Patents by Inventor Ka Ram Han

Ka Ram Han 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: 20250146180
    Abstract: Disclosed is a post-treatment method of a piezoelectric oxide single crystal substrate for suppressing pyroelectric properties of the substrate, and a method for manufacturing a lithium tantalate single crystal substrate using the same. According to one aspect of the present disclosure, there is provided a post-treatment method of a piezoelectric oxide single crystal substrate, the method including: loading at least one reducing agent and the single crystal substrate into a treatment device; and performing reduction treatment by heat treating the substrate while maintaining the inside of the treatment device in a preset environment, wherein the preset environment means that heat treatment is performed at a temperature of 200° C. to 400° C. under normal pressure.
    Type: Application
    Filed: October 16, 2024
    Publication date: May 8, 2025
    Applicant: Korea Photonics Technology Institute
    Inventors: Seon Hoon KIM, Ju Hyeon CHOI, Doo Gun KIM, Jeong Hwan IN, Ka Ram HAN, So Young KIM, Won Bae SOHN, June Hyuk KANG, Jehwan HWANG
  • Patent number: 10305827
    Abstract: Provided is a technique for transmitting and receiving a chat message through a message server. A user transmits and receives a chat message to and from a friend of a first type and receives a chat message from a friend of a second type, and receives various chat messages from a company supporting the friend of the second type.
    Type: Grant
    Filed: October 30, 2017
    Date of Patent: May 28, 2019
    Assignee: Kakao Corp.
    Inventors: Seung Hwan Van, Ka Ram Han, Yong Hyun Kim, Sung Hwan Chang
  • Publication number: 20180063043
    Abstract: Provided is a technique for transmitting and receiving a chat message through a message server. A user transmits and receives a chat message to and from a friend of a first type and receives a chat message from a friend of a second type, and receives various chat messages from a company supporting the friend of the second type.
    Type: Application
    Filed: October 30, 2017
    Publication date: March 1, 2018
    Inventors: Seung Hwan VAN, Ka Ram HAN, Yong Hyun KIM, Sung Hwan CHANG
  • Patent number: 9807038
    Abstract: Provided is a technique for transmitting and receiving a chat message through a message server. A user may transmit and receive a chat message to and from a friend of a first type and may receive a chat message from a friend of a second type, and receive various chat messages from a company supporting the friend of the second type.
    Type: Grant
    Filed: October 11, 2012
    Date of Patent: October 31, 2017
    Assignee: Kakao Corporation
    Inventors: Seung Hwan Van, Ka Ram Han, Yong Hyun Kim, Sung Hwan Chang
  • Patent number: 9490403
    Abstract: Disclosed are a color converting element and a method for manufacturing the color converting element. The disclosed color converting element includes: first wavelength conversion cells spaced apart from one another; and second wavelength conversion cells arranged among the first wavelength conversion cells. The first and second wavelength conversion cells are made of a material containing glass. The color converting element of the disclosed technology is configured in that color converting cells having different color converting characteristics are periodically arranged, when the color converting element is applied to a color converting glass material which may improve thermal and chemical durability of white LEDs, thus minimizing the degradation of efficiency or luminance caused by an interaction between color converting phosphors or active ions and allowing for ease of adjustment of color rendering index.
    Type: Grant
    Filed: March 23, 2015
    Date of Patent: November 8, 2016
    Inventors: Woon Jin Chung, Ka Ram Han, Yi Kwon Lee
  • Publication number: 20150194579
    Abstract: Disclosed are a color converting element and a method for manufacturing the color converting element. The disclosed color converting element includes: first wavelength conversion cells spaced apart from one another; and second wavelength conversion cells arranged among the first wavelength conversion cells. The first and second wavelength conversion cells are made of a material containing glass. The color converting element of the disclosed technology is configured in that color converting cells having different color converting characteristics are periodically arranged, when the color converting element is applied to a color converting glass material which may improve thermal and chemical durability of white LEDs, thus minimizing the degradation of efficiency or luminance caused by an interaction between color converting phosphors or active ions and allowing for ease of adjustment of color rendering index.
    Type: Application
    Filed: March 23, 2015
    Publication date: July 9, 2015
    Inventors: Woon Jin Chung, Ka Ram Han, Yi Kwon Lee
  • Publication number: 20140173003
    Abstract: Provided is a technique for transmitting and receiving a chat message through a message server. A user may transmit and receive a chat message to and from a friend of a first type and may receive a chat message from a friend of a second type, and receive various chat messages from a company supporting the friend of the second type.
    Type: Application
    Filed: October 11, 2012
    Publication date: June 19, 2014
    Applicant: KAKAO CORP.
    Inventors: Seung Hwan Van, Ka Ram Han, Yong Hyun Kim, Sung Hwan Chang