Browse Prior Art Database

Keyboard Mode Contact

IP.com Disclosure Number: IPCOM000089540D
Original Publication Date: 1977-Nov-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Castle, WH: AUTHOR [+3]

Abstract

If the shift keylever 10 is depressed immediately after another character, so quickly that it enters the shift interposer 12 into the balltube 20 as soon as the character interposer is driven out, the time between the transmit contact signal "make" and the "make" of the shift mode contact is at a minimum. If the electronics have not sampled the transmit signal for the character before the shift mode "makes", then sampling after the mode contact ""makes'' will cause the electronics to interpret the keyboard information incorrectly.

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Keyboard Mode Contact

If the shift keylever 10 is depressed immediately after another character, so quickly that it enters the shift interposer 12 into the balltube 20 as soon as the character interposer is driven out, the time between the transmit contact signal "make" and the "make" of the shift mode contact is at a minimum. If the electronics have not sampled the transmit signal for the character before the shift mode "makes", then sampling after the mode contact ""makes'' will cause the electronics to interpret the keyboard information incorrectly.

A similar situation may occur in shifting from upper case to lower case in that the character printed last in upper case could have the wrong "case" information, if the shift mode contact was ""broken'' by releasing the shift keylever before the transmit contacts were sampled.

A solution to this problem is a latch 22 which will mount in the keyboard. Latch 22 will be "latched" by the upper case interposer 12 motion and bail 24 to hold bail 24 in its displaced position and "unlatched" by the lower case interposer 18 motion to pivot the latch out of engagement with the depending leg 26 to allow bail 24 to restore.

This will insure that the shift mode contact will be in the proper condition during the proper cycle portion.

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