| 摘要 |
The anode sides of respective EL elements E 1 -E 4 constituting icons are connected to a first potential V 1 , the cathode sides of the EL elements E 1 -E 4 are connected to current absorption sides of constant current sources I 1 -I 4 , and current output sides of the constant current sources are connected to a second potential V 2 whose potential is lower than that of the first potential via light emission control switches S 11 -S 14 . Current regulating resistors R 101 -R 104 are connected in parallel corresponding to the respective EL elements E 1 -E 4 , and therefore by appropriately selecting the resistance values of the current regulating resistors R 101 -R 104 , light emission intensities of the respective EL elements E 1 -E 4 constituting icons can be regulated appropriately. During an all extinction period during which the respective EL elements E 1 -E 4 are all extinguished, an analog switch S 201 is turned off, and an analog switch S 202 is turned on. Thus, the anode sides of all EL elements E 1 -E 4 become ground potential, and a reverse bias voltage is applied to all EL elements E 1 -E 4 . By periodic applying of this reverse bias voltage, the light emission lifetimes of the EL elements E 1 -E 4 can be prolonged.
|
