| 摘要 |
PROBLEM TO BE SOLVED: To prolong the service life of a device, to prolong the operation time of a battery and to reduce the burdens of a user, while performing the lighting control of a lacklight suitable for a using condition by providing a detection means for detecting the kind of a program and the using condition of a telephone set and controlling the backlight by the operation condition. SOLUTION: A detector 8 detects input/output for a portable telephone set 1 through at input/output interface 7. A liquid crystal display device 5 is provided with a backlight 6, so as to display dial contents and a message and a system controller 10 controls the turning on/off of the backlight 6. The kind of an application operation on the portable telephone set 1 and the operating condition of the application are stored in a storage area 9, and the controller 10 judges whether or not a voice communication application is operated from the information and executes a series of backlight control processings. |
