Patents by Inventor Toru Ujihara

Toru Ujihara 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: 8841615
    Abstract: An electron microscope which utilizes a polarized electron beam and can obtain a high contrast image of a sample is provided. The microscope includes: a laser; a polarization apparatus that polarizes a laser beam into a circularly polarized laser beam; a semiconductor photocathode that is provided with a strained superlattice semiconductor layer and generates a polarized electron beam when irradiated with the circularly polarized laser beam; a transmission electron microscope that utilizes the polarized electron beam; an electron beam intensity distribution recording apparatus arranged at a face reached by the polarized electron beam that has transmitted through the sample. An electron beam intensity distribution recording apparatus records an intensity distribution before and after the polarization of the electron beam is reversed, and a difference acquisition apparatus calculates a difference therebetween.
    Type: Grant
    Filed: February 22, 2011
    Date of Patent: September 23, 2014
    Assignee: National University Corporation Nagoya University
    Inventors: Nobuo Tanaka, Tsutomu Nakanishi, Yoshikazu Takeda, Hidefumi Asano, Koh Saitoh, Toru Ujihara, Makoto Kuwahara
  • Publication number: 20130009058
    Abstract: An electron microscope which utilizes a polarized electron beam and can obtain a high contrast image of a sample is provided. The microscope includes: a laser; a polarization apparatus that polarizes a laser beam into a circularly polarized laser beam; a semiconductor photocathode that is provided with a strained superlattice semiconductor layer and generates a polarized electron beam when irradiated with the circularly polarized laser beam; a transmission electron microscope that utilizes the polarized electron beam; an electron beam intensity distribution recording apparatus arranged at a face reached by the polarized electron beam that has transmitted through the sample. An electron beam intensity distribution recording apparatus records an intensity distribution before and after the polarization of the electron beam is reversed, and a difference acquisition apparatus calculates a difference therebetween.
    Type: Application
    Filed: February 22, 2011
    Publication date: January 10, 2013
    Applicant: NATIONAL UNIVERSITY CORPORATION NAGOYA UNIVERSITY
    Inventors: Nobuo Tanaka, Tsutomu Nakanishi, Yoshikazu Takeda, Hidefumi Asano, Koh Saitoh, Toru Ujihara, Makoto Kuwahara
  • Patent number: 8344354
    Abstract: A spin-polarized electron generating device includes a substrate, a buffer layer, a strained superlattice layer formed on the buffer layer, and an intermediate layer formed of a crystal having a lattice constant greater than a lattice constant of a crystal of the buffer layer, the intermediate layer intervening between the substrate and the buffer layer. The buffer layer includes cracks formed in a direction perpendicular to the substrate by tensile strain.
    Type: Grant
    Filed: March 24, 2009
    Date of Patent: January 1, 2013
    Assignee: National University Corporation Nagoya University
    Inventors: Toru Ujihara, Xiuguang Jin, Yoshikazu Takeda, Tsutomu Nakanishi, Naoto Yamamoto, Takashi Saka, Toshihiro Kato
  • Publication number: 20110089397
    Abstract: To provide implement a spin-polarized electron generating device having high spin polarization and high external quantum efficiency while allowing a certain degree of freedom in selecting materials of a substrate, a buffer layer, and a strained superlattice layer. In a spin-polarized electron generating device having a substrate, a buffer layer, and a strained superlattice layer formed on the buffer layer, an intermediate layer formed of a crystal having a lattice constant greater than that of a crystal used to form the buffer layer intervenes between the substrate and the buffer layer. With this arrangement, tensile strain causes cracks to be formed in the buffer layer in a direction perpendicular to the substrate, whereby the buffer layer has mosaic-like appearance. As a result, glide dislocations in an oblique direction do not propagate to the strained superlattice layer to be grown on the buffer layer, thereby improving crystallinity of the strained superlattice layer.
    Type: Application
    Filed: March 24, 2009
    Publication date: April 21, 2011
    Inventors: Toru Ujihara, Xiuguang Jin, Yoshikazu Takeda, Tsutomu Nakanishi, Naoto Yamamoto, Takashi Saka, Toshihiro Kato
  • Publication number: 20050034756
    Abstract: A Si melt is contacted to a main surface of a Si substrate made of metallurgical Si raw material to conduct liquid phase epitaxy within a temperature range around Si melting point and to form a Si crystal thin film on the main surface of the Si substrate.
    Type: Application
    Filed: June 4, 2004
    Publication date: February 17, 2005
    Applicant: TOHOKU UNIVERSITY
    Inventors: Kazuo Nakajima, Noritaka Usami, Toru Ujihara, Kozo Fujiwara