The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 07, 1982
Filed:
Sep. 17, 1980
Ronald J Sears, Middletown, OH (US);
Jack R Gross, Waynesville, OH (US);
NCR Corporation, Dayton, OH (US);
Abstract
A 'membrane'-type keyboard includes a resilient foam layer having an array of holes therein with the layer being sandwiched between first and second flexible membranes having electrical conductors thereon which are arranged to complete a circuit associated with a hole when the first and second membranes are moved toward each other. Embodiments including dome-shaped areas in the first flexible membranes provide for 'tactile feedback' and additional foam layers enhance the operating characteristics of the embodiments. The method generally entails determining the operating parameters of a desired keyboard and simply changing the relative density and/or thicknesses of various layers and flexible membranes in the keyboard to obtain radically variable paremeters, as for example, the location of the 'makepoint' of the switch at various positions between the start and end of 'key travel.'