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US 4,503,294 AGranted
Keyboard switch
AssigneeNippon Mektron, Ltd.
InventorAkihiko Matsumaru
Life of this patent
Estimating the term…
Abstract
A membrane keyboard is presented wherein a series of slits are provided through the switch sheet and disposed above the switch motion cavity whereby the required actuating forces are decreased for switch operational areas of small size relative to those switch operational areas of larger size.
Claims8
A membrane keyboard including:
- first electrical circuit means having a plurality of first switch contacts;
- second electrical circuit means having a plurality of second switch contacts, and defining a switch sheet;
- insulating spacer means between said first and second electrical circuit means, said spacer means having a plurality of openings at locations corresponding to the locations of said first and second switch contacts, said openings defining switch motion cavities and wherein said switch motion cavities define switch operational areas of varying size wherein at least one of said switch operational areas is smaller than said other of said switch operational areas;
- and
- at least one slit through said switch sheet disposed above at least one of said switch motion cavities which defines said smaller switch operational area wherein the force for actuating said smaller switch operational area is reduced.
2 more elements
Dependencies are inferred from the claim text.