Computer graphics processing and selective visual display system – Display peripheral interface input device – Including keyboard
Reexamination Certificate
2006-09-25
2010-06-22
Hjerpe, Richard (Department: 2629)
Computer graphics processing and selective visual display system
Display peripheral interface input device
Including keyboard
Reexamination Certificate
active
07742040
ABSTRACT:
A keypad is disclosed which has a plurality of keys (12) for the input of information. Each key has a first switch (80) and a second switch (90). The first switches (80) are all connected to a common electrical interconnection (120) and the second switches (90) are connected into a matrix electrical interconnection (62, 100). The microprocessor (66) detects a global signal on the common interconnection (120) and supplies scan signals to the matrix interconnection (62, 100) to enable detection of a particular key. The processor (66) may also selectively change the state of lines (62, 100) of the matrix and also maintain particular lines in a predetermined state by open drain ports of the processor to which the lines of the matrix are connected.
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Jamieson Andrew R
McGregor David J
Hjerpe Richard
Sheng Tom V
Sterne Kessler Goldstein & Fox PLLC
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