| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a display device capable of reducing the power consumption and obtaining a suitable screen luminance to an environmental illuminance in an environment that covers a wide illuminance range, i.e., from low to high illuminance. SOLUTION: This device is provided with a display element 1, which has a reflection plate 25, a light guiding plate 26, which emits the incident light beams from a front surface and the incident light beams from an illuminating light beam taking in end face 26a to the back surface so as to make them incident on the element 1 and takes in the light beams that are reflected by the plate 25 and emitted to the front surface of the element 1 from the back surface and emits the taken in light beams to the front surface, a light source 27 which is arranged and opposed against the face 26a of the plate 26, and an illumination luminance control means 30 which controls the luminance of the illumination light beams emitted by the source 27 in accordance with the environmental illuminance. The reflectivity of the plate 25 and the luminance control condition of the illuminating light beams by the means 30 are set so that the luminance of the screen of the element 1 becomes within the luminance range beforehand set in accordance with the environmental illuminance.</p> |
