| 摘要 |
PURPOSE: To obtain a bright and easy-to-see screen immadiately after a back light is turned on by making the adjustment quantity of brightness change in accordance with a measured lighting time. CONSTITUTION: When a back light 2 is turned on to display information to liquid crystal display elements 1, the measuring of the lighting time is started in a lighting time measuring means 23. Since a flourescent tube has not been in a thermal equilibrium state right after the lighting of the back light 2 and is dark, the adjustment quantity of a brightness adjusting means 22 is made to be changed by a brightness control means 24 so that a display part 12 becomes brighter than a set state previously set. Then, since the flourescent tube approaches to the thermal equilibrium state as the lighting time of the back light 2 increases, the adjustment quantity of the brightness adjusting means 22 is made to be changed by the brightness control means 24 so that the display part 12 returns to the set state. Thus, the screen becomes easy-to-see and the operability of a device is improved. |
