Patent ID: 8049646

Claim:
A key input device comprising: a control section configured to receives a key return signal; and a key matrix section having a plurality of keys, said key matrix section comprises: a plurality of signal line groups; and a plurality of key switch groups comprising said plurality of keys, wherein each of said plurality of key switch groups is provided between two or three of said plurality of signal line groups, when an operated key of said plurality of keys is operated, said key return signal is transferred from said key matrix section to said control section through one of signal lines of one of said plurality of signal line groups, said one signal line corresponding to the operated key wherein said key matrix section comprises: first to third signal line groups; and first to third key switch groups, wherein said first signal line group has a plurality of first signal lines which extend in a first direction in said first key switch group and in a second direction orthogonal to said first direction in said second key switch group, wherein said second signal line group has a plurality of second signal lines which extend in the first direction in said second and third key switch groups, and wherein said third signal line group has a plurality of third signal wirings which extend in the second direction in said first key switch group and in the first direction in said second key switch group.