| 摘要 |
PROBLEM TO BE SOLVED: To obtain a backlight with high surface luminance without irregular luminance by forming a rough layer comprising particles between a polymer film and a metal thin film layer so that a specified metal thin film layer can be formed. SOLUTION: A rough layer 50 comprising a layer of particles, and a metal thin film layer 40 are formed on a polymer film 60. In this method, the rough layer 50 comprising particles is formed in such a manner that a metal thin film layer to be formed thereon shows >=10 % ratio of the min. value to the max. value of the luminance in the angle range of the visual field from -15 deg. to +15 deg., and the max. luminance as >=40% of that of a black glass in the angle range of the visual field from -15 deg. to +15 deg.. As for the rough layer 50, a densely packed particle layer which is substantially a single layer is preferably used. Or, the shape of the valley between particles is controlled to reduce the scattered light. The diameter (particle size) of the particles is preferably 1 to 15 μm, and more preferably 3 to 10 μm. |
