Editing Manual electronic keyboard

'''The manual electronic keyboard''' was the first device that generated an electrical output after the keys were depressed. The keys had a plunger mounted in a [[piezoelectric transducer|piezoelectric or piezoresistive electro-mechanical transducer]] housing. Its patent 3,464,531 was filed on May 16, 1967 and issued on September 2, 1969. <ref>{{ cite patent | country = US | number = 3464531 | status = patent | title = Manual electronic keyboard | pubdate =  | gdate = 1969-9-2 | fdate = 1967-5-16 | pridate =  | inventor = Edward R. Herr | invent1 = George E. Sumrall | invent2 =  | assign1 = Edward M. Fletcher Jr. | assign2 =  | class = }}</ref> <ref> [http://www.google.com/patents/US3464531 Manual electronic keyboard] </ref>

==Description==

'''Manual electronic keyboard'''
*Inventor: Edward R. Herr
*Inventor: George E. Sumrall
*Patent number: 3464531
*Filing date: May 16, 1967
*Issue date: September 2, 1969

==Summary==

The manual electronic keyboard has a plurality of electronic keys arranged throughout the housing. Each key has a plunger mounted in a housing which contains [[piezoelectric transducer|piezoelectric]] or piezoresistive eletro-mechanical transducer from which a pair of terminals connects to. The plunger in each key is designed to be depressed so it bends or compresses the transducer which in turn generates an electrical signal.

==Abstract==

Figure 1 shows an electronic keyboard (10) attached to a [[plate-mounted|mounting plate]] (11) and a plurality of receptacles (12) in which a plug-in sensing key is inserted in each each of the receptacles. 
The key (13) has a pair of contact plugs (14) (15) which makes contact with a pair of conductors (16) that as a result extend each of the receptacles (12) to an amplifier circuit (17).
The amplifiers (17) are connected to a coding circuit (18) such as a diode matrix which has a number of output terminals (19) that produce a coded output on the lines (19), after the amplifiers (17) detect the operation of the key (13) mounted on the flexible cover (20).

==Referenced by Patents==

* {{ cite patent | country = US | number = 5560724 | status =  | title = Keyboard having improved keytop | pubdate =  | gdate = 1996-10-1 | fdate = 1995-6-7 | pridate =  | inventor = Seiichi Iwasa | invent1 = Hideyuki Motoyama | invent2 = Makoto Yoshioka | assign1 =  | assign2 =  | class = }}  

* [http://www.google.com/patents/US5560724 Keyboard having improved keytop]

==Images==

<gallery widths=167 heights=250>
File:US3464531.jpeg|Manual electronic keyboard 
</gallery>

==References==
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[[Category:Patents]]