Patent Number: 7,133,029

Title: Keypad

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.

Inventors: Jamieson; Andrew R (Mulgrave, AU), McGregor; David J (Mulgrave, AU)

Assignee: MCOM Solutions Inc.

International Classification: G09G 5/00 (20060101); H04K 1/00 (20060101); H04L 9/00 (20060101)

Expiration Date: 2019-11-07 0:00:00