Browse Prior Art Database

EMI Noise Reduction Method Using Shielding Meshed Wire

IP.com Disclosure Number: IPCOM000113009D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 64K

Publishing Venue

IBM

Related People

Fukuda, K: AUTHOR [+4]

Abstract

This article describes a method to reduce Electromagnetic Interference (EMI) emission by indirect electrical connection between the display subassembly and the Notebook PC enclosure. The indirect contact is caused by the conductive material (e.g., metal flat tape, metal tube, metal mesh tube or other metal material) wrapped round the display interface cables of Notebook PC. This method is effective in the reduction of EMI radiated/conducted emission and the decrease of the influence caused by electromagnetic energy coupled into sensitive circuits, interconnecting signal lines and power leads in Notebook PC.

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EMI Noise Reduction Method Using Shielding Meshed Wire

      This article describes a method to reduce Electromagnetic
Interference (EMI) emission by indirect electrical connection between
the display subassembly and the Notebook PC enclosure.  The indirect
contact is caused by the conductive material (e.g.,  metal flat tape,
metal tube, metal mesh tube or other metal material) wrapped round
the display interface cables of Notebook PC.  This method is
effective in the reduction of EMI radiated/conducted emission and the
decrease of the influence caused by electromagnetic energy coupled
into sensitive circuits, interconnecting signal lines and power leads
in Notebook PC.

      Fig. 1 shows an appearance of IBM Notebook PC.  It consists of
the flat display module 1 and the system unit 2.  Fig. 2 and Fig. 5
show relation between electromagnetic field strength and frequency
radiated from Notebook Type Personal Computer.  Line 4 in Fig. 2
shows Federal Communication Commission (FCC) class B limit line of
EMI radiated emission level.  Fig. 2 shows the EMI radiated emission
from Notebook Type Personal Computer which has the indirect contact
between the shielding material of the flat display module 1 and the
shielding material of the system unit 2 by using the Hinge made of
conductive material at the Hinge area 3.

      Fig. 3 shows the display interface cable between the flat
display module and the system unit.  It consists of the signal line
5, the power lin...