Patents by Inventor Jeong-Sik Chang

Jeong-Sik Chang 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).

  • Tricyclodecane dimethanol composition and preparation method of the same
    Patent number: 11964932
    Abstract: Provided are a tricyclodecane dimethanol composition, in which a ratio of structural isomers is controlled, and a preparation method thereof.
    Type: Grant
    Filed: May 20, 2022
    Date of Patent: April 23, 2024
    Assignee: SK Chemicals Co., Ltd.
    Inventors: Hee Il Chae, Ju-Sik Kang, Jeong Ho Park, Song Lee, Yu Mi Chang
  • Phosphine precursor for preparing quantum dot and quantum dot prepared therefrom
    Patent number: 11912915
    Abstract: The present invention relates to a phosphine precursor for the preparation of a quantum dot, and a quantum dot prepared therefrom. Using the phosphine precursor for the preparation of a quantum dot of the present invention, a quantum dot with improved luminous efficiency and higher luminous color purity can be provided.
    Type: Grant
    Filed: March 2, 2018
    Date of Patent: February 27, 2024
    Assignee: SK Chemicals Co., Ltd.
    Inventors: Hee Il Chae, Jeong Ho Park, Kyung Sil Yoon, Ju-Sik Kang, Yu Mi Chang, Nam-Choul Yang, Jae Kyun Park, Song Lee
  • Call reservation technique for a subscriber of another exchange utilizing a no. 7 signal
    Patent number: 5933485
    Abstract: A call reservation technique of a first exchange serving a call of an outgoing subscriber and a second exchange serving a call of an incoming subscriber includes: outputting a message requiring a call reservation registration from the first exchange to the second exchange at the time of reserving the call, and in the second exchange, storing call reservation information according to the message requiring the call reservation registration, the second exchange being transferred to a state of the call reservation registration in response to the message requiring the call reservation registration and simultaneously outputting a call reservation registration response message, and in the first exchange, storing the call reservation information according to the call reservation registration response message and the first exchange being transferred to a state of a call reservation; and checking the state of the incoming subscriber in the state of the call reservation registration in the second exchange and then input
    Type: Grant
    Filed: December 4, 1996
    Date of Patent: August 3, 1999
    Assignee: SamSung Electronics Co., Ltd.
    Inventors: Jeong-Sik Chang, Byung-Hae Jung