| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce power consumption of a portable terminal device comprising a key sheet including a key operating part to be operated by a user. <P>SOLUTION: Within a range corresponding to keys on a phosphorescent material sheet 2 which emits light by storing incident light and irradiates a key sheet 1, a mesh part 6 is provided which is formed of a plurality of holes. A light emitting diode (LED) 5 irradiates the key sheet 1 with light via the mesh part 6. A control means 8 causes a timer part 9 to clock a time after the LED 5 is turned on and after the lapse of a predetermined time, the lED 5 is turned off. After the LED 5 is turned off, the key sheet 1 is irradiated with light emitted by the phosphorescent material sheet 2. <P>COPYRIGHT: (C)2009,JPO&INPIT |
