Patents by Inventor Cheon-Il Eom

Cheon-Il Eom 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).

  • Method for absolutely measuring the diffraction grating spacing and apparatus thereof
    Patent number: 5973786
    Abstract: A method of absolutely measuring the diffraction grating spacing and apparatus thereof, which solves the disadvantages of conventional techniques for measuring the diffraction grating spacing, and provides a method utilizing a new laser diffractometer capable of transferring the meter standard to the nanometer region. The invention comprises a first method which utilizes a wavelength stable laser for generating a stable laser beam of wavelength .lambda., 0th and 1st order diffracted beams diffracted at the diffraction grating, and a precision rotary encoder; and a second method utilizing two wave lengths .lambda..sub.1, .lambda..sub.2 of the wavelength stable laser, 0th and 1st order diffracted beams, and a precision rotary encoder.
    Type: Grant
    Filed: January 7, 1998
    Date of Patent: October 26, 1999
    Assignee: Korea Research Institute of Standards and Science
    Inventors: Tai-Hyun Yoon, Cheon-Il Eom, Myung-Sai Chung