| 摘要 |
<p>PURPOSE:To provide an illuminator adjusting automatically brightness in accor dance with the utilizing situation of a display device being in a building and visibility of characters and graphics displayed on a display screen. CONSTITUTION:The power supply 10 of an illuminator 1 sends the ON/OFF information of the power supply to a light control part 3. When the power supply 10 of the illuminator 1 is turned OFF, the light control part 3 controls a light source part 2 so that a light control level becomes 100%. When the power supply 10 of the illuminator 1 is turned ON, the light control part 3 calculates a visibe index V1 with illuminance information 7 from an ambient light receiving part 5 and with a screen brightness information 8 from a display device 4 in a VL calculating part 6 and controls the brightness of the light source part 2 so that the Vl is in a range from 7 to 10.</p> |
