Patents by Inventor Joo Chung

Joo Chung 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).

  • Publication number: 20060222993
    Abstract: Particles, preferably toner particles comprised of at least binder and colorant, are described that include a doped conductive polymer material as a surface additive on the external surface of the particle. The presence of the doped external conductive polymer material enables the particles to retain a substantially uniform charge distribution over the surface of the particles over time, and also enables appropriate control over the triboelectric (tribo) properties of a developer. Also described are developers comprised of such particles in admixture with carrier particles, and methods of making the particles and developers.
    Type: Application
    Filed: March 31, 2005
    Publication date: October 5, 2006
    Applicant: XEROX CORPORATION
    Inventors: Juan Morales-Tirado, Scott Silence, Joo Chung
  • Publication number: 20060177242
    Abstract: Super wire history image defects in an image development system including one or more electrode wires disposed in a gap between a toner donor roll and an imaging member are reduced by providing an initial toner composition in the image development system, the initial toner composition containing at least 30 number % fine particles having a particle size no greater than 5 ?m; and providing replenisher toner into the development system to replenish the toner used to produce images by the image development system; the replenisher toner containing 20 number % or less fine particles having a particle size no greater than 5 ?m.
    Type: Application
    Filed: February 4, 2005
    Publication date: August 10, 2006
    Applicant: XEROX CORPORATION
    Inventors: James Proper, Joo Chung, Juan Morales-Tirado, Scott Silence, Zhaoyi Masucci, Kristen Ladue, Christine Keenan, Kimberly Stoll
  • Publication number: 20060121378
    Abstract: A process for preparing toner compositions using a dry pigment is provided. The process comprises combining a base toner resin composition, a dry pigment, and dispersion agent in a one step process, without the need any pre-processing of the pigments such as by, for example, flushing. The process includes combining the base toner resin, dry pigment and dispersion agent in a processing apparatus such as an extruder. The process may also comprise preparing the toners via an extrusion process utilizing a screw having a configuration designated herein as a Type C screw.
    Type: Application
    Filed: December 3, 2004
    Publication date: June 8, 2006
    Inventors: Joo Chung, Scott Silence, Joseph Leonardo
  • Publication number: 20060093941
    Abstract: A toner composition includes a binder, a colorant, and a surface additive package including a polydimethylsiloxane surface treated silica, a surface treated titania, and calcium sterate. The toner composition provides improved triboelectric charging properties.
    Type: Application
    Filed: November 4, 2004
    Publication date: May 4, 2006
    Applicant: XEROX CORPORATION
    Inventors: Scott Silence, Joo Chung, Juan Morales-Tirado
  • Publication number: 20060011895
    Abstract: The present invention provides a Pb free Ag paste composition for a PDP address electrode comprising a) 60 to 90% by weight of an Ag powder; b) 1 to 10% by weight of a Pb free inorganic binder; c) 0.001 to 1% by weight of an inorganic thickener; and d) 5 to 38% by weight of an alkali-soluble, negative photoresist composition for fine conductive powder dispersion. The Pb free Ag paste composition according to the invention i) is environment-friendly by using a Pb free inorganic binder, ii) is suitable for the fabrication of fine electrodes by using the prior electrode formation processes, iii) can apply the formed pattern to low temperature sintering processes of not higher than 600° C., iv) does not use a surfactant and stabilizer and has excellent printing, leveling and sintering performances by using an inorganic thickener and conductive Ag powder, and v) enables sintering to be carried out at a sintering target temperature without binder burning off zone.
    Type: Application
    Filed: June 1, 2005
    Publication date: January 19, 2006
    Inventors: Byung-joo Chung, Chan-seok Park, Seong-mo Park, Sin-hye Paek
  • Publication number: 20050186603
    Abstract: The present invention relates to novel human thrombopoietin (hTPO) derivatives, and to process of preparation thereof. Particularly, sugar chains are introduced into native hTPO by substituting amino acids such as asparagine for amino acids at specific positions in native hTPO, preparing novel hTPO derivatives with high activities enhancing the platelet production in vivo. Therefore, the novel hTPO derivatives of this invention may be useful for the treatment of thrombocytopenia associated with anticancer therapy or the transplantation of bone marrow.
    Type: Application
    Filed: January 26, 2005
    Publication date: August 25, 2005
    Inventors: Joo Chung, Sang Kyu Park, Sang Myoung Ju, Hyea Ahn, Seung Wook Lim, Woo Ik Chang, Seung Kook Park, Yeo Wook Koh, Ji Soo Park
  • Patent number: 6845202
    Abstract: An optical fiber for maximizing residual mechanical stress and an optical fiber grating fabricating method using the optical fiber are provided. The optical fiber includes a core formed of silica, for propagating light, and a cladding formed of boron-doped silica, surrounding the core. Alternatively, the optical fiber includes a core formed of phosphorous-doped silica and a cladding formed of silica, surrounding the core.
    Type: Grant
    Filed: January 30, 2003
    Date of Patent: January 18, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Un-Chul Paek, Young-Joo Chung, Chang-Seok Kim, Yong-Woo Park, Hyun-Soo Park, Kyung-Ho Kwack
  • Patent number: 6839865
    Abstract: A system and method for avoiding a single point of failure in the broadcast of streaming data. The system uses multiple redundant servers steaming the exactly same data to a failover device. The failover device buffers the steams into a primary and secondary data stream and automatically switches from the primary to the secondary data stream if it detects a corruption in the primary data stream. Since the buffered data packets of the two steams are identical and are synchronized, there is not outage for multicast receivers when the primary data source fails since there is a switch to exactly the same data in the next packet of the secondary data stream.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: January 4, 2005
    Assignees: Road Runner, ServiceCo, LLC
    Inventors: Kenneth Gould, Joo Chung, Michael Sun, Frank Huang
  • Publication number: 20030138229
    Abstract: An optical fiber for maximizing residual mechanical stress and an optical fiber grating fabricating method using the optical fiber are provided. The optical fiber includes a core formed of silica, for propagating light, and a cladding formed of boron-doped silica, surrounding the core. Alternatively, the optical fiber includes a core formed of phosphorous-doped silica and a cladding formed of silica, surrounding the core.
    Type: Application
    Filed: January 30, 2003
    Publication date: July 24, 2003
    Inventors: Un-Chul Paek, Young-Joo Chung, Chang-Seok Kim, Yong-Woo Park, Hyun-Soo Park, Kyung-Ho Kwack
  • Patent number: 6568220
    Abstract: An optical fiber for maximizing residual mechanical stress and an optical fiber grating fabricating method using the optical fiber are provided. The optical fiber includes a core formed of silica, for propagating light, and a cladding formed of boron-doped silica, surrounding the core. Alternatively, the optical fiber includes a core formed of phosphorous-doped silica and a cladding formed of silica, surrounding the core.
    Type: Grant
    Filed: March 8, 2000
    Date of Patent: May 27, 2003
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Un-Chul Paek, Young-Joo Chung, Chang-Seok Kim, Yong-Woo Park, Hyun-Soo Park, Kyung-Ho Kwack
  • Publication number: 20020071904
    Abstract: The present invention relates to a method of metal coating for an optical fiber grating with a long period. More specifically, the present invention relates to a method of using silver (Ag) as a coating material for an optical fiber through ascertaining its characteristics after silver is coated on the surface of the optical fiber using a silver mirror reaction.
    Type: Application
    Filed: February 5, 2001
    Publication date: June 13, 2002
    Inventors: Un Chul Paek, Young Joo Chung, Byeong Ha Lee, Yong Gon Seo, Sung Jin Lee
  • Patent number: 6392789
    Abstract: An erbium-doped optical fiber (EDF) and a fabricating method thereof The erbium-doped optical fiber has a core formed by substantially doping silica with erbium and having gratings formed therein at a predetermined period, for propagating light therethrough, and a cladding surrounding the core and having a lower refractive index than the core. Since the erbium-doped optical fiber acts as a gain flattening filter, an erbium-doped fiber amplifier formed out of the erbium-doped optical fiber obviates the need of splicing an erbium-doped optical fiber with a gain flattening filter.
    Type: Grant
    Filed: March 9, 2000
    Date of Patent: May 21, 2002
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Un-Chul Paek, Young-Joo Chung, Chang-Seok Kim, Young-Geun Han, Hyun-Soo Park, Kyung-Ho Kwack
  • Patent number: 6385370
    Abstract: There is provided a device and method for forming optical fiber anti-symmetric long period gratings by microbending. In the optical fiber grating forming device, a laser system emits a CO2 laser beam, a lens focuses the CO2 laser beam on an optical fiber in a predetermined width, an optical fiber support fixes both ends of the optical fiber and imparts tensile strain to the optical fiber, and a controller controls the intensity of the CO2 laser beam, the focusing distance of the lens, and the tensile force applied by the optical fiber support.
    Type: Grant
    Filed: March 13, 2000
    Date of Patent: May 7, 2002
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Un-Chul Paek, Young-Joo Chung, Chang-Seok Kim, Jong-Ho Kim, Hyun-Soo Park, Kyung-Ho Kwack
  • Patent number: 6053013
    Abstract: There are provided an optical fiber rod overcladding apparatus and method, and an optical fiber drawing method. In the preform rod overcladding method, a preform rod is clamped in a top chuck and leveled, and a glass tube is mounted in a bottom chuck and leveled. The preform rod is coaxially inserted into a glass tube. Then, the glass tube is preheated by the furnace and heated by the burner until the glass tube reaches a softening point. The preform rod is completely sealed in the glass tube by sucking air in a clearance between the preform rod and the glass tube by application of a negative vacuum pressure. Thus, a preform is completed.
    Type: Grant
    Filed: March 27, 1998
    Date of Patent: April 25, 2000
    Assignee: SamSung Electroncs Co., Ltd.
    Inventors: Seung-Hun Oh, Ki-Un Namkoong, Man-Seok Seo, Un-Chul Paek, Kyung-Hwan Oh, Ghie-Hugh Song, Mun-Hyun Do, Young-Joo Chung
  • Patent number: 5827572
    Abstract: A zirconia material resistant to low temperature degradation and process for manufacturing thereof includes heat treating zirconia material or zirconia composite material at 1200.degree.-1700.degree. C. in the presence of nitrogen source.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: October 27, 1998
    Assignee: Korea Institute of Science & Technology
    Inventors: Huesup Song, Gyeungho Kim, Doh-Yeon Kim, Tai-Joo Chung