Patents by Inventor Chandra Sekar
Chandra Sekar has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7736455Abstract: A method for improving strength of the finished product in paint roller manufacturing processes and other continuous processes for producing tubular goods from polymers. The method utilizes a substrate such as a polypropylene strip with grooves on its surface. The grooved substrate is fed onto a mandrel to form a tube. Adhesive is applied upon the grooved surface of the grooved substrate. A cover may be applied about the tube, and the resulting product is then cut into finished-size paint rollers. The hardened adhesive in the grooves may operate to reduce the hoop-force which would otherwise tend to unwind the wound substrate. The method in certain embodiments provides a reduction in cost and weight of the finished product.Type: GrantFiled: June 26, 2008Date of Patent: June 15, 2010Inventors: Chandra Sekar, Adam B. Landa
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Publication number: 20100129433Abstract: A proteoliposome, which is obtained by removing a surfactant from a mixed solution including lipid, membrane proteins and the surfactant, wherein the content of the surfactant in the mixed solution is equal to or more than 1.5 times of the sum of a maximum amount of the surfactant associating with the lipid and a maximum amount of the surfactant associating with the membrane protein. A biochip wherein the above-described proteoliposome is spread on a substrate. A method for producing a proteoliposome by removing a surfactant from a mixed solution including lipid, membrane proteins and the surfactant, wherein the content of the surfactant in the mixed solution is made equal to or more than the sum of a maximum amount of the surfactant associating with the lipid and a maximum amount of the surfactant associating with the membrane protein.Type: ApplicationFiled: November 26, 2008Publication date: May 27, 2010Applicants: Nippon Telegraph and Telephone Corporation, Isis Innovation Ltd.Inventors: Nahoko Kasai, Chandra Sekar Ramanujan, Keiichi Torimitsu, John F. Ryan
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Publication number: 20100130382Abstract: A liposome comprising a region of a lipid bilayer membrane with different membrane thicknesses, wherein each lipid bilayer membrane region is composed of a different lipid, and a thick membrane side in the region of the lipid bilayer membrane is formed of lipid having a phase transition temperature higher than that of the lipid forming a thin membrane side in the region of the lipid bilayer membrane. A proteoliposome, wherein the above-described liposome includes membrane proteins. A biochip, wherein the above-described liposome or the above-described proteoliposome is spread on a substrate. The above-described biochip, wherein the substrate includes at least one kind selected from the group consisting of mica, SiO2, SiN, Au and Pt.Type: ApplicationFiled: November 26, 2008Publication date: May 27, 2010Applicants: Nippon Telegraph and Telephone Corporation, Isis Innovation Ltd.Inventors: Chandra Sekar Ramanujan, Nahoko Kasai, Keiichi Torimitsu, John F. Ryan
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Publication number: 20090320994Abstract: A method for reducing cost and weight in paint roller manufacturing processes and other continuous processes for producing tubular goods from polymers. The method may utilize a perforated substrate such as a perforated polypropylene strip or may include a perforating step which removes overage from an unperforated substrate. An unperforated substrate, which may be of a thinner gauge than the perforated substrate, is fed onto a mandrel. The perforated substrate is fed onto the unperforated substrate to form a tube. Adhesive is applied upon the outer surface of the perforated substrate. A cover may be applied about the tube, and the resulting product is then cut into finished-size paint rollers. The removal of the overage results in a reduction in the weight of the paint roller. In certain embodiments the overage from a perforation step is collected, and may be reused in a subsequent implementation of the method or resold.Type: ApplicationFiled: August 28, 2008Publication date: December 31, 2009Inventor: Chandra Sekar
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Publication number: 20090320999Abstract: A method for improving strength of the finished product in paint roller manufacturing processes and other continuous processes for producing tubular goods from polymers. The method utilizes a substrate such as a polypropylene strip with grooves on its surface. The grooved substrate is fed onto a mandrel to form a tube. Adhesive is applied upon the grooved surface of the grooved substrate. A cover may be applied about the tube, and the resulting product is then cut into finished-size paint rollers. The hardened adhesive in the grooves may operate to reduce the hoop-force which would otherwise tend to unwind the wound substrate. The method in certain embodiments provides a reduction in cost and weight of the finished product.Type: ApplicationFiled: June 26, 2008Publication date: December 31, 2009Inventors: Chandra Sekar, Adam B. Landa
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Publication number: 20090321007Abstract: A method for reducing cost and weight in paint roller manufacturing processes and other continuous processes for producing tubular goods from polymers. The method may utilize a perforated substrate such as a perforated polypropylene strip or may include a perforating step which removes overage from an unperforated substrate. The perforated substrate is fed onto a mandrel to form a tube. Adhesive is applied upon the outer surface of the perforated substrate. A cover may be applied about the tube, and the resulting product is then cut into finished-size paint rollers. The removal of the overage results in a reduction in the weight of the paint roller. In certain embodiments the overage from a perforation step is collected, and may be reused in a subsequent implementation of the method or resold.Type: ApplicationFiled: June 26, 2008Publication date: December 31, 2009Inventor: Chandra Sekar
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Patent number: 7606071Abstract: A source line bias error caused by a voltage drop in a source line of a non-volatile memory device during a read or verify operation is addressed. In one approach, a body bias is applied to a substrate of the non-volatile memory device by coupling the substrate to a source voltage or a voltage which is a function of the source voltage. In another approach, a control gate voltage and/or drain voltage, e.g., bit line voltage, are compensated by referencing them to a voltage which is based on the source voltage instead of to ground. Various combinations of these approaches can be used as well. During other operations, such as programming, erase-verify and sensing of negative threshold voltages, the source line bias error is not present, so there is no need for a bias or compensation. A forward body bias can also be compensated.Type: GrantFiled: April 24, 2007Date of Patent: October 20, 2009Assignee: SanDisk CorporationInventors: Deepak Chandra Sekar, Nima Mokhlesi, Hao Thai Nguyen, Seungpil Lee, Man Lung Mui
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Patent number: 7606079Abstract: Power consumption in a non-volatile storage device is reduced by providing reduced read pass voltages on unselected word lines during a read operation. A programming status of one or more unselected word lines which are after a selected word line on which storage elements are being read is checked to determine whether the unselected word lines contain programmed storage elements. When an unprogrammed word line is identified, reduced read pass voltages are provided on that word line and other word lines which are after that word line in a programming order. The programming status can be determined by a flag stored in the word line, for instance, or by reading the word line at the lowest read state. The unselected word lines which are checked can be predetermined in a set of word lines, or determined adaptively based on a position of the selected word line.Type: GrantFiled: April 25, 2007Date of Patent: October 20, 2009Assignee: SanDisk CorporationInventors: Deepak Chandra Sekar, Nima Mokhlesi, Hock C. So
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Patent number: 7606072Abstract: A source line bias error caused by a voltage drop in a source line of a non-volatile memory device during a read or verify operation is addressed. In one approach, a body bias is applied to a substrate of the non-volatile memory device by coupling the substrate to a source voltage or a voltage which is a function of the source voltage. In another approach, a control gate voltage and/or drain voltage, e.g., bit line voltage, are compensated by referencing them to a voltage which is based on the source voltage instead of to ground. Various combinations of these approaches can be used as well. During other operations, such as programming, erase-verify and sensing of negative threshold voltages, the source line bias error is not present, so there is no need for a bias or compensation. A forward body bias can also be compensated.Type: GrantFiled: April 24, 2007Date of Patent: October 20, 2009Assignee: SanDisk CorporationInventors: Deepak Chandra Sekar, Nima Mokhlesi, Hao Thai Nguyen, Seungpil Lee, Man Lung Mui
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Patent number: 7583535Abstract: A body bias is applied to a non-volatile storage system to compensate for temperature-dependent variations in threshold voltage, sub-threshold slope, depletion layer width and/or 1/f noise. A desired bias level is set based on a temperature-dependent reference signal. In one approach, a level of the biasing can decrease as temperature increases. The body bias can be applied by applying a voltage to a p-well and n-well of a substrate, applying a voltage to the p-well while grounding the n-well, or grounding the body and applying a voltage to the source and/or drain of a set of non-volatile storage elements. Further, temperature-independent and/or temperature-dependent voltages can be applied to selected and unselected word lines in the non-volatile storage system during program, read or verify operations. The temperature-dependent voltages can vary based on different temperature coefficients.Type: GrantFiled: December 30, 2006Date of Patent: September 1, 2009Assignee: SanDisk CorporationInventors: Deepak Chandra Sekar, Nima Mokhlesi
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Patent number: 7583539Abstract: A non-volatile storage system in which a body bias is applied to a non-volatile storage system to compensate for temperature-dependent variations in threshold voltage, sub-threshold slope, depletion layer width and/or 1/f noise. A desired bias level is set based on a temperature-dependent reference signal. In one approach, a level of the biasing can decrease as temperature increases. The body bias can be applied by applying a voltage to a p-well and n-well of a substrate, applying a voltage to the p-well while grounding the n-well, or grounding the body and applying a voltage to the source and/or drain of a set of non-volatile storage elements. Further, temperature-independent and/or temperature-dependent voltages can be applied to selected and unselected word lines in the non-volatile storage system during program, read or verify operations. The temperature-dependent voltages can vary based on different temperature coefficients.Type: GrantFiled: December 30, 2006Date of Patent: September 1, 2009Assignee: SanDisk CorporationInventors: Deepak Chandra Sekar, Nima Mokhlesi
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Patent number: 7577031Abstract: Variation in programming efficacy due to variation in time constants along a word line that spans across a memory plane is compensated by adjusting the bit line voltages across the plane to modify the programming rates. In this way, the variation in programming efficacy is substantially reduced during programming of a group of memory cells coupled to the word line. This will allow uniform optimization of programming across the group of memory cells and reduce the number of programming pulses required to program the group of memory cells, thereby improving performance. In one embodiment, during programming, the bit lines in a first half of the memory plane closer to a source of word line voltage is set to a first voltage and the bit lines in a second half of the memory plane further from the source of word line voltage is set to a second voltage.Type: GrantFiled: March 29, 2007Date of Patent: August 18, 2009Assignee: Sandisk CorporationInventors: Deepak Chandra Sekar, Man Lung Mui, Nima Mokhlesi
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Publication number: 20090181862Abstract: A protein chip including at least a substrate having a plurality of steps which are regularly arranged on one surface thereof; a plurality of metallic microstructures arranged in the steps; and a lipid vesicle in which an outer surface thereof is modified by a functional group and a protein is present in a lipid bilayer thereof. The metallic microstructures and the lipid vesicle are bound via the functional group to provide the protein on the substrate.Type: ApplicationFiled: January 11, 2008Publication date: July 16, 2009Applicants: Nippon Telegraph and Telephone Corporation, Isis Innovation Limited, Ewert House, Ewert Place, SummertownInventors: Chandra Sekar Ramanujan, Koji Sumitomo, Maurits R.R. de Planque, Hiroki Hibino, John F. Ryan, Keiichi Torimitsu
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Patent number: 7554853Abstract: A non-volatile storage system in which a body bias is applied to compensate for performance variations which are based on the position of a selected word line which is associated with non-volatile storage elements undergoing program, read or verify operations. In one approach, the body bias increases when the selected word line is closer to a drain side of a NAND string than a source side. In another approach, the body bias varies when the selected word line is an end word line. In another approach, first or second body bias levels can be used when the selected word line is in a first or second group of word lines, respectively. The body bias reduces variations in threshold voltage levels and threshold voltage distributions which are based on the selected word line position. Gate-induced drain leakage (GIDL) is also reduced.Type: GrantFiled: December 30, 2006Date of Patent: June 30, 2009Assignee: SanDisk CorporationInventors: Deepak Chandra Sekar, Nima Mokhlesi
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Publication number: 20090161433Abstract: Techniques are presented for dealing with possible source line bias is an error introduced by a non-zero resistance in the ground loop of the read/write circuits of a non-volatile memory. The error is caused by a voltage drop across the resistance of the source path to the chip's ground when current flows. For this purpose, the memory device includes a source potential regulation circuit, including an active circuit element having a first input connected to a reference voltage and having a second input connected as a feedback loop that is connectable to the aggregate node from which the memory cells of a structural block have their current run to ground. A variation includes a non-linear resistive element connectable between the aggregate node and ground.Type: ApplicationFiled: December 20, 2007Publication date: June 25, 2009Inventors: Dana Lee, Nima Mokhlesi, Deepak Chandra Sekar
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Patent number: 7551477Abstract: An array of non-volatile storage elements includes a first group of non-volatile storage elements connected to a selected word line, a second group of non-volatile storage elements connected to the selected word line, a first group of bit lines in communication with the first group of non-volatile storage elements, a second group of bit lines in communication with the second group of non-volatile storage elements, a first set of sense modules located at a first location and connected to the first group of bit lines, and a second set of sense modules located at a second location and connected to the second group of bit lines. The first set of sense modules applies a first bit line voltage based on the bit line distance between the first set of sense modules and the first group of non-volatile storage elements. The second set of sense modules applies a second bit line voltage based on the bit line distance between the second set of sense modules and the second group of non-volatile storage elements.Type: GrantFiled: September 26, 2007Date of Patent: June 23, 2009Assignee: SanDisk CorporationInventors: Nima Mokhlesi, Dengtao Zhao, Man Mui, Hao Nguyen, Seungpil Lee, Deepak Chandra Sekar, Tapan Samaddar
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Patent number: 7532516Abstract: A non-volatile storage device in which current sensing is performed for a non-volatile storage element with a negative threshold voltage. A control gate read voltage is applied to a selected word line of a non-volatile storage element, and source and p-well voltages are applied to a source and a p-well, respectively, associated with the non-volatile storage element. The source and p-well voltages exceed the control gate read voltage so that a positive control gate read voltage can be used. There is no need for a negative charge pump to apply a negative word line voltage even for sensing a negative threshold voltage. A programming condition of the non-volatile storage element is determined by sensing a voltage drop which is tied to a fixed current which flows in a NAND string of the non-volatile storage element.Type: GrantFiled: June 29, 2007Date of Patent: May 12, 2009Assignee: SanDisk CorporationInventors: Hao Thai Nguyen, Seungpil Lee, Man Lung Mui, Shahzad Khalid, Hock So, Prashanti Govindu, Nima Mokhlesi, Deepak Chandra Sekar
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Patent number: 7525843Abstract: A non-volatile storage system in which body bias can be applied to optimize performance. Body bias can be set in an adaptive manner to reduce an error count of an error correcting and/or detecting code when reading data from non-volatile storage elements. Also, a body bias level can be increased as a number of programming cycles increases. Also, body bias levels can be set and applied separately for a chip, plane, block and/or page. A body bias can be applied to a first set of NAND strings for which operations are being performed by controlling a first voltage provided to a source side of the first set of NAND strings and a second voltage provided to a p-well. A source side of a second set of NAND strings for which operations are not being performed is floated or receives a fixed voltage.Type: GrantFiled: December 30, 2006Date of Patent: April 28, 2009Assignee: SanDisk CorporationInventors: Deepak Chandra Sekar, Nima Mokhlesi
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Publication number: 20090097319Abstract: Body bias can be applied to optimize performance in a non-volatile storage system. Body bias can be set in an adaptive manner to reduce an error count of an error correcting and/or detecting code when reading data from non-volatile storage elements. Also, a body bias level can be increased or decreased as a number of programming cycles increases. Also, body bias levels can be set and applied separately for a chip, plane, block and/or page. A body bias can be applied to a first set of NAND strings for which operations are being performed by controlling a first voltage provided to a source side of the first set of NAND strings and a second voltage provided to a p-well. A source side of a second set of NAND strings for which operations are not being performed is floated or receives a fixed voltage.Type: ApplicationFiled: December 16, 2008Publication date: April 16, 2009Inventors: Deepak Chandra Sekar, Nima Mokhlesi
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Publication number: 20090080229Abstract: A pattern that includes trenches of different depths is formed on a substrate using nanoimprint lithography. A subsequent metal deposition forms lines of different thicknesses according to trench depth, from a single metal layer. Vias extending down from lines are also formed from the same layer. Individual bit lines are formed having different thicknesses at different locations.Type: ApplicationFiled: September 26, 2007Publication date: March 26, 2009Inventors: Deepak Chandra Sekar, Nima Mokhlesi