公开(公告)号：US20230236005A1

公开(公告)日：2023-07-27

申请号：US17918950

申请日：2020-04-22

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Masaki NAKAMORI ,  Yukihiro GOTO ,  Hiroyuki OSHIDA

IPC: G01B11/06 ,  G01N21/3581 ,  G01N21/3563

CPC classification number: G01B11/06 ,  G01N21/3581 ,  G01N21/3563

Abstract: An object permittivity measurement apparatus according to the present disclosure includes: a light wave distance measurement device configured to measure reciprocating time t of a light wave with which an object is irradiated and that is reflected and returned from the object, and calculate a distance L to the object using the following equation (1),


L=ct/2   (1)

c: light speed;

an electromagnetic wave phase measurement device configured to measure a rotated phase φ of an electromagnetic wave having a frequency f with which the object is irradiated and that is reflected and returned from the object; and

a permittivity calculation circuit configured to calculate permittivity ε of a foreign material on an object surface using the following equation (2),



φ=4πLf/c+4π(ε)1/2df/c  (2)

d: a thickness of the foreign material on the object surface.

公开(公告)号：US20240369355A1

公开(公告)日：2024-11-07

申请号：US18293408

申请日：2021-08-25

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Masaki NAKAMORI ,  Nazuki HONDA ,  Mitsuyasu YANAGIDA ,  Yukihiro GOTO

IPC: G01B11/30 ,  G01N21/3581 ,  G01N21/952

Abstract: An object of the present disclosure is to enable inspection of an invisible portion covered with a cover or the like with a quantitative index even with backlight. The present disclosure provides a device and a method for determining deterioration of a metal structure having an uneven structure. An image indicating unevenness of a surface of the metal structure measured using a terahertz wave is acquired. The deterioration of the metal structure is determined by analyzing the acquired image.