| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a portable terminal device with an operation unit using a phosphorescent material having phosphorescence property, which allows the phosphorescent material to store phosphorescence at appropriate timing when storing phosphorescence by a light source unit. <P>SOLUTION: In a portable terminal device, an open button 8 is a button for opening an operation unit housing 1 and a display unit housing 2 and releasing their folding states, and includes: an electric contact switch 8a to be turned on when a first-stage depression operation of only lightly touching is performed; and a mechanical switch 8b for opening the operation unit housing 1 and the display unit housing 2 and releasing their folding states when a second-stage depression operation of deep pushing-in is performed. A control circuit unit 11 discriminates whether timing is usage start timing for starting the use of a portable telephone or not, based on whether or not the electric contact switch 8a is turned on by the first stage depression operation of the open button 8, and starts to store phosphorescence of a phosphorescent material in a key operation unit 5 by driving a back light 7b of a display unit 7 when the timing is the usage start timing. <P>COPYRIGHT: (C)2012,JPO&INPIT |
