Patents by Inventor David Yen

David Yen 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).

  • Patent number: 7910662
    Abstract: The invention discloses improved processes to halogenate polymers. In particular, the invention discloses to improved processes to halogenate polymers made from C4-1012 isoolefins.
    Type: Grant
    Filed: December 28, 2005
    Date of Patent: March 22, 2011
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: David Yen-Lung Chung, Michael Francis McDonald, Robert Norman Webb, Richard Dwight Hembree
  • Publication number: 20100231172
    Abstract: A battery charger for a portable electronic device includes a linear charger to generate a substantially constant current for charging the battery and a switching voltage regulator to convert power supplied by an external adapter to a supply voltage for the linear charger. A feedback circuit controls operation of the switching voltage regulator so that the voltage supplied to the linear charger is substantially equal to the combination of the battery voltage and the drain-to-source voltage of the linear charger. In this way, power dissipation by the linear charger is minimized without requiring the use of a high accuracy current limited adapter.
    Type: Application
    Filed: March 13, 2009
    Publication date: September 16, 2010
    Applicant: ADVANCED ANALOGIC TECHNOLOGIES, INC.
    Inventors: Siamak Bastami, David Yen Wai Wong, Thomas Zoki Li
  • Patent number: 7781547
    Abstract: The invention relates to new polymerization processes using hydrofluorocarbons to produce polymers. In particular, the invention relates to new polymerization processes using turbulent flow reactor systems using diluents including one or more hydrofluorocarbon(s) to produce polymers.
    Type: Grant
    Filed: June 25, 2004
    Date of Patent: August 24, 2010
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Yuan-Ju (Ray) Chen, Michael Francis McDonald, Timothy Daniel Shaffer, David Yen-Lung Chung, Robert Norman Webb
  • Publication number: 20100165704
    Abstract: A memory cell is disclosed, including a write access transistor coupled between a storage node and a write bit line, and active during a write cycle responsive to a voltage on a write word line; a read access transistor coupled between a read word line and a read bit line, and active during a read cycle responsive to a voltage at the storage node; and a storage capacitor coupled between the read word line and the storage node. Methods for operating the memory cell are also disclosed.
    Type: Application
    Filed: December 30, 2008
    Publication date: July 1, 2010
    Inventors: Cheng-Hsu Wu, David Yen, Tsai-Hsin Lai
  • Patent number: 7723447
    Abstract: The invention provides for a process to produce polymers utilizing a hydrofluorocarbon diluent.
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: May 25, 2010
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Scott Thomas Milner, Michael Gerard Matturro, Timothy Daniel Shaffer, Robert Norman Webb, David Yen-Lung Chung, Michael Francis McDonald
  • Patent number: 7659355
    Abstract: The invention relates to novel air barriers made from elastomeric compositions. In particular, the invention relates to novel air barriers such as innerliners, air sleeves, and innertubes made from novel C4 to C7 isoolefin based polymers with new sequence distributions or that are substantially free of long chain branching.
    Type: Grant
    Filed: June 13, 2005
    Date of Patent: February 9, 2010
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Walter Harvey Waddell, David Yen-Lung Chung
  • Patent number: 7585914
    Abstract: The present invention provides a thermoplastic composition which may be unvulcanized or vulcanized. The thermoplastic composition can be a blend of a thermoplastic engineering resin, a halogenated terpolymer of a C4 to C7 isomonoolefin, a para-alkylstyrene, and a multiolefin. The engineering resin can be a polyamide, such as nylon 6/66 copolymers for example. The isomonoolefin can be an isobutylene for example. The multiolefin can be a C4 to C14 diene, such as isoprene for example.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: September 8, 2009
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Andy Haishung Tsou, David Yen-Lung Chung
  • Patent number: 7582715
    Abstract: The invention relates to new polymerization processes including diluents including hydrofluorocarbons and their use to produce novel polymers substantially free of long chain branching. In particular, the invention relates to copolymers of an isoolefin, preferably isobutylene, and a multiolefin, preferably a conjugated diene, more preferably isoprene, substantially free of long chain branching.
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: September 1, 2009
    Assignee: Exxonmobil Chemical Patents Inc.
    Inventors: Scott Thomas Milner, Timothy Daniel Shaffer, David Yen-Lung Chung
  • Patent number: 7576525
    Abstract: Charge storage devices (e.g., batteries or supercapacitors) need to be charged from time to time. In an apparatus, to protect a charge storage device as well as the supply used to charge it, the apparatus typically includes power loop control circuitry. One approach to implementing the power loop control employs a temperature sensor in combination with soft start circuitry in order to protect the circuitry from a rapidly increasing temperature when charge current increases. The soft start circuitry allows for controlled step-wise increase and regulation of the current. The approach preferably allows for selecting the number and resolution of such incremental steps. Various embodiments of the invention include devices and methods for controlling power and may take into account temperature in step-wise regulation of the charge current.
    Type: Grant
    Filed: May 16, 2007
    Date of Patent: August 18, 2009
    Assignee: Advanced Analogic Technologies, Inc.
    Inventors: John So, David Yen Wai Wong
  • Publication number: 20090102493
    Abstract: An integrated circuit product includes: 1) a package, 2) a semiconductor die mounted within the package, 3) a first terminal and a second terminal for connecting the integrated circuit product to an external circuit, 4) one or more bond wires for transferring a current received at the first terminal to the second terminal; and 5) a circuit included in the semiconductor die that measures a voltage difference attributable to the resistance of the bond wires to measure the magnitude of the current passing through the first terminal.
    Type: Application
    Filed: October 18, 2007
    Publication date: April 23, 2009
    Applicant: ADVANCED ANALOGIC TECHNOLOGIES, INC.
    Inventors: Donald Ray Disney, John S.K. So, David Yen Wai Wong
  • Patent number: 7491773
    Abstract: The invention relates to new polymerization processes including diluents including hydrofluorocarbons and their use to produce novel halogenated polymers with new sequence distributions. In particular, the invention relates to halogenated copolymers of an isoolefin, preferably isobutylene, and a multiolefin, preferably a conjugated diene, more preferably isoprene, with new sequence distributions.
    Type: Grant
    Filed: December 10, 2004
    Date of Patent: February 17, 2009
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Timothy Daniel Shaffer, David Yen-Lung Chung
  • Patent number: 7491764
    Abstract: The present invention includes blends of a halogenated elastomer such as a butyl rubber or an interpolymer of, on one embodiment, a C4 to C7 isomonoolefin, a para-methylstyrene and a para-(halomethylstyrene), the interpolymer having been pre-mixed with an exfoliating compound and clay, the entire blend forming a nanocomposite in one embodiment. The clay may or may not have undergone an additional exfoliating treatment prior to blending with the halogenated elastomer. The interpolymer/clay mixture forms a distinct phase in the nanocomposite blend of the invention. The blend of the invention has improved air barrier properties and is suitable as an air barrier.
    Type: Grant
    Filed: May 29, 2002
    Date of Patent: February 17, 2009
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Anthony Jay Dias, Andy Haishung Tsou, David Yen-Lung Chung, Weiqing Weng
  • Patent number: 7485677
    Abstract: The present invention is a blend of an halogenated elastomer and a clay, desirably an exfoliated clay, to form a nanocomposite suitable for an air barrier. In one embodiment, the halogenated elastomer is a polymer comprising C4 to C7 isoolefin derived units, a para-methylstyrene derived units, and para-(halomethylstyrene) derived units. In another embodiment, the halogenated elastomer is a butyl-type rubber. The clay may or may not have an additional exfoliating treatment present prior to blending with the interpolymer. The interpolymer/clay mixture forms a distinct phase in the nanocomposite blend of the invention. The blend of the invention has improved air barrier properties and is suitable as an innerliner or innertube.
    Type: Grant
    Filed: May 29, 2002
    Date of Patent: February 3, 2009
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Anthony Jay Dias, Andy Haishung Tsou, David Yen-Lung Chung, Weiqing Weng, Caiguo Gong
  • Publication number: 20080319119
    Abstract: The invention provides for processes to produce elastomeric compositions, the processes including contacting at least one elastomer with a processing aid, wherein the processing aid includes the reaction product of at least one functionalized polymer having at least one anhydride group contacted with at least one polyamine, wherein the at least one polyamine includes at least one primary amine. The invention also provides for articles such as innerliners for tires produced from the aforementioned elastomeric compositions.
    Type: Application
    Filed: December 16, 2005
    Publication date: December 25, 2008
    Applicant: EXXONMOBIL CHEMICAL PATENTS INC.
    Inventors: Walter Harvey Waddell, David Yen-Lung Chung, Robert Christopher Napier, Donald Sheley Tracey
  • Publication number: 20080290049
    Abstract: The invention relates to methods for separating slurry components. In particular, the invention relates to the concentration of polymer particles in a slurry from the polymerization of C4-C7 isoolefins.
    Type: Application
    Filed: June 23, 2004
    Publication date: November 27, 2008
    Inventors: Timothy Daniel Shaffer, Scott Thomas Milner, David Yen-Lung Chung, Michael Francis McDonald, Robert Norman Webb, Pamela Jean Wright
  • Publication number: 20080293892
    Abstract: The invention discloses improved processes to halogenate polymers. In particular, the invention discloses to improved processes to halogenate polymers made from C4-1012 isoolefins.
    Type: Application
    Filed: December 28, 2005
    Publication date: November 27, 2008
    Inventors: David Yen-Lung Chung, Michael Francis McDonald, Robert Norman Webb, Richard Dwight Hembree
  • Publication number: 20080281021
    Abstract: The invention provides for processes to produce elastomeric compositions, the processes including contacting at least one elastomer with a processing aid, wherein the processing aid comprises at least one functionalized polymer having at least one anhydride group. The invention also provides for articles such as innerliners for tires produced from the aforementioned elastomeric compositions.
    Type: Application
    Filed: December 16, 2005
    Publication date: November 13, 2008
    Applicant: EXXONMOBIL CHEMICAL PATNES INC.
    Inventors: Walter Harvey Waddell, David Yen-Lung Chung, Robert Christopher Napier, Donald Sheley Tracey, Dirk Frans Rouckhout
  • Publication number: 20080262130
    Abstract: The invention provides for processes to produce elastomeric compositions, the processes including contacting at least one elastomer with a processing aid, wherein the processing aid comprises at least one functionalized polymer having at least one halogen group. The invention also provides for articles such as innerliners for tires produced from the aforementioned elastomeric compositions.
    Type: Application
    Filed: December 5, 2005
    Publication date: October 23, 2008
    Inventors: Walter Harvey Waddell, David Yen-Lung Chung, Robert Christopher Napier, Donald Sheley Tracey
  • Publication number: 20080258686
    Abstract: A method for detecting removal of a battery from a battery charger includes 1) incrementing an event counter and resetting an interval counter each time the voltage present at the output node exceeds a predetermined voltage; 2) resetting the event counter each time the interval counter exceeds a predetermined maximum time between events; and 3) asserting a signal indicating the absence of a battery connected between the positive and negative output nodes each time event counter exceeds a predetermined number of events.
    Type: Application
    Filed: April 17, 2007
    Publication date: October 23, 2008
    Applicant: ADVANCED ANALOGIC TECHNOLOGIES, INC.
    Inventors: Thomas Li, John S.K. So, David Yen Wai Wong
  • Patent number: 7425601
    Abstract: The invention relates to new polymerization processes including diluents including hydrofluorocarbons and their use to produce novel polymers with new sequence distributions. In particular, the invention relates to copolymers of an isoolefin, preferably isobutylene, and an alkylstyrene, preferably methylstyrene, even more preferably para-methylstyrene, with new sequence distributions. The copolymer may optionally be halogenated.
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: September 16, 2008
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: David Yen-Lung Chung, Timothy Daniel Shaffer