Patents by Inventor Jung-ik Choi

Jung-ik Choi 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: 9818947
    Abstract: A semiconductive roller to stably generate high-quality images for a long period of time by efficiently inhibiting migration of free epichlorohydrin (ECH) component to a surface of the semiconductive roller includes an elastic layer formed of a semiconductive rubber composition including about 50 to about 70 parts by weight of a base rubber and about 30 to about 50 parts by weight of a hydrin rubber. An extracted amount of the ECH component from the elastic layer is about 2% by volume or less, wherein the extracted amount is determined based on a reduced amount of chlorine (Cl) intensity measured using X-ray fluorescence (XRF) analysis performed before and after extraction of the ECH component from the elastic layer using tetrahydrofuran (THF).
    Type: Grant
    Filed: January 30, 2014
    Date of Patent: November 14, 2017
    Assignee: S-PRINTING SOLUTION CO., LTD.
    Inventors: Kwang-ho Kang, Jae-hyeuk Jeong, Jung-ik Choi
  • Publication number: 20150087488
    Abstract: A semiconductive roller to stably generate high-quality images for a long period of time by efficiently inhibiting migration of free epichlorohydrin (ECH) component to a surface of the semiconductive roller includes an elastic layer formed of a semiconductive rubber composition including about 50 to about 70 parts by weight of a base rubber and about 30 to about 50 parts by weight of a hydrin rubber. An extracted amount of the ECH component from the elastic layer is about 2% by volume or less, wherein the extracted amount is determined based on a reduced amount of chlorine (Cl) intensity measured using X-ray fluorescence (XRF) analysis performed before and after extraction of the ECH component from the elastic layer using tetrahydrofuran (THF).
    Type: Application
    Filed: January 30, 2014
    Publication date: March 26, 2015
    Applicant: Samsung Electronics Co., Ltd
    Inventors: Kwang-ho KANG, Jae-hyeuk JEONG, Jung-ik CHOI
  • Patent number: 8546054
    Abstract: An electrophotographic toner includes a binder resin, a colorant, and a releasing agent, wherein the electrophotographic toner has a complex viscosity (?) of 4e2 Pa·s to 8e3 Pa·s at a temperature range of 120 to 160° C. and an angular velocity range of 1.6 to 10 rad/s, a rate of change of the complex viscosity of 165 to 185 Pa·s/° C. at 1.6 rad/s, and 70 to 80 Pa·s/° C. at 10 rad/s within the temperature range, a stress relaxation of 1.0 e3 to 4.5 e4 Pa at a relaxation time of 0.05 to 0.3 seconds under a temperature range of 120 to 160° C., and a rate of change of the stress relaxation (?G/?T) of 785 to 1000 Pa/° C. at 0.05 seconds and 190 to 215 Pa/° C. at 0.3 seconds within the temperature range above.
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: October 1, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jae-hyeuk Jeong, Duck-hee Lee, Deuck-woo Jang, Jung-ik Choi, Soon-cheol Jeong, Hae-ree Joo
  • Patent number: 8492061
    Abstract: The disclosure provides electrophotographic toner and a method of preparing the same. The toner includes a latex, a colorant, and a releasing agent, wherein the toner has a weight-average molecular weight of about 50,000 to about 80,000; a complex viscosity of about 1×103 to about 5×104 (Pa·s) at a temperature ranging from about 100° C. to about 140° C.; and a storage modulus Pa (dG?) to a loss modulus Pa (dG?) (dG?/dG?) ratio of about 1.10 to about 1.25.
    Type: Grant
    Filed: November 4, 2009
    Date of Patent: July 23, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jae-Hyeuk Jeong, Kyeong Pang, Jung-Ik Choi, Soon-Cheol Jeong, Hong-Chul Shin
  • Publication number: 20100167194
    Abstract: The disclosure provides electrophotographic toner and a method of preparing the same. The toner includes a latex, a colorant, and a releasing agent, wherein the toner has a weight-average molecular weight of about 50,000 to about 80,000; a complex viscosity of about 1×103 to about 5×104 (Pa·s) at a temperature ranging from about 100° C. to about 140° C.; and a storage modulus Pa (dG?) to a loss modulus Pa (dG?) (dG?/dG?) ratio of about 1.10 to about 1.25.
    Type: Application
    Filed: November 4, 2009
    Publication date: July 1, 2010
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Jae-Hyeuk JEONG, Kyeong Pang, Jung-Ik Choi, Soon-Cheol Jeong, Hong-Chul Shin
  • Publication number: 20090214965
    Abstract: An electrophotographic toner includes a binder resin, a colorant, and a releasing agent, wherein the electrophotographic toner has a complex viscosity (?) of 4e2 Pa·s to 8e3 Pa·s at a temperature range of 120 to 160° C. and an angular velocity range of 1.6 to 10 rad/s, a rate of change of the complex viscosity of 165 to 185 Pa·s/° C. at 1.6 rad/s, and 70 to 80 Pa·s/° C. at 10 rad/s within the temperature range, a stress relaxation of 1.0 e3 to 4.5 e4 Pa at a relaxation time of 0.05 to 0.3 seconds under a temperature range of 120 to 160° C., and a rate of change of the stress relaxation (?G/?T) of 785 to 1000 Pa/° C. at 0.05 seconds and 190 to 215 Pa/° C. at 0.3 seconds within the temperature range above.
    Type: Application
    Filed: September 29, 2008
    Publication date: August 27, 2009
    Inventors: Jae-hyeuk Jeong, Duck-hee Lee, Deuck-woo Jang, Jung-ik Choi, Soon-cheol Jeong, Hae-ree Joo