Patents by Inventor Junkou Takagi

Junkou Takagi 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).

  • Spatial filter used in a reduction-type projection printing apparatus
    Patent number: 5642183
    Abstract: A spatial filter used in a reduction-type projection printing apparatus includes a central region through which a light beam passes at transmittance of at most a prescribed value, a substantially transparent peripheral region which surrounds the central region, and a phase shifter for producing phase difference of 180.degree. between light beams passing through the central region and the peripheral region.
    Type: Grant
    Filed: August 23, 1994
    Date of Patent: June 24, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takashi Sugihara, Takashi Fukushima, Junkou Takagi
  • Filter for projection photolithographic system
    Patent number: 5396311
    Abstract: A filter for use in a projection photolithographic system comprising:a circular light-impervious part for screening substantially 100% on the pupil of a projection lens the 0th-order diffracted light of a pattern to be projected on a substrate;a ring-like translucent part concentrically contacting the periphery of the circular light-impervious part to transmit on the pupil part of the 0th-order diffracted light and the +1st- or the -1st-order diffracted light of the pattern; anda ring-like light-pervious part concentrically contacting the periphery of the ring-like translucent part to transmit substantially 100% on the pupil the .+-.1st-order diffracted light of the pattern.
    Type: Grant
    Filed: September 10, 1993
    Date of Patent: March 7, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takashi Fukushima, Takashi Sugihara, Junkou Takagi