COMPOUND LIGHT-CONTROL PLATE, SURFACE LIGHT SOURCE DEVICE, AND TRANSPARENT IMAGE DISPLAY DEVICE

摘要

Disclosed is a compound light-control plate (1) wherein light entering from a first surface can radiate from a second surface located on the reverse side from said first surface, and which comprises a mutually superimposed first light control plate (10) and second light control plate (20) having a plurality of protrusions (13, 23) that extend in a first direction and that are disposed in parallel in a second direction perpendicular to said first direction formed on the aforementioned second surfaces. The first light control plate and the second light control plate are each light control plates as defined below. The first direction of the second light control plate is perpendicular to the first direction of the aforementioned first light control plate, and the first surface of the second light control plate faces the second surface of the first light control plate. 0.95×Z0(X)=Z(X)=1.05×Z0(X)...(1), however Z0(x) fulfils formula (2).