. After an ONO dielectric layer is formed on a first conductive layer over a tunnel oxide layer, a second conductive layer is formed on the ONO dielectric layer. Then, patterning the second conductive layer to form a periphery region comprising an exposed portion of a semiconductor substrate and a memory cell region comprising the left second conductive layer. During the present process, the ONO dielectric layer is protected from being exposed in various solvents and gases with the second conductive layer. Thus, a flash memory cell with a high-quality ONO gate dielectric layer, without increasing complexity of the process and additional masks, is obtained.

1. Field of the Invention
The present invention relates to a method for fabricating a non-volatile memory cell, and more particularly to a method for fabricating a flash memory cell.
2. Description of the Prior Art
With enlargement of an application field such as a portable telephone and digital still camera, an EEPROM (Electrically Erasable and Programmable Read Only Memory) has rapidly come into wide use. The EEPROM, which permits electrical simultaneous erase of data, is called a flash EEPROM.
The EEPROM is a non-volatile semiconductor memory device which stores digital information with two or more values according to whether or not a prescribed quantity of charges is stored and reads the digital information by a change in the conduction of a channel region corresponding to the quantity of charges.
For the conventional flash EEPROM device, each memory cell is based on a MOS transistor element (called a floating-gate transistor) composed of a tunnel oxide layer, a floating gate, a gate dielectric layer with an oxide/nitride/oxide (ONO) structure, a control gate, a source region and a drain region. The floating gate is so named due to the fact that it is physically but not electrically isolated from all the other conductive elements in the flash EEPROM device. The floating gate is located beneath the control gate and isolated by the gate dielectric layer from the control gate. The control gate is electrically connected to one word line of the flash EEPROM device.
However, in the conventional method for fabricating a flash EEPROM cell, after the ONO gate dielectric layer is deposited, a first polysilicon layer and the tunnel oxide layer on the periphery region are removed by patterning the ONO gate dielectric layer with a photolithography and etching method. Then, a gate oxide layer and a second polysilicon layer are formed on the periphery region and on the ONO gate dielectric layer of a memory cell region. As a consequence, the ONO gate dielectric layer is exposed in various solvents and gases. For example, the ONO gate dielectric layer would be exposed in an acidic solution for stripping a photoresist, a purified purge gas/or a purified solvent used in surface clean process and H2O/or oxygen gas used in a thermal oxidation for the formation of the gate oxide layer of the periphery region. Thus, many adverse effects are caused on the ONO gate dielectric layer.
Moreover, in order to prevent the loss of the ONO gate dielectric layer, the surface clean process prior to the formation of the gate oxide layer of the periphery region is significantly limited. Hence, the gate oxide layer of the periphery region is also disadvantageously influenced.
Accordingly, it is an intention to provide a method for fabricating a flash memory cell with a high-quality gate dielectric layer, which can overcome the above drawbacks.

Method for fabricating a flash memory cell


A method for inhibiting the premature polymerization of styrenic monomers is disclosed wherein the method comprises adding to said monomers a combination of:                (A) at least one inhibitor that is a sulfonic acid compound in a concentration sufficient to initiate cationic polymerization of said styrenic monomers at any point of the manufacturing or purification process and cause a resulting temperature increase; and        (B) at least one amine in a concentration sufficient to reduce said cationic polymerization and said temperature increase;        whereby an uncontrolled exothermic reaction between said sulfonic acid compound and said styrenic monomers will be prevented.

1. Field of the Invention
The present invention is directed to an improvement in a method for the inhibition of the polymerization of styrenic monomers wherein the inhibitor comprises a sulfonic acid.
2. Description of Related Art
Many ethylenically unsaturated monomers undesirably polymerize at various stages of their manufacture, processing, handling, storage, and use. Polymerization, such as thermal polymerization, during their purification results in the loss of the monomer, i.e., a lower yield, and an increase in the viscosity of any tars that may be produced. The processing and handling of the higher viscosity tars then requires higher temperature and work (energy cost) to remove residual monomer.
Polymerization can also result in equipment fouling and losses in production efficiency owing to the deposition of polymer in or on the equipment being used. These deposits must be removed from time to time, leading to additional loss in production of the monomer.
A wide variety of compounds has been proposed and used for inhibiting uncontrolled and undesired polymerization of ethylenically unsaturated monomers. However, many of these compounds have not been fully satisfactory.
U.S. Pat. No. 2,867,672 discloses that the polymerization of uninhibited styrene condensing in liquid form on the surfaces containing the vapor space above the liquid level of the main body of styrene in a tank may be minimized, by spraying the surfaces enclosing the vapor space with a styrene polymerization inhibitor.
U.S. Pat. No. 4,086,147 discloses a process for the distillation of readily polymerizable vinyl aromatic compounds comprising subjecting a vinyl aromatic compound to elevated temperatures in a distillation system in the presence of a polymerization inhibitor comprising m-nitro-p-cresol.
U.S. Pat. No.4,468,343 discloses a compound and a process for utilizing the compound to prevent the polymerization of vinyl aromatic compounds, such as styrene, during heating. The composition includes effective amounts of 2,6-dinitro-p-cresol and either a phenylenediamine or 4-tert-butylcatechol respectively, to act as a polymerization co-inhibitor system in the presence of oxygen.
U.S. Pat. No. 5,254,760 discloses the inhibition of the polymerization of a vinyl aromatic compound, such as styrene, during distillation or purification by the presence of at least one stable nitroxyl compound together with at least one aromatic nitro compound.
U.S. Pat. No. 5,290,888 discloses a process for stabilizing an ethylenically unsaturated monomer or oligomer from premature polymerization whereby a stabilizing amount of an N-hydroxy substituted hindered amine is added to said polymerizable monomer or oligomer. The ethylenically unsaturated monomer or oligomer encompasses vinyl monomers or oligomers bearing at least one polymerizable moiety. The N-hydroxy substituted hindered amine is said to inhibit premature polymerization in the liquid and/or vapor phase.
U.S. Pat. No. 5,446,220 discloses methods for inhibiting the polymerization of vinyl aromatic monomers in oxygen-free processing systems. These methods comprise adding from 1 to about 10,000 parts per million parts monomer of a combination of a dinitrophenol compound, a hydroxylamine compound and a phenylenediamine compound. Preferably, 2-sec-butyl-4,6-dinitrophenol or 4,6-dinitro-o-cresol are used in combination with bis-(hydroxypropyl)hydroxylamine and N,N′-di-sec-butyl-p-phenylenediamine.
U.S. Pat. No. 5,932,735 discloses that selected derivatives of 1-oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidine are effective as inhibitors to prevent the premature polymerization of acrylic and methacrylic acids, their esters, their amides, vinyl acetate and acrylonitrile in the presence of water.
U.S. Pat. No. 6,143,205 discloses a mixture for inhibiting the premature polymerization of monomers that contains (A) vinyl-containing monomers, and (B) an effective amount of a mixture of (I) from 0.05 to 4.5% by weight, based on the total mixture (B), of at least one N-oxyl compound of a secondary amine which carries no hydrogen atoms on the .alpha.-carbon atoms and (ii) from 99.95 to 95.5% by weight, based on the total mixture (B), of at least one nitro compound.
U.S. Published Application No. 2004/0147797 discloses a process for inhibiting the polymerization of an aromatic vinyl compound which is capable of efficiently inhibiting the polymerization of an aromatic vinyl compound not only in an initial stage but also over a long term in the stage of producing, purifying, storing or transporting the aromatic vinyl compound, and which is said to be excellent in handling. The process comprises adding 2-nitrophenol compound in combination with a sulfonic acid compound to the aromatic vinyl monomer during the stage of producing, purifying, storing or transporting the aromatic vinyl compound.
The foregoing are incorporated herein by reference in their entirety.

Means for controlling the exothermic reaction of styrenic monomers with sulfonic acids


A self-calibrating laser accelerometer system that continuously removes bias errors from acceleration measurements under dynamic operating conditions has a frame with a pair of essentially identical mass modulated accelerometers positioned within the frame. Each accelerometer includes a proof mass mounted to the sensing element frame by a flexure suspension. The proof mass is arranged to rotate about an output axis in response to acceleration of the sensing element frame along an input axis. The first proof mass includes a secondary mass that is movable between a first stable position on a first side of the output axis and a second stable position on a second side of the output axis to provide mass modulation of the first proof mass and to provide a selectively reversible polarity to the input axis and to provide self-calibration of bias.

Pendulous Integrating Gyro Accelerometers (PIGAs) and Specific Force Integrating Receivers (SFIRs) are very high accuracy accelerometers primarily used in strategic missile guidance systems. A pendulous accelerometer is based on the principle that an acceleration that displaces a suspended mass can be determined from the angle of displacement. These accelerometers have bias and scale factor performance that are one to two orders of magnitude more accurate than conventional navigation-grade accelerometers such as Northrop Grumman's A4 and SiAc accelerometers. PlGAs and SFIRs, on the other hand, are two orders of magnitude more expensive and have lower reliability, and therefore have high life cycle cost. Alternate, lower cost accelerometers such as vibrating beam accelerometers (VBAs) with improved reliability have been under development as replacements for PlGAs and SFIRs for more than two decades. While a considerable investment continues to be made in these alternate strategic-grade accelerometer technologies, none have achieved the technical readiness level to be deployed.
A variety of Helium-Neon laser accelerometers, based on laser gyroscope technology, in which the internal cavity length, and therefore the frequency of the laser, is a function of acceleration have also been proposed in the past as replacements for PlGAs and SFIRs. In general, cavity length based laser accelerometers measure the full acceleration range with proof mass displacements of less than one wavelength to avoid mode hopping. For a 633 nm laser wavelength the full range displacement of the cavity length is less than 0.32 μm. This displacement corresponds to a full range acceleration of 20 times the acceleration of gravity. The dynamic range of the accelerometer is required to be greater that 107. For the accelerometer to have bias stability and repeatability of less than 2 μg the cavity length must be stable and repeatable over temperature to less than 3×10−14 meters or 0.00003 Å. If the laser body is fabricated from a material such as Zerodur, which has a coefficient of thermal expansion between 0.02 and 0.1 ppm/° C. and the cavity lengths are 10 cm; then the thermal gradient between the two cavities, used to provide common mode rejection of ambient temperature change, would need to be less than 1.5×10−5 to 3×10−6° C. This extreme sensitivity of the accelerometer bias to thermal gradients is one of the principal reasons for prior laser accelerometers not meeting the bias stability and repeatability required for strategic applications.

This patent is subject to a terminal disclaimer.

Self-calibrating laser semiconductor accelerometer

Northrop Grumman Guidance and Electronic Co, Inc.


An array of SONOS memory cells includes: a) a pair of spaced, adjacent SONOS gates atop a silicon substrate within an array area; b) a trench between the gates, the trench having opposing downwardly elongated sidewalls and a base, the sidewalls being doped with a conductivity enhancing impurity of a first conductivity type to define separated source/drain diffusion regions in between and adjacent the respective gates of the pair, the trench being filled with an effectively electrically insulating material; c) a word line commonly interconnecting the adjacent SONOS gates of the pair; and d) separate bit lines separately electrically engaging the separated diffusion regions of the pair. LDD regions are also included. A method of producing such a construction is disclosed.

Typical semiconductor memory utilized during microprocessor operation is volatile. That is in the case of power interruption, the data stored in the semiconductor memory is typically completely lost. One way to circumvent this problem is to provide separate backup of the memory, such as battery power or capacitor storage. An alternate technique would be to make the memory fundamentally non-volatile. This option is highly desirable because non-volatile semiconductor memories would not only withstand power interruption, but also would be stored or shipped without being energized.
Typical prior art non-volatile memory cells are charge-trapping devices. Examples includes floating-gate memory devices wherein charge is stored in an isolated conductor, commonly referred to as a "floating-gate", in a field effective transistor (FET) device. Other charge-storage devices are constructed to store charge in insulator bulk traps in FET constructions. Examples includes metal-nitride-oxide-semiconductor (MNOS); metal-alumina-oxide-semiconductor (MAOS); metal-alumina-semiconductor (MAS); and silicon-oxide-nitride-oxide-semiconductor (SONOS) memory cells. This invention is specific to SONOS memory technology.
SONOS technology has existed since the late 1960's, but has not been widely used because of other apparent fundamental problems, such as data retention, process control issues, etc. Drawbacks of non-volatile semiconductor memories, such as SONOS cells, includes process complexity and cell size in comparison with a more conventional volatile dynamic random access memory (DRAM) type memory cell. Virtual ground architecture has been used in SONOS memories to reduce cell size to near theoretical limits. The use of SONOS with virtual ground has, however, been limited by the technological problems described above and by charge-disturb problems.
FIG. 1 shows a prior art circuit schematic for a SONOS virtual ground array of cells, while FIGS. 2 and 3 illustrate a top and sectional cut, respectively, of a portion of the FIG. 1 virtual ground SONOS array. FIG. 1 illustrates four SONOS memory cells 10, 11, 12 and 13, each consisting of a single SONOS memory transistor. Looking specifically to transistor 10, such is comprised of a bulk substrate portion 14 and includes a pair of source/drain diffusion regions 15, 16, a gate dielectric layer 17 and a polysilicon gate 18. Substrate 14 would be of a semiconductor material, typically comprising silicon, while dielectric region 17 would be formed of an oxide-nitride-oxide (ONO) construction. Thus, in combination with the polysilicon of gate 18, a silicon-oxide-nitride-oxide-semiconductor (SONOS) transistor is provided. Field oxide regions 19 and 20 and adjacent insulating oxide regions 21 and 22 provide electrical isolation from adjoining devices. An overlying polysilicon word line 23 provides electrical connection to gate 18.
Many memory cells, including some non-volatile memory cells, enable sharing of source/drain diffusion regions among an adjacent pair of transistors. This enables increased circuit density. Such sharing is not, however, possible with the illustrated virtual ground SONOS cell because of the need for isolated source/drain diffusion areas between adjacent transistors. Specifically, adjacent SONOS transistors 10 and 11 require separate and electrically isolated adjacent bit lines 24 and 25.
Because of this isolated source/drain requirement, the virtual ground SONOS cell size is significantly larger when compared to other memories. Specifically referring to FIG. 3, the length direction of the cell consists of one isolation space, two diffusions, and a gate resulting in a length of four times the minimum photolithographic masking feature size, which is referred to in FIG. 3 as .lambda.. Accordingly, the maximum length dimension of the illustrated cell is 4.lambda., providing a cell area of 8.lambda..sup.2. On the other hand, a typical floating-gate non-volatile memory cell has a theoretical cell size of 4.lambda..sup.2, again where .lambda. is the minimum lithographic feature size.
Certain SONOS and MNOS memory cells have been constructed which enable sharing of source/drain diffusion regions between adjacent transistors. Such a construction does, however, require an additional transistor, referred to as a "select transistor", to prevent charge stored in the oxide-nitride-oxide from being disturbed. An example of such
prior art is shown by Nozaki et al., "A 1-Mb EEPROM With MONOS Memory Cell For Semiconductor Disk Application", IEEE Journal Of Solid-State Circuits, Vol. 26, No. 4, pp. 497-501 (April 1991).

Array of non-volatile sonos memory cells


Epitaxial layers of II-VI semiconductors in-situ doped with high concentrations of a stable acceptor-type impurity and capped with a diffusion-limiting layer, when subjected to a rapid thermal anneal at a temperature between 700 and 950 degrees C., exhibit a high conversion of the impurities to acceptors, sufficient to render the layers p-type.

This invention relates to II-VI semiconductor compounds, and more particularly relates to epitaxial layers of such compounds having high concentrations of acceptor-type impurities, and also relates to a process for producing such layers.
As is known, semiconductors are characterized as either n-type or p-type, depending upon whether the predominant carriers in the material are electrons or holes. As is also known, semiconductors can be rendered n-type or p-type by substituting impurity atoms (dopants) for atoms of the host lattice which have a different valence. Donor-type impurities are those which give electrons, and thus render the host material n-type, while acceptor-type impurities are those which receive electrons, and thus render the host p-type.
Successful doping to obtain or enhance n-type or p-type conductivity depends not only upon the ability to introduce a sufficient amount of the proper dopant into the semiconductor material, but also upon the ability to position the dopant atoms in the proper substitutional sites within the material's crystal lattice where they can give or receive electrons.
Dopants which do not readily assume the proper substitutional sites in sufficient number can be activated, i.e., converted to donors or acceptors, e.g., by a thermal anneal of the doped semiconductor material.
Another important consideration is the presence of other impurities in the semiconductor material which are, or are capable of assuming, an opposite conductivity type than that intended, thus compensating the effect of the dopant. Thus, it is actually the net donor or acceptor concentration which determines the overall conductivity of the material.
Semiconductors which can easily be rendered either n-or p-type, such as Si, from Group IVA of the Periodic Table, and GaAs, a III-V compound, so-called because it is made up of elements from Groups IIIA and VA of the Periodic Table, can be converted to devices such as diodes by doping adjacent regions p-and n-type to form pn junctions.
II-VI compounds such as ZnS and ZnSe are of interest for such devices because of their relatively wide band gaps. For example, being able to form a doped junction in an epitaxial layer of ZnSe could result in a blue-emitting LED or laser.
However, in practice, it has proved extremely difficult to obtain stable p-type ZnSe epitaxial layers. While a sufficient amount of dopant can usually be introduced into the layers, it is either difficult to convert sufficient numbers of the dopant atoms into acceptors, or the acceptors are unstable. For example, lithium-doped epitaxial layers of ZnSe can be converted to p-type material (defined herein as a material having a net acceptor concentration greater than 1.times.10**14 acceptors or holes per cc)., but lithium is unstable because of its tendency to diffuse, even at relatively low temperatures.
Nitrogen would be a more stable acceptor than lithium, and can be doped into ZnSe in situ in high concentrations (10**19/cc) using metal organic chemical vapor deposition (MOCVD). However, only a small fraction of it (up to 1.times.10**14/cc) can be activated.
Greater success has been achieved using chemical beam epitaxy (CBE). That is, starting with an as-grown dopant concentration of about 10**19, a net acceptor concentration in the range of 10**16 to 10**17 has been achieved. However, the technique requires relatively expensive equipment and the conversion efficiency is relatively low.
Dopants are usually activated by a carefully controlled thermal treatment such as a furnace anneal, which allows the dopant ions to relax into the correct substitutional sites in the host lattice.
Rapid thermal annealing (RTA) has been employed as an alternative to furnace annealing to activate shallow acceptor implants of N in ZnSe heteroepitaxial layers on GaAs, in order to minimize degradation of the material by interdiffusion. In addition, a diffusion-limiting capping layer of SiO.sub.2 or Si.sub.3 N.sub.4 has been employed as further protection from degradation. Samples annealed at 600 degrees C. and above did not exhibit p-type behavior. Also, no evidence of N acceptors was observed in the PL spectra. Samples annealed at 500 degrees C. showed evidence of N acceptor in the PL spectra, but were not p-type. "Rapid Thermal Annealing and Ion Implantation of Heteroepitaxial ZnSe/GaAs", B. J. Skromme et al., Bellcore, MRS Proceedings, 1989.

Method of producing epitaxial layers of II-VI semiconductors with high acceptor concentrations

FSS DIG. 3;DIG. 63;DIG. 64;DIG. 95;DIG. 99


A semiconductor-based device includes a channel layer, which includes a distal layer and a proximal layer in contact with the distal layer. The distal layer supports at least a portion of hole conduction for at least one p-channel component, and the proximal layer supports at least a portion of electron conduction for at least one n-channel component. The proximal layer has a thickness that permits a hole wave function to effectively extend from the proximal layer into the distal layer to facilitate hole conduction by the distal layer. A method for fabricating a semiconductor-based device includes providing a distal portion of a channel layer and providing a proximal portion of the channel layer.

Newer types of substrates can be used as replacements for traditional silicon wafers to improve silicon-based electronic device performance. For example, wafers that have a silicon-germanium (SiGe) alloy layer can provide improved channel-layer performance in a strained-silicon layer grown on a relaxed, i.e., relatively strain-free, SiGe layer. Strained silicon can provide improved minority carrier mobility for a surface-channel layer in, for example, metal-oxide-semiconductor (MOS) field-effect transistors (FET).
The carrier mobility of the silicon channel layer generally increases with the level of strain in the layer. The level of strain is determined by the lattice mismatch with the underlying relaxed SiGe layer. The lattice mismatch, in turn, is determined by the Ge concentration of the relaxed SiGe layer. That is, the lattice spacing of a relaxed SiGe layer generally increases with increasing Ge concentration.
Thus, as the Ge concentration in a relaxed SiGe substrate layer is increased, the electron mobility in the overlying strained-silicon channel layer generally increases. The electron mobility generally saturates beyond a Ge concentration of approximately 20 atomic %, but the hole mobility continues to increase as the Ge concentration rises.
The behavior of electron and hole mobility is of particular significance, for example, in the performance of an inverter, one of the basic building blocks of integrated circuit devices. An inverter includes both an NMOS (i.e., n-channel) and PMOS (i.e., p-channel) transistor, and the inverter delay is dependent upon both the NMOS and PMOS transistor drive currents. With mobility enhancements of the electron and hole charge carriers, the drive current increases, and the inverter stage delay decreases.
An inverter delay is a function of both the NMOS and PMOS device transconductance. The delay can be described as:       t    p    ≈                    C        L            2                  (                        1                      K            P                          +                  1                      K            n                              )      where Ki=CvsatCoxWi, "i" represents p or n, and tp is the total inverter delay time. The delay is related to the ability of the NMOS and PMOS transistors to drive the inverter capacitance, CL. Kp and Kn are, respectively, related to the transconductance of the PMOS and NMOS transistors. C is a constant, Vsat is the saturation velocity of the carrier in the channel, Cox is the gate capacitance per unit area, and Wi is the width of the corresponding NMOS or PMOS transistor (i.e., the width of the gate).
The NMOS and PMOS transistors of a conventional Si inverter can be designed to provide approximately equal driving capabilities by appropriately adjusting the widths of the devices. In this case, the following expression aids in an estimate of improvement in inverter performance:             t      p        ≈                  B        2                          (                              1                                          e                p                                                          ω                p                                              +                      1                                          e                n                                                          ω                n                                                    )              ,where B is a constant, ep is the enhancement factor in PMOS drive current due to channel improvement relative to a standard silicon component (e.g., through use of strained-silicon), en is the enhancement factor in NMOS drive current, ωp is any relative width change in the PMOS transistor (new width divided by the width of standard a standard silicon PMOS component in a reference standard inverter), and ωn is any relative width change in the NMOS transistor. This expression is an approximation because any large change in device width can affect the constant B, which is associated with the overall inverter capacitance.
A standard Si inverter is typically optimized to minimize stage delay by widening the PMOS transistor in order to balance the current drive in the NMOS and PMOS transistors. This requirement arises because standard silicon devices have a much higher NMOS drive current than PMOS drive current (due to electrons having a much higher mobility than holes in unstrained silicon).
Strained silicon with 20 atomic % Ge on a relaxed SiGe substrate can increase electron mobility by approximately 80%, with a hole mobility at best only slightly enhanced. Thus, strained silicon can cause an increase in mobility mismatch, and, therefore, an increase in drive current mismatch between the NMOS and PMOS transistors in the inverter. Therefore, the inverter stage delay generally does not decrease by a full 80% when strained silicon is employed as a channel layer.
As the germanium concentration in a relaxed SiGe substrate rises to 30% and to 40%, the hole mobility increases, respectively, by approximately 40% and over 100%. Beyond a concentration of 40%, little or no further enhancement of the hole mobility occurs. At 40% Ge in the relaxed SiGe substrate, the ratio of the drive currents in the NMOS and PMOS transistors generally is nearly the same ratio as in a standard device.
Thus, asymmetrical mobilities and transistor sizes remain a problem for inverters and other semiconductor devices.


An image reading apparatus includes a light source for irradiating a document sheet with light, a row of red light receiving elements arranged in a primary scanning direction for detecting a red component of the light reflected on the document sheet, a row of green light receiving elements arranged in the primary scanning direction for detecting a green component of the reflected light, and a row of blue light receiving elements arranged in the primary scanning direction for detecting a blue component of the reflected light. The row of red light receiving elements, the row of green light receiving elements and the row of blue light receiving elements are displaced from each other in a secondary scanning direction which is perpendicular to the primary scanning direction.

1. Field of the Invention
The present invention relates to an image reading apparatus. More particularly, the present invention relates to a contact-type line image scanner for optically reading a document paper sheet in full color. The present invention also relates to an image sensor chip which may be advantageously incorporated in such an image scanner.
2. Description of the Related Art
In general, a full-color line image scanner comprises a light source for irradiating a document paper sheet with white light, apluralityof red light receiving elements for detecting a red light component of the white light reflected on the document sheet, a plurality of green light receiving elements for detecting a green light component of the reflected white light, and a plurality of blue light receiving elements for detecting a blue light component of the reflected white light. Each of the light receiving elements converts the detected amount of light into a corresponding electric signal.
FIG. 20 of the accompanying drawings illustrates a typical arrangement of light receiving elements in a full-color line image scanner. As shown, a plurality of red light receiving elements 80R, a plurality of green light receiving elements 80G, and a plurality of blue light receiving elements 80B are regularly arranged in a common single row. Specifically, groups of light receiving elements are arranged in a common row in such a manner that each group includes a red light receiving element 80R, a green light receiving element 80G and a blue light receiving element 80B. Each group of three different light receiving elements 80R, 80G, 80B, which corresponds to a single pixel or picture element, has a primary scanning direction dimension S2 and a secondary scanning direction dimension S3, whereas each light receiving element has a primary scanning direction dimension S1. Further, each of the light receiving elements 80R, 80G, 80B is covered by a correspondingly colored filter which allows selective passage of a relevant color component of the white light.
Since the three kinds of light receiving elements detect three different color components of the white light at the same time, the image scanner described above is capable of full-color image reading at high speed. However, the prior art image scanner has been found disadvantageous in the following points.
First, since each group of three different light receiving elements 80R, 80G, 80B corresponds to a single picture element, the primary scanning direction dimension S2 needs to be set equal to or less than the primary scanning direction dimension of the single picture element. Therefore, the primary scanning direction dimension S1 of each light receiving element must be set less than 1/3 of the primary scanning direction dimension of the single picture element. As a result, the light receiving area of each light receiving element inevitably becomes small, thus leading to a poor reading quality (i.e., a low electrical output). Such a problem is particularly remarkable when the pitch between the respective light receiving elements 80R, 80G, 80B is set small to increase the reading resolution.
Secondly, since the three different light receiving elements 80R, 80G, 80B in each group (corresponding to a single picture element) deviates positionally in the primary scanning direction, there may be a color deviation when the three light receiving elements in the same group read the same picture element of the document sheet.
In the third place, since the three light receiving elements 80R, 80G, 80B in each group are dedicated to different colors, they need to be separately covered by different filters. Therefore, there is a need for separately attaching as many filters as the light receiving elements, consequently resulting in a cost increase.
The above-described problems may be eliminated by providing three different light sources for emitting red light, green light and blue light toward a document sheet with a time lag. In this case, a single kind of light receiving elements in a single row is caused to successively detect the reflected different color light components.
However, the latter solution is also disadvantageous in that the image reading speed becomes low due to the need for actuating the different light sources with a time lag. Further, since each light receiving element (which is normally provided by a phototransistor) is successively caused to detect different colors, unexpected mixture of two or more colors may occur due to incomplete discharge of a charge of the phototransistor. More specifically, as shown in FIG. 21, a phototransistor constituting each light receiving element retains a certain amount of previous charge (represented as "charge remainder ratio") even after discharging for another light detection, so that two successive detection for two different colors may result in unexpected color mixture.

Image reading apparatus and image sensor chip thererfor


A preferably palm-sized cleat which is generally oval in shape defines a passageway for a line to pass completely through the body of the cleat. The body of the cleat has mutually resilient sides which bias internal structure in the body into a locked mode in which the line is gripped by the internal structure and will not slide through the passage way. When the sides of the body are squeezed together, the line is freed and will move freely in either direction through the passageway.

The invention is in the field of cleats and tensioning devices which have two basic modes of operation, a first mode in which they lock onto a line, and a second, release mode in which the line is freed to move longitudinally through the cleat.
Although there are innumerable applications for such cleats, a typical application and one which clearly exemplifies its use is that of a line tieing a tent down to a tent stake. Typically the line is attached to part of the tent, and loops around a stake. The size of the line loop around the stake is then changed to increase or decrease the tension on the line.
Increasing the loop size of a tent hold-down may be done with a simple knot called a tautline hitch which is used by the boy scouts. There are also other commercially available, simple cleat elements, generally involving a very simple piece of metal or plastic having a wedged slot therein, with the bitter end of the line being connected to the larger end of the slot so that when the line is tensioned, it pulls into the converging, wedged end of the slot tightly over the tensioned length of the line.
These means of tensioning lines are simple and easy to use. they are not, however, universally reliable. Jostling of the tent or moving the line may cause the loop fastening to migrate, loosening the line. There is a need, therefore, for a more sophisticated cleat which has the features of a very positive gripping action when it is in the locked mode, and also being susceptible to a very easy, quick one-handed release.


A process for forming a thermally enhanced Chip On Board semiconductor device (10) with a heat sink (30) is described. In one aspect, a thermally conducting filled gel elastomer material (50) or a silicon elastomeric material or elastomeric material, if the material is to be removed, is applied to the die surface (18) to which the heat sink is to be bonded. During the subsequent glob top application and curing steps, difficult-to-remove glob top material (38) which otherwise may be misapplied to the die surface adheres to the upper surface of the elastomer material. The elastomer material is removed by peeling prior to adhesion bonding of the heat sink to the die. In another aspect, the thermally conducting filled gel elastomer material (70) is applied between a die surface and the inside attachment surface (46) of a cap-style heat sink to eliminate overpressure on the die/substrate interface.

1. Field of the Invention
This invention relates generally to integrated circuit packages and methods of package assembly. More particularly, the present invention pertains to the manufacture of Chip On Board devices with heat sinks for high power dissipation.
2. State of the Art
Semiconductor devices are used in a wide variety of products, including computers, automobiles, integrated circuit cards, audio/video products, and a plethora of other electronic apparatus.
Modern electronic appliances such as computers have hundreds of integrated circuits (IC) and other electronic components, most of which are mounted on printed circuit boards (PCB). Heat is generated by such components. The heat generated by many IC""s and other electronic components with simple circuits may often be dissipated without an additional heat sink. However, components requiring added heat sinks are becoming more numerous as the required speed, circuit complexity, and circuit density have increased.
In particular, as semiconductor devices have become more dense in terms of electrical power consumption per unit volume, heat generation has greatly increased, requiring package construction which dissipates the generated heat much more rapidly. As the state of the art progresses, the ability to adequately dissipate heat is often a severe constraint on the size, speed, and power consumption of an integrated circuit design.
The term xe2x80x9cheat sinkxe2x80x9d is used herein in general reference to a passive heat transfer device, for example, an extruded aluminum plate with or without fins thereon. The plate is thermally coupled to an electronic component, e.g. semiconductor die, to absorb heat from the component and dissipate the heat by convection into the air. In this application, a heat sink will be distinguished from a xe2x80x9cheat spreaderxe2x80x9d, the latter pertaining to a member which channels heat from a semiconductor die to leads which exit the die package. However, a heat sink and a heat spreader may together be used to cool a device.
Integrated circuit devices are constructed by making e.g. a (silicon or germanium) semiconductor die with internal and surface circuits including transistors, resistors, capacitors, etc. A single semiconductor die may contain thousands of such components and generate considerable heat. Electrical connection pads on an xe2x80x9cactivexe2x80x9d surface of the semiconductor die are connected to the various die circuits. The integrated circuit device also includes electrical leads enabling the electrical connection pads of the semiconductor die to be connected to circuits on a printed circuit board (PCB) (or other substrate) of an appliance.
Dissipation of generated thermal energy is necessary for safe operation of an electronic appliance. An excessively high temperature of an IC may cause a circuit board fire and damage or destroy the appliance. High temperatures cause failure of the integrated circuits themselves. State of the art methods for absorbing and dissipating thermal energy from high speed Chip On Board (COB) semiconductor devices are inadequate for any or all of the following reasons: (a) insufficient heat transfer capability, (b) excessively large package size, especially the profile height, (c) complexity of manufacture, and/or (d) excessive cost.
Current methods of forming glob topped Chip On Board devices with heat sinks are shown in U.S. Pat. No. 5,552,635 of Kim et al., U.S. Pat. No. 5,477,082 of Buckley III et al., U.S. Pat. No. 5,468,995 of Higgins III, U.S. Pat. No. 5,610,442 of Schneider et al., and U.S. Pat. No. 5,659,952 of Kovac et al.
In U.S. Pat. No. 5,450,283 of Lin et al., a method for making a semiconductor device with an exposed die backside is described. The method includes providing a printed wiring board (PWB) substrate with conductive traces, on which a semiconductor die is flip mounted and connected to the conductive traces. An electrically non-conductive coupling material is placed between the die and substrate. A package body is formed around the perimeter of the die, covering a portion of the conductive traces and any portion of the coupling material extending beyond the die perimeter. The backside of the die is left exposed through the use of a thin layer of tape placed in the mold cavity prior to the transfer molding of the package body around the die to prevent the flow of molding material forming the package from flowing on the inactive backside of the die. If the thin layer of tape adheres to the die after removal of the semiconductor device from the mold cavity, the thin layer of tape is removed from the die of the semiconductor device.
A device made with multiple layers of encapsulant is shown in U.S. Pat. No. 5,379,186 of Gold et al.
In accordance with the invention, an improved method for fabricating a Chip On Board semiconductor device requiring enhanced heat dissipation is applicable to direct attachment of semiconductor devices, such as dynamic memory semiconductor dice, to substrates, such as circuit boards and the like, and to the formation of modules incorporating a substrate, such as a circuit board.
In one aspect of the invention, an elastomer is used to cover a portion of a semiconductor die prior to glob top application of the die to the circuit board. The elastomer is removed, e.g. by peeling, from the die surface and includes any glob top material which has inadvertently been applied to the elastomer. Thus, the portion of the semiconductor die remains free of contaminants. If desired, since a portion of the semiconductor die is free of contaminants, providing a good adhesion surface, a heat sink may be attached to such portion of the semiconductor die. The method is applicable to both wire-bonded dies and flip-chip die bonding to circuit boards. Alternately, the elastomer may be retained on a portion of the semiconductor die after the molding or glob-topping of the die for the attachment of a heat sink thereto, if desired. The elastomer may be a highly thermally conductive elastomer to enhance the heat transfer from the semiconductor die to the surrounding environment. An example of a highly thermally conductive elastomer is a metal-filled elastomer or an elastomer filled with a highly thermally conductive material like metal.
The preferred elastomer is highly heat conductive, very compliant, has a relatively low adhesiveness and a high surface wetting property, all the type of properties that enhances heat transfer from the semiconductor die.
In another aspect of the invention, a heat conductive cap is formed over a semiconductor die and comprises a heat sink. A layer of the metal filled gel elastomer is placed between the non-active surface of a die and the cap. Compressing the die into the cap forms the desired adhesion to retain the die within the cap. The compliance of the elastomer enables the die and cap to be pressed together without overpressuring the die/circuit board interface. In addition, the high thermal conductivity of the elastomer enables devices having a very high heat output to be cooled to temperatures enabling reliable operation.
The method of the invention includes steps for forming direct die-to-circuit board connections for xe2x80x9cheat sinked diesxe2x80x9d as well as for forming xe2x80x9cheat sinkedxe2x80x9d die modules which may be themselves connected to a substrate such as a circuit board.
These and other features and advantages will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings. It is important to note that the illustrations are not necessarily drawn to scale, and that there may be other embodiments of the invention which are not specifically illustrated. Like elements of the various figures are designated by like numerals.

Chip on board and heat sink attachment methods


A device for measuring the fill level in a container at least partially filled with a liquid, particularly for determining the liquid level in a fuel tank, in which a measuring resistor, comprising a metallic resistance layer having a great temperature coefficient of the specific resistance is carried by a carrier foil. The portion of the resistance layer disposed in the liquid remains cold, while that portion above the liquid is at a higher temperature, whereby the difference between the present resistance and that of an empty tank is proportional to the fill level within the tank. The change of resistance preferably is measured in connection with that of a comparator resistor which is not heated and compensates for temperature influence etc. An influence on the measurement due to convection in the fuel tank is prevented by means of covering sheets which are spaced a small distance from the resistors by means of suitable spacing strips.

The invention relates to a device for measuring the level of liquid in a container, particularly a fuel tank or the like, which contains a temperature-dependent electric resistor which is adapted to be heated by a suitable means and utilizes a measuring device which indicates changes in the resistance value as a result of change in the fill level of the liquid.
A measuring device for reading liquid levels is known from German AS No. 23 08 823, in which is disclosed a plurality of sheath conductors, of which one part includes resistance wires and heat conductors carrying current, and another part contains only resistance wires wound on a carrier bar. Such resistance wires are arranged in a measuring bridge circuit, whereby the temperature-dependent resistance wires of a heated sheath conductor are arranged in one bridge arm and those of an unheated sheath conductor are arranged in another bridge arm of the resistance measuring bridge. This type of measuring device for indicating the level reading, is particularly adapted for use in measuring liquid levels in nuclear reactor power plants where, as a rule, the level of water is to be measured.
Such devices, however are not suitable for the measurement of liquid levels of fuels or other readily volatile compounds. The mass of the measuring body to be heated is very large in relationship to its surface which can be contacted by the liquid. This produces not only a great inertia in the display operation and a low precision of measurement, as a result of the heat dissipation in the measuring body, but in addition a relatively high heat output must be expended because a significant temperature gradient exists within the measuring device, and only the mean temperature difference between the part of the measuring device disposed in the liquid and the part disposed outside of the liquid can be evaluated to provide a measurement. Consequently, the part disposed outside of the liquid is relatively strongly heated and can produce a vaporization of the liquid at the boundary area. This results not only in the loss of liquid due to vaporization, but also where employed in connection with combustible liquids, results in an increased danger of explosion. Moreover, as a result of the necessary heat output and the low heat conductivity of fuels, in such a measuring device, a heating occurs in the part of the resistor lying within the liquid that greatly weakens the signal.
It has also been proposed to employ the change in capacitance between two neighboring electric conductors or conductor surfaces in connection with the determination of the height of a liquid level. Such methods involve a relatively high outlay for apparatus and are susceptible to contamination during operation. Further, the influence of unavoidable supply line capacitances on the measuring result is extremely difficult to suppress.

Device for measuring the level of a liquid in a container


A rubber composition containing. (A) a bismaleimide compound represented by the general formula (I) ##STR1## wherein R is a divalent acyclic aliphatic group, cyclic aliphatic group, aromatic group, or alkylaromatic group, these groups optionally containing a hetero atom selected from O, N and S in their chain or side substituent, PA0 (B) a sulfenamide compound represented by the general formula (II) ##STR2## wherein R.sub.1 and R.sub.2 denote independently from each other a hydrogen atom, an acyclic aliphatic group, or cyclic aliphatic group, or R.sub.1 and R.sub.2 together denote a chain aliphatic group which optionally contains an oxygen atom, provided that R.sub.1 and R.sub.2 cannot simultaneously denote a hydrogen atom, PA0 (C) a dithiophosphoric acid compound represented by the general formula (III) ##STR3## wherein R.sub.3 and R.sub.4 denote each an aliphatic group, and (D) sulfur; or PA0 (A) a bismaleimide compound represented by the general formula (I) defined above, PA0 (E) an aromatic carboxylic acid anhydride, PA0 (F) sulfur and/or a sulfur donor, and PA0 (G) vulcanization accelerators.

1. Field of the Invention
This invention relates to a rubber composition having improved rubber properties. More particularly, it relates to a rubber composition which is excellent in resistance to reversion in the vulcanization step and is excellent in such rubber properties as resistance to thermal degradation and resistance to deterioration due to flex cracking.
2. Description of the Prior Art
In recent years, increasingly higher levels of mechanical properties and heat resistance than before have come to be required for rubber goods such as tires and belts.
It has been known for a long time for improving the mechanical properties of rubber to use a large amount of sulfur as a cross-linking agent to increase the cross-linking density. However, the use of a large amount of sulfur has a serious defect in that it gives rise to a severe reversion in the vulcanization step and a marked decrease in resistance to heat and resistance to flex cracking in vulcanized rubbers, although it improves such mechanical properties of vulcanized rubber as hardness and tensile strength.
To ovbiate such a defect of sulfur cross-linking, there has been also proposed a method of adding a bismaleimide compound to a sulfur vulcanization system containing dibenzothiazyl disulfide (MBTS) or tetramethylthiuram disulfide (TMTD). However, though the use of this method can correct the above-mentioned defect to some extent, the improvement is not yet fully satisfactory. Moreover, the method have difficulties in that since it requires a large amount of costly bismaleimide compounds it leads to a marked increase in cost of rubber compounds and further that when a vulcanization accelerator of sulfenamide type, which is used chiefly for tires and the like in rubber industry, is used in place of MBTS or TMTD the effect of addition of bismaleimide compound is hardly observed, so that vulcanization accelerators which can be used in combination with bismaleimide compounds are limited to those giving a short scorch time such as MBTS and TMTD, and consequently it can be used only in a limited field such as the manufacture of footwears.
Thus, prior art rubber compositions are not simultaneously satisfactory in such properties as scorching stability, resistance to reversion, resistance to thermal degradation, and resistance to deterioration due to flex cracking.
In view of these circumstances, the present inventors have made an extensive study to obtain rubber compositions which, in all the sulfur vulcanization systems including those containing sulfenamide type accelerators, show an excellent resistance to reversion in vulcanization step and exhibit excellent rubber properties including resistance to thermal degradation and resistance to flex cracking. As a result, it has been found that a rubber composition comprising natural rubber and/or synthetic rubber compounded with a bismaleimide compound represented by the general formula (I), a sulfenamide compound represented by the general formula (II), a dithiophosphoric acid compound represented by the general formula (III), which are mentioned later, and sulfur, or a rubber composition comprising natural rubber and/or synthetic rubber compounded with a bismaleimide compound represented by the general formula (I) mentioned later, an aromatic carboxylic acid anhydride, sulfur and/or a sulfur donor and vulcanization accelerators can, for the first time in all the sulfur vulcanization systems including those containing sulfenamide type accelerators, give mechanical properties which are in no way inferior to those obtainable by using a large amount of sulfur and further show markedly improved properties including resistance to reversion, resistance to heat aging, and resistance to flex cracking, the insufficiency of which properties has been the defect of sulfur vulcanization. This invention has been achieved on the basis of above findings.

Rubber composition with nitrogen and phosphorous compound


High-quality, single-crystalline silicon-germanium (Si(1-x)Gex) having a high germanium content is provided. Layers of the high-quality, single-crystalline silicon-germanium can be grown to high sub-critical thicknesses and then released from their growth substrates to provide Si(1-x)Gex films without lattice mismatch-induced misfit dislocations or a mosaic distribution of crystallographic orientations.

Si(1-x)Gex single-crystal thin films have been grown epitaxially on silicon. However, the thickness of these films is limited because, beyond a certain thickness (referred to as the critical thickness), the strain induced in the Si(1-x)Gex by the lattice mismatch between the growth substrate and the Si(1-x)Gex begins to plastically relax, which results in the formation of lattice mismatch-induced misfit dislocations in the Si(1-x)Gex. Moreover, as the Ge content of the Si(1-x)Gex increases, the critical thickness of the film decreases. As a result, high-quality, single-crystalline films of Si(1-x)Gex with a high Ge content cannot be grown on silicon to adequate thicknesses for many practical processing techniques and device applications. High-Ge-content Si(1-x)Gex single-crystal thin films can be grown epitaxially on germanium. However, the critical thickness of these films decreases with increasing silicon content and, therefore, high-quality Si(1-x)Gex films with thicknesses useful for many device applications can only be achieved for Si(1-x)Gex films with a very high Ge content when germanium is used as the growth substrate.
High Ge content Si(1-x)Gex has been grown epitaxially over compositionally graded, plastically relaxed growth substrates. Unfortunately, the plastically relaxed growth substrates are characterized by lattice mismatch-induced misfit dislocations and their associated threading dislocations, and these propagate through the Si(1-x)Gex. Moreover, the resulting Si(1-x)Gex films are characterized by a non-uniform strain distribution and small-angle tilt boundaries, which degrade the crystal quality and, therefore, the performance of devices incorporating the Si(1-x)Gex.

High-quality, single-crystalline silicon-germanium films


An element and a process for recovering silver from a photographic developer solution containing silver ions. The silver recovery element (10) comprises a support (12) having a hydrophilic colloid layer (16) containing physical development nuclei on at least one of two opposing outer surfaces. Raised portions (20) space adjacent surfaces in the element's rolled-up configuration. The element can be contacted with the developer solution to recover silver from the solution.

Photographic developer solutions can contain undesirably high amounts of silver. Silver lost in effluent streams can present an economic cost as well as an environmental discharge concern. A seasoned photographic developer solution containing silver can also contain sulfite, which can react with silver in a photographic element to increase the amount of silver complex in solution. The silver complex tends to undergo reduction and form silver sludge. Silver sludge is a problem because it can decrease the practical useable lifetime of the developer solution. The silver sludge can foul developer apparatus such as rollers and belts and the like, and consequently foul photographic materials in contact with such apparatus, resulting in poor photographic quality. Silver sludge can also interfere with the flow of developer solution, resulting in poor photographic finish. Silver sludge formation on the developer apparatus and on the walls of the development tanks can necessitate more frequent maintenance and cleaning and result in more down time of the apparatus.
Efforts to minimize silver sludge formation have met with limited success. Some prior art methods employ the addition of mercapto or related compounds to the developer solution to inhibit the formation of silver sludge. A problem with this approach is that such additives can inhibit photographic development and decrease sensitivity. Another problem is that mercapto compounds tend to oxidize, which decreases the silver sludge-inhibiting effects.
Another prior art approach is the use of such mercapto compounds as a component in a photographic emulsion layer. This, however, can result in loss of photographic performance, such as speed and sensitivity loss.
Another prior art approach for recovering silver from a photographic developer solution employs a film having a hydrophilic colloid layer which contains a compound, such as a mercapto compound, capable of adsorbing silver. This can also have the above-noted problems concerning mercapto or related silver adsorbing compounds.
Also known is the use of physical development nuclei (sometimes termed active nuclei), such as Carey Lea Silver, as silver precipitating agents. They can be used to cause silver sludge to settle to the bottom of a development tank. This approach, however, does not result in satisfactorily decreasing, or eliminating, the problem of silver sludge formation.
Another prior art approach is to provide a silver precipitating layer in a photographic element having an image-forming silver halide layer. The silver precipitating layer, which can comprise a hydrophilic colloid containing metal sulfides or colloidal metals, e.g. Carey Lea silver, can decrease the migration of silver or silver halide and lessen silver buildup in a photographic developer solution. A problem with this approach is that silver and silver halide captured in the precipitating layer can impede light transmission and result in decreasing the photographic quality of the exposed film and developed image.
Also known is a processing element comprising a hydrophilic element containing a dispersed silver-precipitating agent, for example a physical development nuclei such as Carey Lea silver. The element is used, however, in a diffusion transfer photographic development process and not for silver recovery from an aqueous solution.


A settlement terminal includes a card reader, a settlement processing unit including a processor programmed to carry out a settlement process using information acquired through the card reader and a tampering detection process, a storage device in which a first set of programs is stored after encryption by a first key and a second set of programs is stored after encryption by a second key, each set of programs including a first program for operating the card reader, and a second program for carrying out the settlement process. Upon detection of tampering, the processor of the settlement processing unit notifies an external terminal of the tampering and upon receiving an update instruction from the external terminal, updates a current set of programs used for operating the card reader and carrying out the settlement process from the first set to the second set.

In various settlement terminals, e.g., a card settlement terminal which carries out the settlement of a transaction by a credit card, tampering can occur to change the terminal to output recorded information used for a settlement, such as the credit card information read from a credit card. For this reason, various events serving as signs of changes to the terminal, such as forcibly opening a housing, are monitored, and in a case in which such an event occurs, the terminal is prevented from operating normally thereafter by deleting a program or the data necessary for the normal operation thereof.
However, if the configuration of the tamper detection technology is known, it is possible to avoid detection of tampering relatively easily. Further, in a case in which a treatment such as deleting a program, or the taking of data occurs, if the deleted program or data is not restored, the normal operation of the terminal cannot be restored.

Settlement terminal and method of protecting data stored in the settlement terminal against tampering


A system for performing a medical procedure is provided comprising at least one tool and a tool support for supporting a distal portion of the tool. An operator manipulates a human interface device and produces control signals sent to a controller. The controller manipulates the tool support based on the received control signals.

There are numerous types of steerable multi-linked probes, and such devices are utilized in a variety of different applications. Robert Sturges' U.S. Pat. No. 5,759,151, which is hereby incorporated by reference in its entirety, discloses a flexible, steerable device for conducting exploratory procedures. The device includes at least one spine, each having stiffening means for selectively rendering the spine rigid and flexible along its length. A flexible sheath surrounds the spine and is axially slidably moveable relative to the spine so that the sheath will follow and conform to the shape of a spine in the rigid state and resist further flexure when the spine is in a relaxed state. A steerable distal tip is provided on the distal end of the device. Controls for the distal tip are mounted on the proximal end of the device. Mechanisms are provided on the distal end of the device for selectively activating and deactivating the stiffening means of the spine. An instrument conduit may be mounted on the sheath. Howie Choset's U.S. patent application Ser. No. 11/630,279, which is hereby incorporated by reference in its entirety, discloses a feeder mechanism for advancing and retracting both an inner core and an outer sleeve, as well as selectively applying tension to control cables used for steering and causing either the inner core or outer sleeve to transition between a rigid state and a limp state.
U.S. Pat. No. 6,610,007 to Amir Belson, et. al., incorporated herein by reference in its entirety, discloses a steerable endoscope having an elongated body with a selectively steerable distal portion and an automatically controlled proximal portion. The endoscope body is inserted into a patient and the selectively steerable distal portion is used to select a desired path within the patient's body. When the endoscope body is advanced, an electronic motion controller operates the automatically controlled proximal portion to assume the selected curve of the selectively steerable distal portion. Another desired path is selected with the selectively steerable distal portion and the endoscope body is advanced again. As the endoscope body is further advanced, the selected curves propagate proximally along the endoscope body, and when the endoscope body is withdrawn proximally, the selected curves propagate distally along the endoscope body. This creates a serpentine motion in the endoscope body allowing it to negotiate tortuous curves along a desired path through or around and between organs within the body.
For medical use and other critical applications, it is extremely important that each device not only perform as intended and within known specifications, but have repeatable performance and otherwise consistent operation from use to use. For these and other reasons, there is a need for systems, devices and methods which provide integrated calibration routines and mechanisms.


A shift control device for an automatic transmission is provided with an automatic shift mode and a manual shift mode instructed by a manual operation of a driver. The shift control device includes at least one processor and at least one memory including computer program code that cause the shift control device to measure a following distance between an own vehicle and a front vehicle, measure an accelerator opening of an engine, judge whether the measured following distance is equal to or less than a predetermined set value if a downshift is instructed by a manual operation of the driver and the measured accelerator opening is fully closed, and determine a target shift stage based on the following distance if the following distance is equal to or less than the set value. Accordingly, the shift control device downshifts to the target shift stage.

A conventional shift control device for an automatic transmission for a vehicle includes an automatic shift mode for performing a shift operation by determining a shift stage or a gear ratio to be set on the basis of a running condition and a manual shift mode for performing a shift operation instructed by a manual operation of a driver. Such automatic transmission is configured, for example, to instruct an upshift or a downshift stage by stage by operating a gear shift lever in a manual range, or instruct an upshift or a downshift stage by stage every time a paddle, provided to a steering wheel, is pushed, thereby allowing to instruct a shift operation by a manual operation (see Patent Document 1 below for example).
As described above, in the manual shift mode of the conventional automatic transmission, the downshift operation can be performed by instructing a downshift by one shift stage per operation. Due to this, when a multistage downshift is desired, the downshift operation needs to be performed multiple times, taking much time for performing the multistage downshift. Since a downshift by the manual operation requires approximately 500 milliseconds to one second per operation, it takes approximately at least two seconds if a downshift, for example, by four shift stages is desired.
Automatic transmissions in recent years are significantly multistaged with small gear ratios, an engine braking may be insufficiently effective by downshifting only by one stage per operation. Due to this, at the time of applying an engine brake by a manually-operated downshift operation, multiple downshifts are required before resulting in an intended amount of engine brake and accordingly likely to need much time. Therefore, for example, when a user is about to apply an engine brake in response to a following distance closer to a front vehicle, the driver might carelessly approach the front vehicle, failing to keep a proper following distance. Thus, the manually-operated engine brake has been less user-friendly.
As a prior art for keeping the following distance to the front vehicle, for example, Patent Document 2 discloses vehicle speed control using a radar installation for acquiring information such as a relative position and a relative distance to the front vehicle so that based on such information, the driver can follow the front vehicle, keeping the following distance constant.
In addition, Patent Document 3, for example, discloses collision reducing brake control for evading or reducing collision by automatically apply a brake when an external sensor such as a camera or a radar installation detects an object in front of a vehicle.

Shift control device for automatic transmission