Browse Prior Art Database

Keyboard

IP.com Disclosure Number: IPCOM000074187D
Original Publication Date: 1971-Mar-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Parry, WE: AUTHOR

Abstract

A keyboard has keybuttons 10 each operating a keylever 12 pivoted at 14 to cause spring 16 to enter slot 18 in sliding interposer 20 and move interposer 20 into ball interlock 22. Light from source 24, shining on a phototransistor, is interrupted and operates a solenoid, not shown, to turn bail shaft 28 which operates pull down link 30 to pull down comb 32 and drive interposer 20 out from ball interlock 22 towards encoding card 34. Conductive PVC fingers 36 beneath interposer 20 touch coded contacts on card 34. Continued rotation of shaft 28 causes edge 38 to slide interposer along to wipe fingers 36 on card 34 and to hold interposer 20 from rising under force of return spring 40. Release of bail shaft 28 allows spring 40 to return interposer 20 and spring 16 yields if key 10 is still depressed.

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Keyboard

A keyboard has keybuttons 10 each operating a keylever 12 pivoted at 14 to cause spring 16 to enter slot 18 in sliding interposer 20 and move interposer 20 into ball interlock 22. Light from source 24, shining on a phototransistor, is interrupted and operates a solenoid, not shown, to turn bail shaft 28 which operates pull down link 30 to pull down comb 32 and drive interposer 20 out from ball interlock 22 towards encoding card 34. Conductive PVC fingers 36 beneath interposer 20 touch coded contacts on card 34. Continued rotation of shaft 28 causes edge 38 to slide interposer along to wipe fingers 36 on card 34 and to hold interposer 20 from rising under force of return spring 40. Release of bail shaft 28 allows spring 40 to return interposer 20 and spring 16 yields if key 10 is still depressed. The contacts on card 34 are coded by either connecting or not connecting each contact to an output line or are coded by their presence or absence.

The output lines each go to a silicon controlled rectifier, not shown, to fire the SCR's in a combination determined by which interposer 20 is operated. Current to operate the SCR's flows from the frame, through the selected interposer 20 and the coded contacts on the card 34 which are touched by the fingers of the selected interposer 20. The output is a parallel coded combination of bits. Case shifting is achieved by physically moving card 34 to bring a different set of coded contacts into play. The keyboard can be op...