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:
Jun. 22, 1999
Filed:
Jan. 15, 1997
Behnam H Ahmadian, Los Gatos, CA (US);
Chips & Technologies, Inc., San Jose, CA (US);
Abstract
A switch array decoding circuit, suitable for use in a keyboard, and method according to the present invention comprises a matrix of row lines and column lines. Switches from the array are connected between intersections of the row lines and column lines. The row lines and column lines are connected to I/O pins leading to one or more components containing the decoder circuitry. The decoder circuitry first simultaneously drives the row lines while sensing the column lines. When a switch closure is detected, the states of all column lines are simultaneously sensed. This operation determines the column position(s) of the one or more switches being closed. The column lines are then simultaneously driven while simultaneously sensing the row lines. This operation determines the row position(s) of the one or more switches being closed. The row and column drive and sense order may be reversed.