| 摘要 |
PROBLEM TO BE SOLVED: To obtain the display having a bright and good visibility even when the display is viewed from the angle, in which the reflection of external light beams is avoided, by using the reflection plate having a specific reflection light quantity distribution characteristic. SOLUTION: The reflection light plate has a different reflection light quantity distribution characteristic compared with the characteristic of a conventional reflection plate. If the incident angle of the light beams to the reflection plate substrate with respect to a normal direction is -θ degrees (where 0 degree <|θ|90 degrees), a positive reflection angle becomes +θdegrees. If θ' degrees (where 0 degree <|θ'|90 degrees) is the reflection angle and the reflection light quantity becomes a maximum while the degree of the angular dependency of the reflection light quantity is measured, the condition, in which more than four maximum values are obtained in the range of |θ-θ'|>=5 degrees, is satisfied. If the number of the maximum values of the reflection light quantity is less than three, the angle of the visual field, in which a bright and good visibility display is obtained, becomes narrower at the angle where the reflection of external light beams is being avoided. As an example, the surface section of the reflection plate is formed by arranging polygonal pillars adjacent to each other in their ridgeline direction and the cross section has a sawtooth shape in which polygons are connected together. |
