Title:
ELECTROMAGNETIC WAVE SCREENING BREATHING HOLE
Document Type and Number:
Japanese Patent JP2788862
Kind Code:
B2
Abstract:
PURPOSE: To provide an electromagnetic wave screening breathing hole used for an electric dark room and an electromagnetic screening room for screening electromagnetic waves within a wide band from a low frequency to a mm-wave region.
CONSTITUTION: In an electromagnetic wave screening breathing hole, a honeycomb screening material is provided in the entrance of the breathing hole and a pyramid or wedge-shaped electric wave absorbing material is fitted to the inner wall of the breathing hole. In the electric wave absorber, the view up to an exit is closed since the section entire region of the breathing hole is hidden by either absorbing body when viewed from the entrance surface of the breathing hole, and the installation position of the electric wave absorber is shifted in the depth direction of the breathing hole to secure the circulation of air. A length L of the breathing hole for fitting the electric wave absorbing body should be 2-3 wavelengths or longer. With this structure, an improved screening property can be achieved within a wide frequency range from a low frequency region to a mm-wave region.
Inventors:
HATAKEYAMA KENICHI
TOGAWA HITOSHI
TOGAWA HITOSHI
Application Number:
JP33787794A
Publication Date:
August 20, 1998
Filing Date:
December 27, 1994
Export Citation:
Assignee:
NIPPON DENKI KK
TOOKIN KK
TOOKIN KK
International Classes:
F24F7/04; H05K9/00; (IPC1-7): H05K9/00; F24F7/04
Domestic Patent References:
| JP4202981A | ||||
| JP56101697U | ||||
| JP546318Y2 |
Attorney, Agent or Firm:
Soro Koro
Previous Patent: MAGNETIC SEPARATOR AND WIPING BRUSH TO BE USED THEREFOR
Next Patent: AUTOMATICALLY CHANGEABLE RECORDING MEDIUM REPRODUCING DEVICE
Next Patent: AUTOMATICALLY CHANGEABLE RECORDING MEDIUM REPRODUCING DEVICE