| 摘要 |
PROBLEM TO BE SOLVED: To provide a key input device or the like capable of detecting many key switches with a small number of ports. SOLUTION: The key input device 1 comprises a key matrix part 2 and a key scan part 3. The key matrix part 2 comprises a first group of wiring C0-C3, a first group of key switches with one end pulled down to the wiring C0-C3 and the other end pulled down, a second group of wiring R1-R3 extended from one end of the three key switches of the first key switches in a predetermined direction, and a second group of key switches arranged on an intersection of the wiring C0-C3 and the wiring R1-R3. The key scan part 3 outputs a high level signal with the one wiring of the wiring C0-C3 as a wiring of a scan object, and then, receives input of a signal on the wiring C0-C3, and detects a status of the key switch connected to the wiring as the scan object out of the first and second groups of the key switches. COPYRIGHT: (C)2007,JPO&INPIT
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