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.

Date of Patent:
Feb. 22, 1983

Filed:

Jun. 09, 1980
Applicant:
Inventors:

Robert C Miller, Braintree, MA (US);

David B O'Keefe, Westford, MA (US);

Assignee:
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K / ; H03K / ;
U.S. Cl.
CPC ...
3072 / ; 307520 ; 307542 ; 3403 / ;
Abstract

A strobe generator in a data entry input device is responsive to an input strobe signal from a keyboard system to generate a strobe signal which is not affected by electrical noise produced by electrostatically or electromagnetically induced signals in the signal lines running between the keyboard system and the data entry device input logic. An accurate output strobe signal is generated by utilizing a retriggerable logic circuit to filter out noise signals of a duration shorter than a predetermined period. The predetermined period is chosen to be less than the minimum duration of a valid input strobe signal and greater than the duration of active noise signals. The strobe generator retains the output strobe signal in the active state by use of a flip-flop until the strobe generator receives a reset signal acknowledging that the output strobe signal has been sampled by the data entry device input logic. Once set, the flip-flop will remain set and its corresponding output strobe signal remain active until reset, even if subsequent input strobe signals of less than or greater than the predetermined period are received.


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