| 摘要 |
PURPOSE:To prevent the fatigue of eyes, by giving a brightness control to both the keyboard illuminating light emitting substance and the display unit in accordance with the change of the ambient illuminance. CONSTITUTION:In case the ambient illuminance is high, the brightness of the display unit 3 is increased via the photo transistor 601, the control part 7, the decoder 8 and the driver 9 each. In this case, the keyboard illuminating light emitting substance 10 does not work. While in case the ambient illuminance is low, the keyboard illuminating switch is changed over to secure an illumination to the button face of the keyboard part 2. At the same time, the brightness of the display unit 3 is controlled so as not to stimulate the eyes through the transistor 601 and part 7 and via the decoder 8 and driver 9 each. |
