The present invention relates to a recombinant antibody composition which is a human IgG1 antibody, comprises a CH2 domain in which amino acids at positions 276 and 339 indicated by the EU index as in Kabat, et al. are replaced by other amino acids and has more improved complement-dependent cytotoxic activity than an antibody comprising a CH2 domain before the amino acids are replaced; a DNA encoding the antibody molecule or a heavy chain constant region of the antibody molecule contained in the recombinant antibody composition; a transformant obtainable by introducing the DNA into a host cell; a process for producing the recombinant antibody composition using the transformant; and a medicament comprising the recombinant antibody composition as an active ingredient.

1. Field of the Invention
The present invention relates to a recombinant antibody composition which is a human IgG1 antibody, comprises a CH2 domain in which amino acids at positions 276 and 339 indicated by the EU index as in Kabat, et al. are replaced by other amino acids and has more improved complement-dependent cytotoxic activity than an antibody comprising a CH2 domain before the amino acids are replaced; a DNA encoding the antibody molecule or a heavy chain constant region of the antibody molecule contained in the recombinant antibody composition; a transformant obtainable by introducing the DNA into a host cell; a process for producing the recombinant antibody composition using the transformant; and a medicament comprising the recombinant antibody composition as an active ingredient.
2. Brief Description of the Background Art
Since antibodies are protein molecules having high binding activity and binding specificity to a target molecule (antigen) and high stability in blood, applications thereof to diagnostic, preventive and therapeutic agents for various human diseases have been attempted (Non-patent Document 1). Although antibodies are generally produced by administering (immunizing) an antigen to a non-human animals antibodies obtained from a non-human animal have an amino acid sequence specific to the species and side effects are caused due to that the antibodies are recognized as foreign substances in the human body. Accordingly, human chimeric antibodies or humanized antibodies have been prepared from antibodies of animals other than human (nonhuman animals) using gene recombination techniques (Non-patent Documents 2 to 5).
The human chimeric antibodies and humanized antibodies have resolved problems possessed by non-human animal antibodies such as mouse antibodies, such as the high immunogenicity, low effector function and short blood half-life, and applications of monoclonal antibodies to pharmaceutical preparations were made possible by using them (Non-patent Documents 6 to 9). In the Unites States, for example, a plurality of humanized antibodies have already been approved as an antibody for cancer treatment, and are on the market (Non-patent Document 10).
These human chimeric antibodies and humanized antibodies actually show effects to a certain degree at clinical level, but therapeutic antibodies having higher effects are in demand. For example, in the case of single administration of RITUXAN™ (Non-patent Document 11) (manufactured by IDEC/Roche/Genentech) which is a human chimeric antibody to CD20, it has been reported that its response ratio for recurrent low malignancy non-Hodgkin lymphoma patients in the phase III clinical test is no more than 48% (complete remission 6%, partial remission 42%), and its average duration of response is 12 months (Non-patent Document 12). In the case of combination use of RITUXAN™ and chemotherapy (CHOP: Cyclophosphamide, Doxorubicin, Vincristine), it has been reported that its response ratio for recurrent low malignancy and follicular non-Hodgkin lymphoma patients by the phase II clinical test is 95% (complete remission 55%, partial remission 45%), but side effects due to CHOP were found (Non-patent Document 13). In the case of single administration of HERCEPTIN™ (manufactured by Genentech) which is a humanized antibody to HER2, it has been reported that its response ratio for metastatic breast cancer patients in the phase III clinical test is only 15%, and its average duration of response is 9.1 months (Non-patent Document 14).
The human antibody molecule is also called immunoglobulin (hereinafter referred to as Ig) and classified into isotypes of IgA1, IgA2, IgD, IgE, IgG1, IgG2, IgG3, IgG4 and IgM based on its molecular structures IgG1, IgG2, IgG3 and IgG4 having relatively high homology in amino acid sequences are genetically called IgG. Human IgG is mainly used as a therapeutic antibody.
An antibody molecule comprises two kinds of polypeptides, i.e. a heavy chain (hereinafter referred to as H chain) and a light chain (hereinafter referred to as L chain). A human IgG antibody molecule comprises two H chains and two L chains. Also, an H chain comprises an H chain variable region (hereinafter referred to as VH) and an H chain constant region (hereinafter referred to as CH), and an L chain comprises an L chain variable region (hereinafter referred to as VL) and an L chain constant region (hereinafter referred to as CL). The H chain constant region comprises four domains which are respectively called CH1, hinge, CH2 and CH3 domains from the domain close to VH located at the heavy chain N-terminal in this order. Also, the CH2 domain and CH3 domain in combination are called Fc.
An antibody binds to an antigen via an antigen-biding region (hereinafter referred to as Fv) comprising VH and VL and binds to an effector molecule in the immune system such as a receptor or a complement via the H chain constant region. Under the mediation of the binding to the effector molecule in the immune system, the antibody induces an effector activity such as a complement-dependent cell-mediated cytotoxic activity (hereinafter referred to as CDC activity), an antibody-dependent cellular cytotoxic activity (hereinafter referred to as ADCC activity) or a phagocytic activity so as to eliminate the antigen or cells (a pathogen or tumor cells) expressing the antigen.
To induce the ADCC activity or phagocytic activity, it is important that the antibody binds to a member of the Fc gamma receptor (hereinafter referred to as FcγR) family expressed on the surface of various leukocytes such as natural killer cells (hereinafter referred to as NK cells), monocytes, macrophages or granulocytes. The FcγR family includes activated FcγR and regulated FcγR. FcγRI, FcγRIIa, FcγRIIIa and FcγRIIIb belong to the activated FcγR, and FcγRIIb belongs to the regulated FcγR. A human IgG antibody strongly binds to such a receptor and consequently induces the ADCC activity or phagocytic activity of leukocytes.
The ADCC activity is a reaction in which leukocytes such as NK cells mainly lyse targets cell under the mediation of an antibody. The antibody binds to an antigen on the surface of the target cells via Fv and binds to FcγRIIIa on the surface of NK cells via Fc. As a result, the NK cells release cytotoxic molecules such as perforin or granzyme and thus lyse the target cells (Non-patent Documents 15 and 16).
The CDC activity is a reaction in which a group of serum proteins called complements lyses target cells under the mediation of an antibody. The complements are classified into C1 to C9 proteins, and they are subjected to chain reaction to thereby induce the CDC activity. Each of the complement proteins is activated by reacting with a specific complement protein and then reacts with the subsequent complement protein. These chain reactions start with the binding of the first complement component C1 to the Fc of an antibody, which has been bonded via Fv to an antigen on the surface of target cells, via C1q that is one of the proteins constituting C1. Finally, complexes of C5 to C9 are polymerized together to form a hole in the cell membrane of the target cells, which results in the lysis of the target cells (on-patent Documents 15 and 16).
Four human IgG isotypes (IgG1, IgG2, IgG3 and IgG4) are highly homologous with each other in the amino acid sequence in the H chain constant region except for the hinges showing a wide variety. However, these isotypes induce an effector activity of different strengths (Non-patent Document 17). In general, the ADCC activity decreases in the following order: IgG1>IgG3>IgG4≧IgG2 (Non-patent Documents 18 and 19), while the CDC activity decreases in the following order: IgG3≧IgG1>>IgG2≈IgG4. As discussed above, the binding of an antibody to C1q is important in inducing the CDC activity. The biding constants (Ka) in the binding of C1q to a monomeric antibody molecule in human IgG isotypes, i.e., IgG1, IgG2, IgG3 and IgG4 are 1.2×104, 0.64×104, 2.9×104 and 0.44×104, respectively (Non-patent Document 20), reflecting the difference in CDC activity among these isotypes.
Concerning the drug effect mechanisms of clinically employed antibody drugs, the importance of ADCC and CDC activities has particularly attracted public attention. It is reported that RITUXAN™ as described above, which is a human chimeric antibody of the IgG1 isotype, shows ADCC and CDC activities in vitro (Non-patent Document 21). Relating to the clinical effects of RITUXAN™, it is reported that RITUXAN™ shows high therapeutic effects on a patient showing a genotype with high ADCC activity (Non-patent Document 22), that complement components in blood are quickly consumed following the administration thereof (Non-patent Document 23), that the expression of CD59, which is a CDC activity regulator, shows an increase in cancer cells of a patient suffering from recurrence after the administration thereof (Non-patent Document 24), and the like. These reports indicate that RITUXAN™ actually exerts the effector function in the body of a patient. It is also reported that HERCEPTIN™ as described above, which is a humanized antibody of the IgG1 subclass, shows the ADCC activity in vitro (Non-patent Document 25).
Although human IgG1 and human IgG3 are isotypes having excellent ADCC and CDC activities, it is known that human IgG3 antibody has a shorter half life in the blood than other human IgG isotypes and thus quickly disappears from the blood after the administration (Non-patent Document 26). It is also known that human IgG3 has no protein A-binding activity, differing from other human IgG isotypes (Non-patent Document 27). In producing an antibody on an industrial scale, a purification process using protein A is predominant and other processes using, for example, protein G have some problems such as a high purification cost.
It is known that protein A binds to a human IgG antibody molecule (Non-patent Document 28). When indicated by the EU index as in Kabat, et al. (Non-patent Document 29), it is pointed out as the results of X-ray crystallographic analysis that a loop comprising the amino acids at positions 252 to 254, a loop consisting of the amino acids at positions 308 to 312, and a loop comprising the amino acids at positions 433 to 436 are important (Non-patent Document 28). As the results of nuclear magnetic resonance (NMR) analysis, it is further indicated that Ile253, Ser254, His310, Gln311, His433, His435 and His436 are particularly important in the Fc of IgG1 (Non-patent Document 30). Furthermore, Kim, et al. found that the protein A-binding activity was attenuated by replacing His435 of a human IgG1 with Arg435 derived from IgG3 (Non-patent Document 31). Hereinafter, the positions of the amino acids in the amino acid sequence of an antibody molecule are represented based on the EU index as in Kabat, et al. (Non-patent Document 29).
Based on the above it can be said that human IgG1 antibody is the most suitable isotype as an antibody drug, since it has higher ADCC and CDC activities than other isotypes, can be purified using protein A, shows a long half life in blood and has a merit from the viewpoint of production cost. Although a human IgG1 antibody has been employed as drugs in practice as described above, the drug effects exhibited by the existing antibody drugs are still insufficient. Thus, there has been required an antibody drug having improved effects. In order to satisfy this requirement, studies have been made on an antibody having enhanced effector activities. As discussed above, an effector activity of an antibody reflects the binding activity of the H chain constant region to an effector molecule in the immune system. Accordingly, the effector activity of the antibody can be enhanced by enhancing the binding activity of the H chain constant region to the effector molecule in the immune system.
In order to analyze the effector activities of human antibodies, studies have been made on antibodies comprising two kinds of human isotype amino acid sequences which are prepared by partly swapping the amino acid sequences in the heavy chain constant region between two kinds of human isotype antibodies having different effector activity (Patent Document 1 and Non-patent Documents 32 and 33). In late 1980's, Morrison, et al. indicated that antibody molecules, which were prepared by swapping the individual domains (CH1, CH2, CH3 and hinge) in the heavy chain constant region between IgG1 having a high effector activity and IgG4 having a low effector activity, or between IgG2 having a low effector activity and IgG3 having a high effector activity, could be expressed as recombinant proteins (Patent Document 1). As the results of the subsequent analysis on these antibody molecules, they have clarified that the C-terminal side of the CH2 domain is important in the CDC activity of IgG1 and the CH2 domain is important in the CDC activity of IgG3 (Non-patent Document 32); the CH2 domain and hinge are important in the binding of IgG1 and IgG3 to FcγRI (Non-patent Document 33); and the like.
As described above, the CH2 domain is important in the CDC activity. The amino acid sequences of human IgG1 antibody and human IgG3 antibody having high CDC activity have been analyzed. Concerning the amino acid sequences of CH2, it is known that Leu235 (Non-patent Document 34), Asp270, Lys322, Pro329 and Pro331 (Non-patent Document 35) are important in the CDC activity of human IgG1; and Gly233, Leu234, Leu235, Gly236 (Non-patent Document 36) and Lys322 (Non-patent Document 37) are important in the CDC activity of human IgG3. Brekke, et al. analyzed various antibody molecules prepared by transplanting amino acid residues being common to the CH2 domain amino acid sequences of human IgG1 antibody and human IgG3 antibody having high CDC activity or several amino acid residues being different from a human IgG4 antibody having very low CDC activity into a human IgG4 antibody. As a result, they found that the CDC activity of human IgG4 antibody was enhanced by swapping Ser331 in human IgG4 by Pro331 which is common to a human IgG1 and a human IgG3 (Non-patent Document 38).
Moreover, attempts have been made to enhance the CDC activity by swapping a part of the amino acid sequence of the heavy chain constant region of human IgG3 antibody, which is the human IgG isotype having the highest CDC activity, by an amino acid sequence originating in another human IgG isotype. Concerning the hinge lengths of each IgG isotypes, IgG1 has 15 amino acid residues, IgG2 has 12 amino acid residues, IgG3 has 62 amino acid residues and IgG4 has 12 amino acid residues. Thus, the human IgG has a structural characteristic of having a longer hinge than other IgG3 isotypes Non-patent Document 1). The hinge of human IgG3 antibody consisting of 62 amino acids is encoded by four exons on a gene. Michaelsen, et al. reported that the CDC activity of human IgG3 antibody having a hinge that was shortened to 15 amino acid residues by deleting three exons in the N-terminal side among these four exons was higher than IgG3 and IgG1 (Non-patent Document 39). Norderhang, et al. reported that the CDC activity is further increased by swapping the amino acid sequences of the hinge shortened in the above and the amino acid sequences of the hinge of IgG4. Further, Brekke, et al. reported that when the hinge of human IgG3 antibody was swapped by the hinge of human IgG1 antibody, the CDC activity of the resultant antibody was higher than IgG3 and similar to IgG1 or more (Non-patent Document 41).
On the other hand, studies have been made on an antibody prepared by replacing the amino acid sequence of the heavy chain constant region of human IgG1 antibody by an artificial amino acid sequence which is not present in the nature to thereby increase the C1q-binding activity and thus enhance the CDC activity (Non-patent Document 42 and Patent Documents 2 to 5). As described above, the CDC activity is induced by the binding of C1q, which is one of the proteins constituting complement protein C1, to the Fc of an antibody molecule. Idusogie, et al. reported that by replacing Lys326 or Glu333 in the CH2 domain of RITUXAN™ (a human IgG1 chimeric antibody) as described above with an other amino acid, the CDC activity was enhanced twice at most (Non-patent Document 42, Patent Document 2). Furthermore, Idusogie, et al. indicated that by replacing Lys326 or Glu333 in IgG2 with an other amino acid, the CDC activity of IgG2, which inherently corresponds to a several hundredth part of the CDC activity of IgG1, was increased to about one over twenty-five of IgG1 (Patent Documents 3 to 5).
However, such an antibody prepared through the replacement of an amino acid sequence which is not present in the nature has a risk that it is recognized as a foreign matter in the human body and thus induces a side effect similar to the non-human animal antibody as discussed above. On the other hand, the amino acid sequence of an antibody prepared by swapping amino acid sequences between human isotypes is a combination of amino acid sequences of antibodies inherently carried by humans.
In the therapeutic effects of a therapeutic antibody, the ADCC and phagocytic activities induced by the biding of the Fe region of the antibody to FcγR and the CDC activity mediated by the biding of the antibody to C1q are both important. However, the bindings of the antibody to C1q and to the FcγR are both mediated by the Fc and, therefore, it is feared that an amino acid modification aiming to enhance the CDC activity might damage the ADCC activity. In practice, Idusogie, et al. reported that an antibody in which the CDC activity was enhanced by replacing the Fe of human IgG1 antibody with an artificial amino acid sequence showed a serious lowering in the ADCC activity (Non-patent Document 42).
As a procedure for enhancing an effector activity of an antibody other than the replacement in an amino acid sequence, regulation of a sugar chain attached to the constant region of the antibody may be cited. It is known that the ADCC activity of human IgG antibody changes based on the structure of a complex-type N-glycoside-linked sugar chain attached asparagine at position 297 in the Fc (FIG. 1 shows a model view thereof) (Patent Document 6). It is also reported that the ADCC activity of the antibody changes depending on the amounts of galactose and N-acetylglucosamine contained in this sugar chain (Non-patent Documents 43 to 46). However, the ADCC activity is mostly affected by fucose binding to N-acetylglucosamine in the reducing terminal through α1,6-bond in the sugar chain. Namely, an IgG antibody having complex-type N-glycoside-linked sugar chains in which fucose is not bound to N-acetylglucosamine in the reducing terminal in the sugar chains shows remarkably higher ADCC and FcγRIIIa-binding activities than an IgG antibody having complex-type N-glycoside-linked sugar chain in which fucose is bound to N-acetylglucosamine in the reducing terminal in the sugar chains (Non-patent Documents 47, 48 and 49 and Patent Document 7). Although antibody molecules having no fucose in sugar chains exist in vivo as a natural-type, α1,6-fucosyltransferase gene-knockout cells have been known as cells capable of specifically producing an antibody composition having complex-type N-glycoside-linked sugar chains in which fucose is not bound to N-acetylglucosamine in the reducing terminal in the sugar chains (Patent Documents 7 and 8)    Non-patent Document 1: Monoclonal Antibodies: Principles and Applications, Wiley-Liss, Inc. (1995)    Non-patent Document 2: Nature, 312, 643 (1984)    Non-patent Document 3: Proc. Natl. Acad. Sci. USA, 81, 6851 (1984)    Non-patent Document 4: Nature, 321, 522 (1986)    Non-patent Document 5: Nature, 332, 323 (1988)    Non-patent Document 6: Immunol. Today, 21, 364 (2000)    Non-patent Document 7: Immunol. Today, 21, 403 (2000)    Non-patent Document 8: Ann. Allergy Asthma Immunol., 81, 105 (1998)    Non-patent Document 9: Nature Biotechnol., 16, 1015 (1998)    Non-patent Document 10: Nature Reviews Cancer, 1, 119 (2001)    Non-patent Document 11: Curr. Opin. Oncol., 10, 548 (1998)    Non-patent Document 12: J. Clin. Oncol., 16, 2825 (1998)    Non-patent Document 13: J. Clin. Oncol., 17, 268 (1999)    Non-patent Document 14: J. Clin. Oncol., 17, 2639 (1999)    Non-patent Document 15: Chemical Immunology, 65, 88 (1997)    Non-patent Document 16: Immunol. Today, 20, 576 (1999)    Non-patent Document 17: Monoclonal Antibodies: Principles and Applications, Wiley-Liss, Inc. (1995)    Non-patent Document 18: Nature, 332, 323 (1988)    Non-patent Document 19: Journal of Experimental Medicine, 166, 1351 (1987)    Non-patent Document 20: Biochemistry, 15, 5175 (1976)    Non-patent Document 21: Oncogene, 22, 7359 (2003)    Non-patent Document 22: Blood, 29, 754 (2002)    Non-patent Document 23: J. Immunol., 172, 3280 (2004)    Non-patent Document 24: J. Clin. Oncol, 21, 1466 (2003)    Non-patent Document 25: Cancer Immunol Immunother., 37, 255 (1993)    Non-patent Document 26: Cancer Res., 58, 3905 (1998)    Non-patent Document 27: Scand. J. Immunol., 15, 275 (1982)    Non-patent Document 28: Biochemistry, 20, 2361 (1981)    Non-patent Document 29: Sequence of Proteins of Immunological Interest, Fifth Edition (1991)    Non-patent Document 30: FEBS Lett., 328, 49 (1993)    Non-patent Document 31: Eur. J. Immunol., 29, 2819 (1999)    Non-patent Document 32: Journal of Experimental Medicine, 173, 1025 (1991)    Non-patent Document 33: Journal of Experimental Medicine, 173, 1483 (1991)    Non-patent Document 34: Immunology, 86, 319 (1995)    Non-patent Document 35: J. Immunol., 164, 4178 (2000)    Non-patent Document 36: Mol. Immunol., 34, 1019 (1997)    Non-patent Document 37: Mol. Immunol., 37, 995 (2000)    Non-patent Document 38: Ear. J. Immunol., 24, 2542 (1994)    Non-patent Document 39: Scand. J. Immunol., 32, 517 (1990)    Non-patent Document 40: Eur. J. Immunol., 21, 2379 (1991)    Non-patent Document 41: Mol. Immunol., 30, 1419 (1993)    Non-patent Document 42: J. Immunol., 166, 2571 (2001)    Non-patent Document 43: Human Antib Hybrid, 5, 143 (1994)    Non-patent Document 44: Hum Antib Hybrid, 6, 82 (1995)    Non-patent Document 45: Nat. Biotechnol, 17, 176 (1999)    Non-patent Document 46: Biotechnol Bioeng., 74, 288 (2001)    Non-patent Document 47: Clin. Cancer. Res., 10, 6248 (2004)    Non-patent Document 48: J. Biol. Chem., 277, 26733 (2002)    Non-patent Document 49: J. Biol. Chem., 278, 3466 (2003)    Patent Document 1: US2003/0158389A1    Patent Document 2: WO00/42072    Patent Document 3: US2004/0132101 A1    Patent Document 4: US2005/0054832 A1    Patent Document 5: WO00/61739    Patent Document 6: WO02/31140    Patent Document 7: WO03/85107

Effector function enhanced recombinant antibody composition


An automatically retractable seat cover for use by skiers and sports fans who use cold and/or wet seats is described. A plurality of foam pads are enclosed in a flexible cover and are freely interconnected by at least one elastic cord passing through opposed faces thereof which hold the pads in juxtaposition in a closed position at the user's waist and which can be extended by pulling the lowermost pad downwardly so that the pads form a lay flat seat upon which the user can sit, with his own weight holding the seat and cords in the extended position. Upon standing the cords automatically retract the seat to the folded position.

A common cause of discomfort to skiers who use a chair lift or sports fans who sit for relatively long periods in an ice rink or other stadium, is the coldness and hardness of the seats.
Carrying a cushion or even a drying cloth is generally not practical due to the bulk thereof and/or lack of a pocket in which to stow the cushion or cloth when not in use. U.S. Pat. No. 4,689,829 discloses a seat covering device which is simply a cloth flap which can be supported, at one end, around the waist of a skier and let down over the skier's rear when sitting on a ski chair lift. After use the flap is rolled up and secured by a pair of loops adjacent the waist strap. Such a device is easy to let down and use but is difficult or awkward to return to the rolled up position.
Canadian Patent No. 1,235,551 also teaches a skier's seat covering device comprising a plurality of pad members having a flexible connection therebetween with a pair of straps at one end thereof to tie the device around the user's waist and a pair of straps at the other end thereof to tie around the legs when in the extended position and around the waist when in the retracted position. Here again, gravity will allow easy extension but retraction is tedious, awkward and time consuming.
There is, therefore, a need for a seat covering device which can be worn around a user's waist, easily extended and which retracts quickly and easily to the stored position, preferably automatically, and which does not detract from the user's, and particularly a skier's, appearance.


The purpose of the present invention is to provide an automatic analysis device that combines a biochemical analysis unit and a blood coagulation analysis unit and has a high processing capacity while reducing device cost and life-cycle cost. An automatic analysis device is characterized in that when a synthetic-substrate item or latex-agglutination item from among synthetic-substrate, latex-agglutination, and clotting-time blood-coagulation-test items is made to be a first test item and the clotting-time item is made to be a second test item, if there is a measurement request for the first test item and second test item in the same specimen rack, a control unit determines the conveyance path of the specimen rack such that the first test item is measured using a biochemical analysis unit and the second test item is measured using a coagulation time analysis unit and controls a conveyance line.

As an analysis device which analyzes a component amount contained in a sample, an automatic analysis device is known which measures the intensity of transmitted light or scattered light having a single or multiple wavelengths obtained by emitting light from a light source to a reaction solution in which the sample and a reagent are mixed with each other, and which calculates the component amount, based on a relationship between light intensity and density.
According to an automatic analysis device disclosed in PTL 1, optically transparent reaction cells are circumferentially arrayed on a reaction disk which repeatedly rotates and stops. While the reaction disk rotates, a time-dependent change (reaction process data) of the light intensity which is caused by a reaction is measured at regular time intervals, for approximately 10 minutes, by a transmitted light measurement unit arranged in advance. After the reaction is completed, a reaction vessel is cleaned by a cleaning mechanism, and is reused for another analysis.
In a case of the reaction of the reaction solution, two analysis fields such as colorimetric analysis using a color reaction of a substrate and an enzyme and homogeneous immunological analysis using an agglutination reaction caused by binding of an antigen and an antibody are present in a broad sense. In the latter homogeneous immunological analysis, a measurement method is known such as immune-nephelometry and a latex agglutination method.
According to the immune-nephelometry, a reagent containing the antibody is used, an immune complex with a measurement object (antigen) contained in a sample is generated, and both of these are optically detected so as to quantify a component amount thereof. According to the latex agglutination method, a reagent containing latex particles in which the antibody is sensitized on (bound with) the surface is used, latex particles are coagulated through an antigen-antibody reaction with the antigen contained in a sample, and both of these are optically detected so as to quantify a component amount thereof.
In addition, an automatic analysis device disclosed in PTL 2 is also present which measures the coagulation ability of the blood. The blood flows in the blood vessel while holding liquidity. However, if the blood flows out once from a body, coagulation factors present in plasma and platelets are serially activated, and fibrinogen in the plasma is converted into fibrin and precipitated, thereby leading to hemostasis.
This coagulation ability of the blood includes exogenous ability by which the blood leaking out from the blood vessel coagulates and endogenous ability by which the blood in the blood vessel coagulates. Measurement items relating to the coagulation ability of the blood (blood clotting-time) include prothrombin time (PT) of an extrinsic blood coagulation reaction test, activated partial thromboplastin time (APTT) of an intrinsic blood coagulation reaction test, and a fibrinogen amount (Fbg).
Any of these items is configured so that fibrin precipitated by adding a reagent for initiating a coagulation reaction is detected by using optical, physical, and electrical methods. As a method of using optical means, a method is known in which a clotting-time is calculated by emitting light to a reaction solution and detecting a time-dependent intensity change in scattered light or transmitted light from the fibrin precipitated in the reaction solution. According to a representative automatic analysis device of blood coagulation in PTL 2, a blood clotting-time item requires photometric data at intervals of 0.1 seconds. Thus, the reaction is performed in a separate photometric port. If the reaction solution coagulates, a reaction vessel cannot be reused by cleaning. Thus, the reaction vessel has to be discarded. In addition to blood clotting-time measurement, a blood coagulation/fibrinolysis test field also includes coagulation factor measurement and coagulation/fibrinolysis marker measurement. Although the coagulation factor is mainly analyzed by the blood clotting-time measurement, a coagulation/fibrinolysis marker is analyzed by a synthetic substrate method using a chromogenic synthetic substrate or by the previously described latex agglutination method. The blood clotting-time item substantially and stereotypically includes PT, APTT, and Fbg in the related art. In contrast, in addition to D-dimer or fibrin/fibrinogen degradation products (FDP), a coagulation/fibrinolysis marker item includes a soluble fibrin monomer complex (SFMC) and a plasmin-α2 plasmin inhibitor (PIC). The coagulation/fibrinolysis marker item is expected to increase in the future, since there is a demand for early diagnosis/treatment of disseminated intravascular coagulation (DIC). Accordingly, it is desirable to improve a throughput of the automatic analysis device. The blood clotting-time measurement is usually completed within approximately 3 minutes. Therefore, it is possible to maintain the improved throughput by discarding/supplying a reaction vessel after the measurement is completed. On the other hand, according to the synthetic substrate method or the latex agglutination method, the reaction usually continues for 10 minutes. In most cases, the measurement time is longer than that for an item of the clotting-time method. However, according to the automatic analysis device of the blood coagulation in PTL 2, not only the clotting-time but also the coagulation/fibrinolysis marker is analyzed by using a fixed photometric port. Consequently, if there is a measurement request for a synthetic substrate item or a latex agglutination item, there is a problem in that the throughput of the device is extremely decreased. It is conceivable to employ a method of increasing the number of measurement ports in order to suppress the decrease in the throughput of the blood coagulation analysis device. However, the device cost inevitably increases, since the number of light sources, light receiving elements, and amplifier circuits which are required for detection also increases.


In one embodiment, a system includes a turbine combustor having a combustor liner disposed about a combustion chamber, a head end upstream of the combustion chamber relative to a downstream direction of a flow of combustion gases through the combustion chamber, a flow sleeve disposed at an offset about the combustor liner to define a passage, and a barrier within the passage. The head end is configured to direct an oxidant flow and a first fuel flow toward the combustion chamber. The passage is configured to direct a gas flow toward the head end and to direct a portion of the oxidant flow toward a turbine end of the turbine combustor. The gas flow includes a substantially inert gas. The barrier is configured to block the portion of the oxidant flow toward the turbine end and to block the gas flow toward the head end within the passage.

The subject matter disclosed herein relates to gas turbines, and more specifically, to gas turbines with exhaust gas recirculation.
Gas turbine engines are used in a wide variety of applications, such as power generation, aircraft, and various machinery. Gas turbine engines generally combust a fuel with an oxidant (e.g., air) in a combustor section to generate hot combustion gases, which then drive one or more turbine stages of a turbine section. In turn, the turbine section drives one or more compressor stages of a compressor section, thereby compressing oxidant for intake into the combustor section along with the fuel. Again, the fuel and oxidant mix in the combustor section, and then combust to produce the hot combustion gases. Unfortunately, certain components of the combustor section are exposed to high temperatures, which may reduce the life of the components. Furthermore, cooling the components or combustion gases with oxidant may increase the concentrations of oxidant in the exhaust gas.

System and method for barrier in passage of combustor of gas turbine engine with exhaust gas recirculation


A cutting member is manufactured by forming a mixture of cemented carbide and a bearer, and heating the mixture. Then, the heated mixture is injected into a mold for forming a body having a cutting edge in a front surface thereof, a flushing channel extending therethrough, and a rearwardly open blind hold formed centrally in a rear surface thereof. The body is then removed from the mold.

The present invention relates to a tool for rotary, cutting machining, including a tool body, a cutting portion and means for fastening. The tool body has a front surface and the cutting portion has a support surface provided to dismountably abut against each other, substantially in a radial plane. The invention also relates to a separate tool tip, a cutting portion, a tool body as well as to a method for manufacturing a tool tip or a cutting portion.
It is previously known to use interchangeable cutting edges on different types of tools for cutting machining. This technique has however its practical limitation because of strength reasons when it comes to milling- and drilling tools rotating around its longitudinal axis.
Through U.S. Pat. No. 4,684,298 is previously known a drill with a dismountable cutting portion secured in a drill body by two screws, which are provided opposite sides of a central line of the drill. In the known drill, screws transfer torsion which is created during drilling, to the drill body. Such a drill suffers from a number of drawbacks, partly that it becomes statically unstable, which is solved by positioning resilient sleeves around the screws, and partly that the cutting portion is forced to contain less amount of cemented carbide (since the screws need space) whereby the propensity for crack formation increases. In addition the screws are submitted to shear forces and exchange of the cutting portion becomes troublesome.
Furthermore, it is previously known through European Document No. 0 358 901 to provide a drill with a dismountable cutting portion secured in a drill body by means of at least one screw, which is eccentrically positioned relative to the rotational axis of the drill. The cutting portion carries two indexable cutting inserts, and a pilot drill extends centrally therethrough. This known drill has the same drawbacks as mentioned above.


Embodiments of the present invention disclose a display panel and a display apparatus so as to increase the optical conversion efficiency of the display panel. The display panel comprises: an array substrate and a color filter substrate which are arranged oppositely; a liquid crystal layer arranged between the array substrate and the color filter substrate; an upper polarizing layer provided between the color filter substrate and the liquid crystal layer; and a quantum dot excitation layer provided on the color substrate, wherein the upper polarizing layer is configured such that a first linearly polarized light transmitted through the upper polarizing layer irradiates on the quantum dot excitation layer. By disposing the upper polarizing layer between the color filter substrate and the liquid crystal layer, a first linearly polarized light transmitted through the upper polarizing layer arrives at the quantum dot excitation layer, then the quantum dot excitation layer is excited by the first linearly polarized light and emits scattered light, the optical conversion efficiency of the display panel is thus increased.

Field of the Invention
Embodiments of the present invention relate to a display technical field, and in particular, to a display panel and a display apparatus.
Description of the Related Art
Quantum Dot (QD), also referred to as Nanocrystalline, is a kind of nano-particle consisting of group II-VI or III-V elements. A quantum dot generally has a particle size in a range of 1 nm to 20 nm. Since electrons and holes (cavities) in the quantum dot are quantum confined and a continuous energy band structure becomes a discrete energy level structure with molecule characteristic, the quantum dot can emit fluorescence after being excited. The emission spectrum of the QDs can be controlled by changing the size of the QDs, and the emission spectrum of the QDs can cover the whole visible light region by changing the size and the chemical composition of the QDs. Taking CdTe (Cadmium Telluride) QDs as an example, when the particle size is increased from 2.5 nm to 4.0 nm, their emission wavelength can red shift from 510 nm to 660 nm. Here, the red shift refers to a phenomenon that electromagnetic radiation from an object is increased in wavelength for certain reasons. In the visible spectrum, it shows that spectral lines are shifted to the red end of the spectrum by a certain distance, that is, the wavelength becomes longer and the frequency decreases.
The quantum dot has a high optical conversion efficiency which can significantly increase the utilization of light.


An apparatus and method for singulating IC devices or semiconductor devices and/or components thereof. The apparatus includes a flexible membrane or bladder configured to receive an applied fluid pressure on a surface thereof and expand in response to the applied fluid pressure. Upon expansion of the flexible membrane, a semiconductor device or semiconductor device component is contacted by the flexible membrane and immobilized. The semiconductor device may then be subjected to a predetermined test or manufacturing operation. Subsequent any processing to the semiconductor device or component, the fluid pressure is released such that the flexible membrane contracts and releases the semiconductor device to be advanced for further processing, testing, or preparation for shipping.

1. Field of the Invention
The present invention relates generally to handling equipment for semiconductor and integrated circuit (IC) devices or semiconductor devices, such as different types of semiconductor die used as microprocessors, memory devices, etc., and the components thereof. More particularly the present invention relates to movement control and singulation of semiconductor devices during a manufacturing or testing process.
2. State of the Art
In the manufacture and testing of semiconductor devices, such as bare semiconductor die or packaged semiconductor die, the semiconductor devices, being either packaged or bare semiconductor die, are transferred through various locations and experience extensive handling. In performing specific tests or particular manufacturing operations, it is often required to separate a single semiconductor device from a plurality of similar semiconductor devices. This act of separation can and may be typically referred to as xe2x80x9csingulationxe2x80x9d. The singulation of a semiconductor device may be accomplished by various means. However, singulation is generally accomplished by implementing an actuating member to stop, advance, or otherwise manipulate a. semiconductor device in some manner with respect to one or more adjacent semiconductor devices. The actuating member is often one or more stop members in the form of pins, rods, cams or lever arms motivated by a pneumatic cylinder. In some alternative designs a solenoid or hydraulic cylinder may be employed.
Singulation for semiconductor die marking is one example of isolating a semiconductor device during the manufacturing process. In processing semiconductor devices for semiconductor die marking a plurality of semiconductor devices may be fed to a die marking station by placing them on an inclined track or pathway and feeding them toward the semiconductor die marking station in a serial fashion. Once an semiconductor device enters into a predetermine position on the track an actuation member, such as a pneumatic cylinder, may then contact the semiconductor device to hold it in a fixed position on the track, or alternatively the cylinder may move the semiconductor device to a new position and then hold it in place. Once the marking operation has taken place, the cylinder retracts and releases the semiconductor device for further processing, testing or packaging as may be required.
While processing semiconductor devices in such a manner is typically reliable, there are certain inefficiencies associated with such a method. For example, when using mechanical type cylinders, whether they be pneumatic, hydraulic or a solenoid, damage to the individual semiconductor devices is not only a possibility, it is at times a reality. The force of such actuators often mars or leaves marks on the surface of a device and may even cause functional or operational damage in certain instances. Also, in attempting to achieve greater efficiency, the cycle time of such mechanical devices may be increased which results in greater likelihood of damage due to the rapid deployment and impact with the semiconductor IC device or component. Additionally, such actuators require careful positioning such that contact, and thus likely damage, is not made with conductive elements of the semiconductor device. Direct and abrupt contact with the conductive elements would likely result in damage thereto possibly rendering the device inoperable. For this reason, actuators are typically positioned to avoid contact with the conductive balls or bumps on a ball grid array (BGA) type device.
Furthermore, pneumatic type cylinders and similar actuators require a certain amount of time to cycle through engagement and retraction, being limited by the high mass of the moving components. Thus, it becomes difficult to improve cyclical times in existing systems even if potential damage from impact of the actuators could be reduced.
In light of the shortcomings of the art, it would be advantageous to provide an apparatus and method for handling and singulating semiconductor devices, or semiconductor device components, which may assist in improving cyclical time of such singulation. It would also be advantageous to provide an apparatus and method which reduces or eliminates damage to the processed devices or components during singulation. Such an apparatus or method may advantageously be utilized in conjunction with various phases or aspects of semiconductor device production including both manufacturing and testing. Additionally, it would be advantageous to provide such an apparatus or method with the ability to contact conductive elements of the semiconductor devices without the risk of damage thereto.
In accordance with one aspect of the invention an apparatus for singulation of semiconductor devices or components thereof is provided. The apparatus includes two plates each having an opening passing therethrough. A flexible membrane is disposed between the two plates with the opening of each plate being substantially aligned with the other. The flexible membrane is configured to receive an applied fluid pressure adjacent the opening in the first plate and to extend outwardly through the opening of the second plate. The flexible membrane is also configured to contact and immobilize a semiconductor device moving adjacent the flexible membrane upon outward extension through the opening of the second plate.
The flexible membrane of the singulating apparatus may be formed of latex, rubber or another suitable material conducive to contacting an semiconductor device without marking or causing physical damage to the device. Use of the flexible material allows the apparatus to contact virtually any surface of the semiconductor device including conductive elements, such as the balls or bumps of a BGA type semiconductor device. The apparatus may also include additional openings to allow for the same membrane, or a separate membrane, to contact the same semiconductor device at a different surface location, to separate the first semiconductor device from a second semiconductor device, or to contact a second semiconductor device. Such a configuration may also be employed such that one flexible membrane contacts and immobilizes an semiconductor device or component while a second flexible membrane subsequently contacts the semiconductor device or component in such a manner so as to reposition it.
In accordance with another aspect of the invention, an apparatus is provided for singulating semiconductor components, such as, for example, die or lead frames. The apparatus includes a flexible membrane which is configured to receive an applied fluid pressure on a surface of the membrane such that it expands and contacts an semiconductor device moving adjacent to the membrane. The membrane serves to temporarily immobilize the semiconductor device component for a predetermined manufacturing or testing operation. As described above, the apparatus may be configured with multiple flexible membranes.
In accordance with another aspect of the present invention, an automated semiconductor device handler is provided. The handler includes an input location for receiving a plurality of semiconductor devices. A pathway, such as a gravity fed track, carries the semiconductor devices as they are advanced from the input location. A flexible membrane is located adjacent the pathway and is configured to receive an applied fluid pressure on a surface of the membrane such that the membrane extends toward and contacts an semiconductor device traveling along the pathway. As with the other aspects of the present invention, various features or techniques may be incorporated with the automated handler for further enhancement, or alternative implementation. For example, the handler may be coupled with a testing station wherein the flexible membrane contacts and immobilizes a semiconductor device in conjunction with the testing of the device. Similarly the handler might be used in conjunction with various manufacturing processes.
In accordance with yet another aspect of the present invention, a method of singulating semiconductor devices is provided. In accordance with the method, a plurality of semiconductor devices are advanced along a predetermined path. A flexible membrane is provided at a location adjacent the predetermined path in anticipation of singulating the semiconductor devices. A fluid pressure is applied to a surface of the membrane to effect an extension or expansion of the membrane towards the path. Upon proper extension or expansion of the membrane, a semiconductor device is contacted and immobilized thereby. The method may further include providing additional membranes. The additional membranes may be operated similarly to that described above for various purposes including physical separation of two or more devices.
In accordance with yet another aspect of the present invention, a method of testing semiconductor devices is provided. According to the method a plurality of semiconductor devices are advanced along a predetermined path. A flexible membrane is provided at a location adjacent the predetermined path in anticipation of singulating the semiconductor devices. A fluid pressure is applied to a surface of the membrane to effect an extension or expansion of the membrane towards the path. Upon proper extension or expansion of the membrane, a semiconductor device is contacted and immobilized such that the semiconductor device may be subjected to a predetermined test. The fluid pressure is released from the membrane allowing the membrane to retract from and release the semiconductor device in preparation of receiving and testing an additional device.
In accordance with yet another aspect of the present invention, a method of manufacturing a semiconductor device is provided. According to the presently considered method, a plurality of semiconductor devices are advanced along a predetermined path. A flexible membrane is provided at a location adjacent the predetermined path in anticipation of singulating the semiconductor devices. A fluid pressure is applied to a surface of the membrane to effect an extension or expansion of the membrane towards the path. Upon proper extension or expansion of the membrane, a semiconductor device is contacted and immobilized such that the semiconductor device may be subjected to a predetermined manufacturing operation. The fluid pressure is released from the membrane allowing the membrane to retract from and release the semiconductor device in preparation of receiving and performing the manufacturing operation to an additional device.

Bladder based package control/singulation


Embodiments of the present invention provide systems and methods for re-balancing the stability of a SRAM cell. Embodiments of the present invention identify SRAM cells with negative voltage threshold margins and write a “zero” state bit with in the bi-stable flip-flop of the SRAM. Raising the voltage of the CMOS set containing the “zero” state bit and selective transistor biasing, skews the “zero” state bit towards the complementary “one” state bit. This induces an increase voltage thresholds of the identified SRAM cells.

The present invention relates generally to array circuit designs, and more specifically to improving margins of the array circuit.
Complimentary metal-oxide semiconductor field-effect transistor (CMOS) technology is becoming increasingly miniaturized. This leads to complexities in designing static random access memory (SRAM). SRAM contains one or more arrays, wherein each array is a data structure composed of a collection of elements (e.g., values or variables) identified by at least one array index or key. During a write operation, the SRAM cell must flip in order to write new data in the cell. During a read operation, the SRAM cell must not flip in order to prevent data loss. There is only a certain area on the SRAM cell where reliable read and write operations are possible. Degradative processes, such as bias temperature instability (BTI), weaken n-type metal-oxide semiconductor (NMOS) field-effect transistors (FETs) and p-type metal-oxide semiconductor (PMOS) FETs. The SRAM cell stores bits (i.e., a basic unit of information in computing) as data storage elements using bi-stable latching circuitry. The bi-stable latching circuitry, which contain NMOS FETs and PMOS FETs, stores state information on each bit. The binary nature of these bits is represented in terms of two states—"zero" or "one." In other words, each bit is in the "zero" state or the "one" state.

This patent is subject to a terminal disclaimer.

International Business Machines Corporation


An electronic device is disclosed, which includes a touch display module, a frame for placing the touch display module, plural elastic pieces extended from a sidewall of the frame, a casing, a fastener, and plural adjusting screws. The fastener fastens the frame to the casing. The adjusting screws are inserted in the elastic pieces and are screwed in the casing. The depth of the adjusting screws screwed in the casing can be adjusted for adjusting a relative height between the touch display module and the casing.

1. Field of Invention
The present invention relates to an electronic device. More particularly, the present invention relates a electronic device with touch sensing function.
2. Description of Related Art
A modern touch display module has advantages, such as being user-friendly, fast response times, compact size, etc. The touch panel may provide users a convenient and intuitive way to manipulate an electronic device. Therefore, touch panels are widely used in all kinds of consumer electronics, e.g., e-books, personal digital assistants (PDAs), smart phones, laptop computers, point of sale (POS) systems, etc.
In general, a touch display module includes a display panel and a touch panel disposed on the display panel. A transparent touch sensor film is adhered on the display panel, so as to realize touch sensing and display functions at the same time.
With the development of the touch sensing device, the size of the touch panel is usually larger than the size of the display panel in order to provide better touch sensing feeling. One of the methods to fasten the touch display module on a casing is adhering the protruded edge of the touch panel on the casing. However, the cost and size of the touch panel are difficult to be reduced. Another method is firstly adhering the touch panel to the display panel and then assembling the touch display module to the casing. However, there would be a gap formed at an interface between the touch panel and the casing. Users may feel uncomfortable while fingers crossing the interface between the touch panel and the casing because of the gap.


A photoresist composition contains a photoacid generator and a polymer represented by the following formula:

1. Field of the Invention
This invention relates to a (meth)acrylate, a polymer, a photoresist composition, and a pattern forming process making use of the composition. More specifically, the present invention is concerned with a photoresist composition and a pattern forming process, which are suitable for use in a lithographic step in the fabrication of a semiconductor device, especially in lithography making use of radiation of 220 nm or shorter in wavelength as exposure radiation.
2. Description of the Related Art
In the field of fabrication of various electronic devices requiring small geometry processing of the half micron order and led by semiconductor devices, there is an ever-increasing demand toward devices of still higher density and integration. This has led to still severer requirements for lithographic technology which is adopted for the formation of submicrometer patterns.
As one of measures for achieving miniaturization of a pattern, there is an approach to shorten the wavelength of exposure radiation which is used upon formation of a resist pattern. For a mass-fabrication process of 256 Mb DRAMs (processing dimension: xe2x89xa60.25 xcexcm), use of KrF excimer laser (wavelength: 248 nm) of shorter wavelength than i-line (wavelength: 365 nm) as an exposure radiation source in place of i-line is positively considered these days.
However, a radiation source of a still shorter wavelength is considered to be needed for the fabrication of DRAMs having an integration degree of 1 Gb or higher which requires still smaller geometry processing technology (processing dimension: xe2x89xa60.18 xcexcm). In particular, use of photolithography making use of ArF excimer laser (wavelength: 193 nm) has been reported recently (Donald C. Hoffer, et al., Journal of Photopolymer Science and Technology, 9(3), 387-397 (1996).
There is accordingly an outstanding desire for the development of a resist which can be successfully employed in photolithography making use of ArF radiation. Such an ArF exposure resist is required to achieve an improvement in the cost performance of laser because, inter alia, the gas life of the excimer laser light source is short and a laser apparatus itself is expensive.
In addition to such a high resolution as permitting a still further reduction in the processing dimension, the ArF resist is also required to exhibit still higher sensitivity. As a method for providing a resist with higher sensitivity, chemical amplification making use of a photoacid generator as a sensitizer is known widely. As a representative example, JP Kokoku 2-27660 discloses a resist which is composed, in combination, of triphenylsulfonium hexafluoroarsenate and poly(p-tert-butoxycarbonyloxy-xcex1-methylstyrene). Chemical modification resists are now extensively employed as KrF eximer laser resists [for example, Hiroshi Ito, C. Grantwillson, American Chemical Society Symposium Series 242, 11-23 (1984)]. A chemically amplified resist is characterized in that protonic acid, which is generated from a photoacid generator as a component of the resist upon exposure to radiation, undergoes an acid-catalyzed reaction with a resist resin or the like when subjected to a heat treatment after the exposure. As a result, chemically amplified resists have attained far higher sensitivity over conventional resists the photoreaction efficiencies (reactions per photon) of which are lower than 1. Nowadays, most of newly developed resists are of the chemically amplified type, and the adoption of a chemical amplification mechanism has become indispensable in the development of a high-sensitivity material which can meet the trend toward an exposure radiation source of shorter wavelength.
In lithography making use of radiation of a short wavelength of 220 nm or shorter led by ArF eximer laser, however, a resin component of a chemically amplified photoresist for use in the formation of submicrometer patterns is required to have new properties unsatisfiable by conventional materials, that is, high transparency for exposure light of 220 nm or shorter and resistance to dry etching.
In the conventional lithography which uses g-beam (438 nm), i-line (365 nm) or KrF eximer laser (248 nm), a resin having an aromatic ring in its structural units, such as a novolac resin or poly(p-vinylphenol), is used as a resin component of a photoresist composition, so that the resin is allowed to exhibit resistance to etching owing to the dry etching resistance of these aromatic rings. However, a resin containing aromatic rings shows extremely strong absorption for radiation of a wavelength shorter than 220 nm. Exposure radiation is therefore mostly absorbed at a resist surface and is unable to pass to a substrate, so that no submicrometer resist pattern can be formed. Conventional resins cannot accordingly be applied to photolithography which makes use of short-wavelength radiation of 220 nm or shorter. As a consequence, there is an outstanding strong desire for a resin material which does not contain aromatic rings, has etching resistance, and is transparent to wavelengths of 220 nm and shorter.
Proposed examples of high molecular compounds having transparency to ArF eximer laser (193 nm) and dry etching resistance include a copolymer containing adamantyl methacrylate units, which is an alicyclic polymer [Takechi, et al., Journal of Photopolymer Science and Technology, 5(3), 439-446 (1992)], a copolymer containing isobornyl methacrylate units [R. D. Allen, et al., Journal of Photopolymer Science and Technology, 8(4), 623-636 (1995); ibid., 9(3), 465-474 (1996)], and a copolymer containing menthyl methacrylate units [Shida, et al., Journal of Photopolymer Science and Technology, 9(3), 457-464 (1996)].
In the above-exemplified resins, however, adamantyl-containing residue units, isobornyl-containing residue units or menthyl-containing residue unitsxe2x80x94which possess dry etching resistancexe2x80x94do not contain residual groups which can exhibit a difference between the solubility before exposure and that after the exposure. In addition, these alicyclic groups do not contain groups (for example, carboxyl groups) which provide the resins with solubility in an aqueous alkaline solution and also with adhesion to substrates. Accordingly, a homopolymer of a monomer containing an alicyclic group has high hydrophobicity and poor adhesion to substrates under processing (for example, silicon substrates) and can hardly form uniform coating films with good reproducibility. Moreover, due to the lack of any residual groups which make it possible to exhibit a difference between a dissolution rate before exposure and that after the exposure, no pattern can be formed by exposure. The above-described resins can hence be used as resin components in resists only when they are converted into copolymers with a comonomer capable of exhibiting a difference in solubility, such as t-butyl methacrylate or tetrahydropyranyl methacrylate, or with a comonomer capable of imparting substrate adhesion such as methacrylic acid. These comonomers have considerably low dry etching resistance and, nonetheless, their contents are required to be as high as about 50 mole %. Accordingly, such copolymers are significantly reduced in dry etching resistance and have little utility as dry-etching-resistant resins.
There is accordingly a strong desire for a new resist resin material, which has high transparency to radiation of 220 nm or shorter, possesses high etching resistance, contains functional groups permitting exhibition of a difference between the solubility before exposure and that after the exposure, permits development in an aqueous alkaline solution after exposure, and is equipped with improved substrate adhesion.
As a novel resin capable of satisfying these requirements, the present inventors already developed the resin disclosed in JP Kokai 8-259626. A further improvement in dry etching resistance is however desired.
An object of the present invention is therefore to provide a chemically amplified photoresist compositionxe2x80x94which is suitable for use in lithography making use of exposure radiation of 220 nm or shorter, especially of 180 to 220 nm, can exhibit a difference between the solubility before exposure and that after the exposure, permits development in an aqueous alkaline solution after exposure, possesses high substrate adhesion, has high transparency to radiation of 220 nm or shorter, and is equipped with improved etching resistancexe2x80x94and also to provide a pattern forming process making use of the photoresist composition.
The present invention thus relates to a (meth)acrylate represented by the following formula (1):
wherein R1 represents a hydrogen atom or a methyl group, R2 represents a C17-23 divalent hydrocarbon group containing a bridged cyclic hydrocarbon group, and R3 represents an acid-decomposable group or a hydrogen atom.
This invention also pertains to a polymer available by homopolymerization of the (meth)acrylate represented by the formula (1) or copolymerization of the (meth)acrylate with another copolymerizable compound and having a weight average molecular weight of from 1,000 to 500,000.
This invention is also concerned with a polymer represented by the following formula (2):
wherein R4, R6 and R9 each represents a hydrogen atom or a methyl group, R5 and R7 each represents a C17-23 divalent hydrocarbon group containing a bridged cyclic hydrocarbon group, R8 represents an acid-decomposable group, R10 represents a hydrogen atom or a C1-12 hydrocarbon group, x+y+z equals to 1, and x, y and z stand for 0 to 1, 0 to 1, and 0 to 0.9, respectively, and having a weight average molecular weight of from 1,000 to 500,000.
This invention also relates to a photoresist composition comprising 70 to 99.8 wt. % of one of the above-described polymers of the present invention and 0.2 to 30 wt. % of a photoacid generator capable of generating an acid upon exposure to radiation.
According to the present invention, it is possible to provide a photoresist material, which can exhibit a difference between the solubility before exposure and that after the exposure, permits development in an aqueous alkaline solution after exposure, possesses high substrate adhesion, has high transparency to radiation of 220 nm or shorter, and is equipped with excellent etching resistance, thereby making it possible to form submicrometer patterns by ArF eximer laser beam in the fabrication of semiconductor devices.
The present invention will hereinafter be described in detail by its embodiments.
In the formula (1), R1 represents a hydrogen atom or a methyl group, and R2 represents a C17-23 divalent hydrocarbon group containing a bridged cyclic hydrocarbon group. Specific examples of R2 can include hexacyclo[18.104.22.168,6.110,13.02,7.09,14]heptadecanediyl, methylhexacyclo[18.104.22.168,6.110,13.02,7.09,14]heptadecanediyl, octacyclo[184.108.40.206,9.14,7.111,18.113,16. 03,8.012,17]docosanediyl, methyloctacyclo[220.127.116.11,9.14,7.111,18.113,16.03,8.012,17]docosanediyl groups, as shown in Table 1.
R3 represents a hydrogen atom or an acid-decomposable group. Specific examples can include t-butyl, tetrahydropyran-2-yl, tetrahydrofuran-2-yl, 4-methoxytetrahydropyran-4-yl, 1-ethoxyethyl, 1-butoxy-ethyl, 1-propoxyethyl, and 3-oxocyclohexyl groups.
As an example of polymers available by homopolymerization of the (meth)acrylate represented by the formula (1) or copolymerization of the (meth)acrylate with another copolymerizable compound, the polymer represented by the formula (2) can be mentioned.
In the formula (2), R4, R6 and R9 each represents a hydrogen atom or a methyl group. R5 and R7 each represents a C17-23 divalent hydrocarbon group containing a bridged cyclic hydrocarbon group. Specific examples can include hexacyclo[22.214.171.124,6.110,13.02,7.09,14]heptadecanediyl, methylhexacyclo[22.214.171.124,6.110,13.02,7.09,14]heptadecanediyl, octacyclo[18.104.22.168,9.14,7.111,18.113,16.03,8.012,17]docosanediyl and methyloctacyclo[18.104.22.168,9.14,7.111,18.113,16.03,8.012,17]docosanediyl groups, as shown in Table 1.
R8 represents an acid-decomposable group. Specific examples can include t-butyl, tetrahydropyran-2-yl, tetrahydrofuran-2-yl, 4-methoxytetrahydropyran-4-yl, 1-ethoxyethyl, 1-butoxyethyl, 1-propoxyethyl, and 3-oxocyclohexyl groups.
R10 represents a hydrogen atom or a C1-12 hydrocarbon group. Specific examples can include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, cyclohexyl, dimethylcyclohexyl, tricyclo[5.2.1.02,6]decyl, norbonyl, adamantyl, and isobornyl groups.
Among (meth)acrylates represented by the formula (1), a vinyl monomer of the formula (1) in which R1 is a methyl group, R2 is a hexacyclo[126.96.36.199,6.110,13.02,7.09,14]heptadecanediyl group, and R3 is a tetrahydropyran-2-yl group can be synthesized, for example, as will be described hereinafter.
First, 8-methoxycarbonyltetracyclo[126.96.36.199,5.17,10]-3-dodecene and dicyclopentadiene are reacted at 170 to 180xc2x0 C. for 17 hours, whereby methoxycarbonylhexacyclo[18.104.22.168,6.110,13.02,7.09,14]heptadecene is obtained.
The methoxycarbonylhexacyclo[184.108.40.206,6.110,13.02,7.09,14]heptadecene is next subjected to alkaline hydrolysis, followed by the protection of the carboxyl group with a tetrahydropyranyl group so that tetrahydropyranyloxycarbonylhexacyclo[18.104.22.168,6.110,13.02,7.09,14] is obtained.
Further, one hydroxyl group is introduced per molecule by using a boran-tetrahydrofuran complex, followed by the reaction with methacryloyl chloride, whereby the target methacrylate is obtained.
The polymer, which is available by homopolymerization of the (meth)acrylate represented by the formula (1) or copolymerization of the (meth)acrylate represented by the formula (1) with another copolymerizable compound, can be obtained by a conventional polymerization process such as radical polymerization or ionic polymerization. This polymerization can be conducted, for example, by stirring the (meth)acrylate by itself or in combination with the another copolymerizable monomer under heat at 50 to 70xc2x0 C. for 0.5 to 12 hours in dry tetrahydrofuran under an atmosphere of an inert gas (argon, nitrogen or the like) in the presence of a suitable radical polymerization initiator [for example, azobisisobutyronitrile (AIBN); monomer/initiator molar ratio: 8 to 200] added therein.
Further, the weight average molecular weight of the polymer according to the present invention ranges from 1,000 to 500,000, with 5,000 to 200,000 being more preferred. A copolymer having desired composition, molecular weight and the like can be obtained by choosing the charge ratio of monomers for the copolymer and other polymerization conditions.
The photoacid generator, which is an essential element of each photoresist composition according to the present invention, may desirably be a photochemical acid generator which generates an acid upon exposure to radiation of 400 nm or shorter, preferably radiation in a range of from 180 nm to 220 nm. Any photoacid generator is usable, insofar as its mixture with the above-described high molecular compound or the like in the present invention is sufficiently soluble in an organic solvent and the resulting solution can be formed into a uniform coating film by a film-forming method such as spin coating. Such photochemical acid generators can be used either singly or in combination.
Examples of photoacid generators usable in the present invention can include the triphenylsulfonium salt derivatives described by J. V. Crivello et al. in Journal of the Organic Chemistry, 43(15), 3055-3058 (1978), onium salts including the triphenylsulfonium salt derivatives as typical examples (for example, compounds such as sulfonium salts, iodonium salts, phosphonium salts, diazonium salts and ammonium salts), 2,6-dinitrobenzyl esters [O. Nalamasu, et al., SPIE Proceedings, 1262, 32 (1990)], 1,2,3-tri(methane-sulfonyloxy)benzene (Takumi Ueno, et al., Proceedings of PME ""89, 413-424, Kodansha Ltd. (1990)3, and sulfo-succimides disclosed in JP Kokai 5-134416.
The content of the photoacid generator is generally from 0.2 to 30 parts by weight, preferably from 1 to 15 parts by weight per 100 parts of the whole components including itself. A content smaller than 0.2 part by weight may lead to a significant reduction in sensitivity, thereby making it difficult to form patterns. On the other hand, a content greater than 30 parts by weight may develop problems such that the formation of a uniform coating film becomes difficult and a residue (scam) tends to occur after development.
The content of the polymer is generally from 70 to 99.8 parts by weight, preferably 85 to 99 parts by weight per 100 parts by weight of the whole components including itself.
Any solvent can be used suitably in the present invention, insofar as it is an organic solvent capable of achieving sufficient dissolution of the polymer and the photoacid generator and the resulting solution can be formed into a uniform coating film by a coating method such as spin coating. Such solvents can be used either singly or in combination. Specific examples can include, but are not limited to, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, tert-butyl alcohol, methylcellosolve acetate, ethylcellosolve acetate, propylene glycol monoethyl ether acetate, methyl lactate, ethyl lactate, 2-methoxybutyl acetate, 2-ethoxyethyl acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, N-methyl-2-pyrrolidinone, cyclohexanone, cyclopentanone, cyclohexanol, methyl ethyl ketone, 1,4-dioxane, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monomethyl ether, and diethylene glycol dimethyl ether.
Although the xe2x80x9cbasicxe2x80x9d components of the photoresist composition of the present invention are the above-described photoacid generator, resin and solvent, one or more of other components such as dissolution inhibitors, surfactant, pigments, stabilizers, coating property improvers and dyes may also be added as needed.
Each photoresist composition according to the present invention is usable as a new photoresist material having high transparency to radiation of 220 nm or shorter, high dry etching resistance and improved substrate adhesion. Use of the photoresist composition according to the present invention in lithography making use of far ultraviolet radiation of 220 nm or shorter as exposure radiation makes it possible to form submicrometer patterns.
The present invention also relates to process for forming a pattern, which comprises the following steps: coating a substrate with the photoresist composition of the present invention, exposing the thus-coated photoresist composition to radiation having a wavelength of from 180 to 220 nm, baking the thus-exposed photoresist composition, and then developing the thus-baked photoresist composition. In this process, prebaking may be conducted after the coating step if desired. Further, the exposure radiation may desirably be ArF eximer laser.
The present invention will hereinafter be described further by Examples. It is however to be noted that the present invention is not limited to or by them.

(Meth)acrylate, polymer, photoresist composition, and pattern forming process making use of the composition

Abstract: wherein R4, R6 and R9 each represents a hydrogen atom or a methyl group, R5 and R7 each represents a C17-23 divalent hydrocarbon group containing a bridged cyclic hydrocarbon group, R8 represents an acid-decomposable group, R10 represents a hydrogen atom or a C1-12 hydrocarbon group, x+y+z equals to 1, and x, y and z stand for 0 to 1, 0 to 1, and 0 to 0.9, respectively, and having a weight average molecular weight of from 1,000 to 500,000. According to the present invention, a chemical modification photoresist composition having high transparency to radiation of 220 nm and shorter and improved in etching resistance can be provided.


A wear-resistant coating, capable of imparting excellent wear resistance to a silent chain, comprises a base coating consisting of a hard inorganic material having interspersed particles of a hard inorganic material different from the inorganic material of the base coating. A part of the interspersed particles is exposed on the surface of the coating. The coating has superior oil-retaining properties as a result of gaps formed at the interface between the particles and the base coating, and the superior oil-retaining properties contribute to the wear-resistance of the coating.

In recent years, silent chains have been used for power transmission under high speed and high load conditions. In a typical silent chain, a number of link plates P, each bifurcated to provide a pair of teeth on one side, are arranged in interleaved layers connected to one another by connecting pins Q as shown in FIG. 3. On the bifurcated portion of each of the link plates P, two outside flank surfaces R1 function as meshing surfaces in an outer flank meshing silent chain, or two inside flank surfaces R2 serve as meshing surfaces in an inner flank meshing silent chain. In either case, the meshing surfaces mesh with sprockets, and transmit power from the chain to the sprockets or from the sprockets to the chain. Even if the pitch of the chain is extended, close contact between the link plate and the sprocket is maintained. Accordingly, these silent chains produce little noise, and are suitable for high speed operation and for applications in which quiet operation is required.
Since these silent chains are used at high speed and under high load, in order to improve wear-resistance, a sliding surface of a chain is provided with a coating of hard inorganic material such as titanium carbide (TiC), vanadium carbide (VC) or the like by a CVD process, a PVD process, spray coating, diffusion coating, or the like,.
To improve wear-resistance, it has been proposed to form, on a surface of a silent chain, a chromium iron alloy layer having diffused chromium carbide particles, so that the surface has enhanced hardness while maintaining toughness.
However, where a coating of the above-mentioned hard inorganic material was provided on the surface of a silent chain, several problems were encountered. The load on the coated surface, and the sliding speed, were extremely large, and when foreign substances such as worn powder and the like were increased as a result of the use of a lubricating oil on the coated surface over a long time, the coated surface served as a boundary, causing an increase in temperature. Oxidation of the coated surface resulted, and sufficient wear resistance could not be obtained.
As described in Japanese Laid-open Patent Publication No. Sho. 57-85967, when a chromium-iron alloy layer with diffused chromium carbide particles is formed on a surface of the silent chain by subjecting the surface to a chromizing process, the hardness of the surface is improved by the particles of chromium carbide. However, since the chromium-iron alloy layer forming a base coated layer is a metal, the layer does not have sufficient wear-resistance. Additionally, in recent years, improved wear-resistance has been required in silent chains used in engines because of demand for high speed operation and long service life.
Accordingly, the objects of the invention are to solve the above-mentioned prior art problems and to provide a wear-resistant coating having excellent lubricating oil-retention properties, and to provide a coated silent chain having excellent wear-resistance.

Wear-resistant coating and silent chain coated with same


A method and apparatus for recovering the phase of a symbol clock operating at a predetermined symbol rate is described. A modulated RF signal which has been downconverted or a modulated baseband signal is filtered and sampled by a high speed converter. A high speed digital signal processor processes the digitized signal to determine the phase of the symbol clock. The symbol phase is determined independent of carrier phase by repetitively resampling the digitized signal and constructing the histogram for each resample of that signal. By comparing the histograms of each resample the symbol phase may be identified. Using the symbol rate and phase, the signal may be analyzed for carrier phase and frequency errors and modulation accuracy using eye diagrams, modulation trajectories and symbol content.

1. Field of the Invention
The present invention relates generally to communication systems which use digital modulation techniques, such as QAM, QPSK and OQPSK, and more specifically to instrumentation for measuring and troubleshooting modulation problems and errors.
2. Description of Related Art
There is presently a shift in modern communication systems from analog modulation methods to digital modulation methods. This is driven by the ever-increasing need to drive more information through narrower channels of the RF spectrum and for computers to communicate between themselves. While the design of each communication system is driven by its own particular needs, there have developed a general set of digital modulation schemes including, M-ary PSK modulation schemes and M-try quadrature amplitude modulation (QAM) schemes. Such methods include, among others, quadrature phase shift keying (QPSK), offset quadrature phase shift keying (OQPSK).
The bandwidth efficiency of these systems may be maximized using a group of theorems developed by Nyquist, including the Nyquist Minimum-Bandwidth Theorem and the Nyquist Intersymbol Interference and Jitter Free Transmission Theorem. The theorems describe a method of spreading the energy of one symbol over the period of time used to transmit several symbols without creating intersymbol interference. These theorems may be implemented using a system of filters which are generally referred to as Nyquist filters. Nyquist filters generate considerable distortion except in the regions in the immediate neighborhood of the "sampling instants" or "null points" determined by a symbol clock. If the symbol clock is known, including both its rate and phase, then the symbol clock may be used to recover the binary signal and to drive a display to generate eye diagrams and constellation diagrams. The size of the eye in the eye diagram and the stability of the constellation diagram are useful measures of the communication system operating margins. Unstable eye patterns and constellation diagrams may be used to diagnose modulation or other system problems, such as unstable carriers.
Digital demodulators for M-ary PSK modulated signals must use coherent detection. Coherent detectors require an exact replica of the carrier, in both frequency and phase. Any errors in this carrier replica, either in frequency or phase, can cause significant errors in the later stages of the receiver. Coherent detection of digitally modulated signals is subject to a well known carrier phase ambiguity. This may be most easily demonstrated by considering the constellation for a particular modulation scheme. If the constellation is rotated by phase errors between the actual carrier and the replica carrier, for certain angles of rotation, there is no way that the demodulator in the receiver can distinguish the rotated constellation from a valid constellation without some knowledge of the data. These ambiguities may be overcome by additional information from the data itself, for example, a short preamble, or through differential coding. Certain modulation schemes have an inherent symbol phase ambiguity, for example, OQPSK. For OQPSK, there are two clock transitions, an I transition and a Q transition, causing symbol phase uncertainty. Symbol phase ambiguities are additive with the carrier phase ambiguities complicating demodulation. When coherent demodulators are used to demodulate these signals, additional information from the data itself or differential coding must be used to remove the ambiguity.
Since in most systems the receiver timing is independent of transmitter timing, the carrier frequency and phase must be derived from the transmitted signal. Generally, the replica carrier is generated using a narrow band phase-locked loop. Two general approaches exist to provide a phase reference to "lock" this loop, conventional approaches and data directed approaches. Conventional approaches, for example, frequency doubling, frequency quadrupling and Costas loops, multiply the transmitted signal in order to generate a coherent phase reference. Data directed demodulators derive symbol timing information from the signal and use that information to generate a coherent phase reference. Conventional approaches require a long data transmission to generate the coherent phase reference. In modern digital communication systems, short bursts are increasingly being used. These burst are often too short for conventional approaches to "lock". The data directed approaches can obtain the required phase information more quickly and therefore will "lock" more quickly. Therefore, data directed approaches are also better suited for test equipment.
Existing data directed approaches have relied on the existence of a spectral component or "spectral lines" in the modulated signal or on a unique segment or "preamble" in the modulated signal to acquire the needed symbol timing information. However, modulation schemes and some system situations are incompatible with these approaches. Staggered M-ary PSK modulated signals do not have a useable spectral line component, because it is very weak. Many modulated signals do not have long preambles. Finally, any distortion and noise in the transmission system can sometimes cause problems detecting the spectral information. Therefore, there exists a need for a more robust technique for acquiring the required symbol timing information for data directed demodulators.

Method and apparatus for symbol clock phase recovery


Encoding and decoding a video using transformation index that indicates information that indicates a structure of a transformation unit transforming data of a current coding unit.

1. Field
The exemplary embodiments relate to video encoding and video decoding in which transformation between a spatial domain and a transformation domain is performed.
2. Description of the Related Art
As hardware for reproducing and storing high resolution or high quality video content is being developed and supplied, a need for a video codec for effectively encoding or decoding the high resolution or high quality video content is increasing. In a conventional video codec, a video is encoded according to a limited encoding method based on a macroblock having a predetermined size. In the conventional video codec, video data is encoded and decoded by performing transformation and inverse transformation on macroblocks by using blocks each having the same size.

Method and apparatus for encoding video by using transformation index, and method and apparatus for decoding video by using transformation index


A self-aligning hybridization method enabling small pixel pitch hybridizations with self-alignment and run-out protection. The method requires providing a first IC, the surface of which includes at least one electrical contact for connection to a mating IC, depositing an insulating layer on the IC's surface, patterning and etching the insulating layer to provide recesses in the insulating layer above each of the electrical contacts, and depositing a deformable conductive material in each of the recesses. A mating IC is provided which includes conductive pins positioned to align with the deformable conductive material in respective ones of the recesses on the first chip. The first and mating ICs are then hybridized by bringing the conductive pins into contact with the deformable conductive material in the recesses, such that the conductive material deforms and the pins make electrical contact with the first IC's electrical contacts.

1. Field of the Invention
This invention relates generally to methods of interconnecting multiple chips to form a hybrid device, and more particularly to a self-aligning hybridization method which is well-suited for small pixel pitch applications.
2. Description of the Related Art
A "hybrid" device typically contain two or more separately-fabricated integrated circuits (ICs or "chips") within a common package. Generally, the separate chips must be interconnected in some fashion to provide a functional device. The techniques used to facilitate the interconnection is commonly referred to "hybridization".
The chips within a given hybrid are often in a 'stacked' arrangement, with an interconnection means employed between the chips to connect contact pads on the top of the lower chip with corresponding contact pads on the bottom of the upper chip. One common hybridization technique uses indium bumps deposited on both chips' mating surfaces. The chips are then brought into contact with each other such that the bumps are pressed together, causing them to deform and bond together. However, there is no means of ensuring the alignment of the respective indium bumps; in fact, in practice, the bumps are often out of alignment and slip off each other.
Another problem with this conventional hybridization technique is 'run-out'. An indium bump is typically around 10 μm in diameter before being deformed as described above, with a target compression of about 50%. When pressed together, the diameter of the bump(s) expands, which is known as run-out. However, the indium can deform too much or in unpredictable directions, which can lead to shorts when adjacent contacts are in close proximity to each other. For example, a hybrid detector device typically includes a first chip containing a large array of pixels, each of which must interface with a second, control IC. The distance between the centerlines of adjacent pixels is referred to as 'pixel pitch'. As pixel pitch drops below 10 μm, both indium run-out and hybridization alignment can make existing methods of interconnecting the chips unsuitable.
One approach to mitigating these problems is offered by DRS Technologies, who describe a fine-pitch bump technology in which one chip mating surface has metal pads in respective recesses, and the other mating surface has indium bumps which are intended to contact the metal pads when the chips are brought together. However, there is still no means of ensuring the alignment of the indium bumps with the metal pads.


An output buffer circuit comprises a P channel MOS transistor connected between a power supply terminal and an output terminal, an N channel MOS transistor connected between a ground terminal and an output terminal, a capacitance connected to a ground terminal, and a switch formed of an N channel MOS transistor connected between the output terminal and the capacitance. In charging a load, first, charge stored in the capacitance is supplied to the output terminal, and subsequently the P channel MOS transistor is turned on. In discharging the load, first, charge is supplied from the output terminal to the capacitance, and subsequently the N channel MOS transistor is turned on.

1. Field of the Invention
This invention relates to an output buffer circuit, and more particularly, to reducing power consumption of an output buffer circuit.
2. Description of the Background Art
Outputs of various circuits such as logic circuits and memory circuits are provided with output buffer circuits in order to increase load driving capability. FIG. 7 is a circuit diagram showing one example of a configuration of a conventional buffer circuit.
In FIG. 7, an output buffer circuit 10a has an input terminal 13 receiving signals from various circuits and an output terminal 14 for producing output signals. An external load 20 is connected to output terminal 14. Output buffer circuit 10a comprises a pull-up transistor formed of a P channel MOS transistor and a pull-down transistor formed of an N channel MOS transistor. Pull-up transistor 11 is connected between a power supply terminal 15 and output terminal 14. A pull-down transistor 12 is connected between a ground terminal and output terminal 14. The gates of pull-up transistor 11 and pull-down transistor 12 are connected to an input terminal 13. External load 20 comprises an external load capacitance 21 and an external load resistance 22.
When a signal applied to input terminal 13 is at "L" (low logic level), pull-up transistor 11 is turned on and pull-down transistor 12 is turned off. As a result, an output signal derived from output terminal 14 attains "H" (high logic level), and external load capacitance 21 is charged. When a signal applied to input terminal 13 is at "H", pull-up transistor 11 is turned off and pull-down transistor 12 is turned on. As a result, an output signal derived from output terminal 14 falls down to "L" and external load capacitance 21 is discharged.
Pull-up transistor 11 and pull-down transistor 12 are normally about ten times the size of the smallest transistor in a semiconductor integrated circuit, so that the load driving capability increases.
As mentioned above, in a conventional output buffer circuit, charging current and discharging current for an external load capacitance 21 all flow through pull-up transistor 11 or pull-down transistor 12, so that a problem exists that power consumption increases due to heat loss of transistor resistance.

Output buffer circuit and method of operation thereof with reduced power consumption


Method and apparatus that provide for broadcast multicast services in an ultra mobile broadband network are disclosed. A broadcast transmission structure provides for efficient indexing of subbands reserved for BCMCS. Transmissions on the logical channels are segmented into error control blocks beginning with zero or one MAC packet received by a MAC layer. A transmitting entity appends parameters relating to content change within a next ultraframe at end of every broadcast packet that is not a stuffing packet. A mapping message of multiple Physical Layer groups addresses a single logical channel when SFN (Single Frequency Network) coverage of an associated subband group is different from SFN coverage of the logical channel.

Wireless communication systems are widely deployed to provide various types of communication content, such as, voice, media, data, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, 3GPP LTE systems, and orthogonal frequency division multiple access (OFDMA) systems.
Generally, a wireless multiple-access communication system can concurrently support communication for multiple wireless terminals. Each terminal communicates with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to a communication link from base stations to terminals, and the reverse link (or uplink) refers to a communication link from terminals to base stations. This communication link may be established via one or more of single-in-single-out (SISO), multiple-in-single-out (MISO) or multiple-in-multiple-out (MIMO) systems.
A wireless communication system can also be employed to provide various types of services. These services include point-to-point services, or dedicated services such as voice and packet data, whereby data is transmitted from a transmission source (e.g., a base station) to a specific recipient terminal such as in cellular telephony or Internet communications. In addition to these services, several providers have launched mobile multimedia services closely resembling traditional broadcast services such as radio, television etc. Such services push content aggregated into channels to subscribers. In some cases, the content may be taken from, for example, existing TV channels or it may be other special content.
If the point-to-point model of communications is employed for such mobile multimedia services the content server that delivers content to the users must establish and maintain a separate point-to-point connection for each recipient. While this approach may be adequate for low to moderate number of subscribers it does not scale well as the number of subscribers increases. Thus, the characteristics and requirements for point to multipoint transmissions such as multimedia services or broadcast services are very different in many aspects from those for more dedicated services such as cellular telephony. For example, dedicated resources (e.g., physical channels) are allocated to individual terminals for dedicated services. In contrast, common resources may be allocated and used for all terminals expected to receive the broadcast services. Moreover, the transmission for a broadcast service would need to be controlled such that a large number of terminals with different individual attributes are able to reliably receive the service, while optimizing the resources required for implementing the service. Hence, techniques to implement such broadcast services efficiently in a wireless communication system need to be explored that allow reservation of bandwidth for broadcast services, operating flexibility depending on broadcast/multicast loads, fast switching time, and minimal wake up time for access terminals thus improving battery efficiency.

Method and apparatus for using a MAC protocol for broadcast