| 摘要 |
PROBLEM TO BE SOLVED: To provide a display device with an excellent man-machine interface for allowing a user to easily know a hierarchy or system to which a displayed screen is belonging and the relation with the other screens without reducing a display area by fully contriving the display of plural screens constituting a directory structure. SOLUTION: Plural key input screens are mutually related with each other so that a directory structure can be obtained. The directory structure has first - fourth hierarchies, and each key input screen is positioned in any hierarchy. When a transition key in a basic screen 100 belonging to the first hierarchy is pressed, the display screen is switched to any key input screen belonging to the second hierarchy. A display device displays the key input screen by changing a display color according to the hierarchy to which the key input screen to be displayed is belonging. |
