| 摘要 |
A mobile terminal device which is provided with a plurality of keys comprises a touch detector; a key specification unit configured to specify a key touched by the user as an effective contact key, when the user touching a key is detected; and a screen changing unit configured to change a screen related to a function which is assigned to the effective contact key specified by the key specification unit, wherein the touch detector detects the user touching a plurality of keys, and the key specification unit specifies the key touched by the user as the effective contact key, on the bases of key specification criteria set according to the arrangement of the keys. An upper position specification unit is configured to specify an upper representative position which is a single position set according to positions of keys touched in an upper row; and a lower position specification unit is configured to specify a lower representative position which is a single position set according to positions of a plurality of lower contact keys, the lower contact keys are the plurality of keys touched by the user arranged in the row lower than the uppermost row. The key specification unit specifies one of the upper contact keys as the effective contact key according to a positional relationship in the right-left direction between the upper representative position and the lower representative position. |
