To provide a light distribution control element constituted to obtain a high transmittance by suppressing a colored adhesive layer from remaining on the light exit side surface of transparent beads.
The hot melt adhesive layer 104 of the light distribution control element comprising a transparent base material 101, the hot melt adhesive layer 104 formed on this transparent base material and microsphere-like transparent beads 105 consisting of one layer embedded in the hot melt adhesive layer is formed by laminating a transparent adhesive layer 102 and the colored adhesive layer 103 in this order on the transparent base material. In addition, the transparent adhesive layer having the softening temp., or melting temp. or melting viscosity higher than that of the colored adhesive layer 103 is formed and is composed of the structure in which the transparent beads 105 come into contact with the surface of the transparent base material 101. A material which is lower in the softening temp., or melting temp. or melting viscosity of the colored adhesive layer contg. coloring materials, such as carbon black lower than that of the transparent adhesive layer, or conductive particulates or magnetic powder is compounded with the colored adhesive layer 103.
TSUMURA MAKOTO
HIYAMA IKUO
MINEMURA TETSUO
