Editing Key rollover keyboard (patent 3918051)

{{infobox patent
| image     = [[file:key rollover keyboard patent 3918051.png|frameless]]
| country   = US
| number    = 3918051
| inventor  = Victor M. Bernin
| issued    = 10 June 1974
| reference = {{cite patent|number=US3918051}}
}}

'''Key rollover keyboard''' (patent 3918051) is an ''n''-key rollover type keyboard that comprises a two dimensional switching matrix with a plurality of drive wires and sense wires pulsed and scanned by a drive and multiplexer circuits respectively with a hysteresis feedback loop. Each key switch has a location that depends on the assigned code to the particular key switch. The output of the shift register is compared with the output of the amplifier so that a strobe generated signal is only applied to the depressed key. <ref> {{ cite patent | country = US | number = 3918051 | status = patent | title = Key rollover keyboard | pubdate =  | gdate = 25 January 1975 | fdate = 10 June 1974 | pridate =  | inventor = Victor M. Bernin | invent1 =  | invent2 =  | assign1 =  | assign2 =  | class = }} </ref>

==Description==

'''Key rollover keyboard'''

* Inventor: Victor M. Bernin
* Patent number: 3918051
* Filing date: 10 June 1974
* Issue date: 25 January 1975

==Referenced by==

* {{ cite patent | country = US | number = 3978474 | status = patent | title = Keyboard with ''n''-key lockout and two key rollover protection | pubdate =  | gdate = 31 August 1976 | fdate = 15 July 1975 | pridate =  | inventor = Keith Allen Engstrom | invent1 =  | invent2 =  | assign1 = Illinois Tool Works Inc. | assign2 =  | class = }}
* {{ cite patent | country = US | number = 4024534 | status = patent | title = Keyboard encoding with repeat key pause | pubdate =  | gdate = 17 May 1977 | fdate = 24 November 1975 | pridate =  | inventor = Wilbur E. DuVall | invent1 =  | invent2 =  | assign1 = Xerox Corporation | assign2 =  | class = }}
* {{ cite patent | country = US | number = 4037225 | status = patent | title = Keyboard encoding system with electronic hysteresis | pubdate =  | gdate = 19 July 1977 | fdate = 25 November 1975 | pridate =  | inventor = Wilbur E. DuVall | invent1 =  | invent2 =  | assign1 = Xerox Corporation | assign2 =  | class = }}
* {{ cite patent | country = US | number = 4110748 | status = patent | title = Keyswitch with hysteresis | pubdate =  | gdate = 29 August 1978 | fdate = 6 April 1976 | pridate =  | inventor = Francis C. Marino | invent1 =  | invent2 =  | assign1 = Burroughs Corporation | assign2 =  | class = }}
* {{ cite patent | country = US | number = 4300127 | status = patent | title = Solid state noncontacting keyboard employing a differential transformer element | pubdate =  | gdate = 10 November 1981 | fdate = 27 September 1978 | pridate =  | inventor = Victor M. Bernin | invent1 =  | invent2 =  | assign1 =  | assign2 =  | class = }}
* {{ cite patent | country = US | number = 4390866 | status = patent | title = Keyboard with electronic hysteresis | pubdate =  | gdate = 28 June 1983 | fdate = 19 February 1981 | pridate =  | inventor = Keith A. Engstrom | invent1 =  | invent2 =  | assign1 = Illinois Tool Works Inc. | assign2 =  | class = }}
* {{ cite patent | country = US | number = 4494109 | status = patent | title = Noncontacting keyboard employing a transformer element | pubdate =  | gdate = 15 January 1985 | fdate = 28 January 1981 | pridate =  | inventor = Victor M. Bernin | invent1 =  | invent2 =  | assign1 =  | assign2 =  | class = }}
* {{ cite patent | country = US | number = 4538146 | status = patent | title = Integrated circuit output pins used for input signals | pubdate =  | gdate = 27 August 1985 | fdate = 17 September 1982 | pridate =  | inventor = Dennis E. Morris | invent1 =  | invent2 =  | assign1 = National Semiconductor Corporation | assign2 =  | class = }}
* {{ cite patent | country = US | number = 4581603 | status = patent | title = Switch matrix key closure validation device and method | pubdate =  | gdate = 8 April 1986 | fdate = 11 March 1983 | pridate =  | inventor = William E. Ingold | invent1 = Dominic J. Daninger | invent2 =  | assign1 = The Maxi-Switch Company | assign2 =  | class = }}
* {{ cite patent | country = US | number = 4794601 | status = patent | title = Keyboard data entry system with hysteresis | pubdate =  | gdate = 3 November 1987 | fdate = 27 June 1985 | pridate =  | inventor = Keith A. Engstrom | invent1 =  | invent2 =  | assign1 = Illinois Tool Works, Inc. | assign2 =  | class = }}
* {{ cite patent | country = US | number = 4706068 | status = patent | title = Four wire keyboard interface | pubdate =  | gdate = 20 September 1988 | fdate = 30 January 1985 | pridate =  | inventor = Martin F. Eberhard | invent1 =  | invent2 =  | assign1 =  [[Wyse|Wyse Technology, Inc]] | assign2 =  | class = }}
* {{ cite patent | country = US | number = 4772874 | status = patent | title = Keyboard apparatus | pubdate =  | gdate = 20 September 1988 | fdate = 7 December 1987 | pridate =  | inventor = Hiroshi Hasegawa | invent1 =  | invent2 =  | assign1 = [[Topre Corporation]] | assign2 =  | class = }}

==Images==

<gallery widths=250 heights=167>
File:key rollover keyboard patent 3918051.png
</gallery>

==References==
<references/>

[[Category:Patents]]