Browse Prior Art Database

Terminal Keys With Anti-Static Pads

IP.com Disclosure Number: IPCOM000036267D
Original Publication Date: 1989-Sep-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Pickover, CA: AUTHOR [+2]

Abstract

Described here is a means of discharging electrostatic voltages each time a keyboard is used. A thin tape is provided on all or selected keys. The tape has two outer conductive vinyl layers and a middle carbon layer. The pad provides a discharge path for static electricity.

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Terminal Keys With Anti-Static Pads

Described here is a means of discharging electrostatic voltages each time a keyboard is used. A thin tape is provided on all or selected keys. The tape has two outer conductive vinyl layers and a middle carbon layer. The pad provides a discharge path for static electricity.

Fig. 1 shows a typical keyboard 1. The circled view shows a typical key 2 on the keyboard. A special tape is firmly attached to the top 3 and the side 4 of the key. A length of the tape is draped underneath the key 5 such that when the key is moved between its highest and lowest position, the tape freely flexes inside of the key to

(Image Omitted)

allow for this movement. The bottom of the tape is mechanically and electrically attached to a grounding frame 6 by solder paste or equivalent.

Fig. 2 shows an exploded view of the tape. The tape is made in long strips which are cut to length during assembly onto the terminal keys. A top 7 and bottom 8 of the conductive vinyl strip are sandwiched around a carbon paste 9. The bottom of the tape is attached to a sticky film on wax paper 10. The wax paper is perforated 11 such that during assembly, the wax paper is removed from the tape in the area of the top and side of the key. The wax paper is left on the portion of the tape that is draped underneath the key.

The vinyl and the carbon paste function as a resistor, which gives several kilo or mega ohms of resistance depending on length. The vinyl serves as a smooth s...