Browse Prior Art Database

Keyboard Metal Plate Design for ElectroMagnetic Interference Noise Suppression

IP.com Disclosure Number: IPCOM000115953D
Original Publication Date: 1995-Jul-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Fujio, S: AUTHOR [+4]

Abstract

Disclosed is a mechanical design which suppresses ElectroMagnetic Interference (EMI) noise from portable type Personal Computer (PC). Keyboard of the computers wears a metal plate on its back for keyboard reinforcement against typing pressure. The point of this invention is metal plate design for the best use of EMI noise suppression.

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Keyboard Metal Plate Design for ElectroMagnetic Interference Noise
Suppression

      Disclosed is a mechanical design which suppresses
ElectroMagnetic Interference (EMI) noise from portable type Personal
Computer (PC).  Keyboard of the computers wears a metal plate on its
back for keyboard reinforcement against typing pressure.  The point
of this invention is metal plate design for the best use of EMI noise
suppression.

      Figs. 1-1 and 1-2 show the conventional design of the metal
plate.  The plate is designed only for reinforcement of the keyboard
where EMI noise suppression effect is not expected.

      The new design denoted in Figs. 2-1 and 2-2 show the metal
plate extends up to the very edges of the keyboard and the edges of
the plate are folded so that it produces EMI noise suppression
effect, working in consonance with conductive outer shell (1), (2).

      For the most effectiveness of the noise suppression, the hems
of the metal plate and conductive outer shell should have contact by
surface.  If it is mechanically impossible, edges of the plate should
be very close to the conductive outer shell to gain high frequency
conductivity.

      The design is not limited only at the left and/or right edge(s)
of the metal plate, but is applicable to the whole surface of the
metal plate to match outer conductive shell form.