Patent ID: 9588267
Date: 2017-03-07
CPC Classifications: B32B,E06B,G02B

Claim:
1. An optical element comprising: an optical layer having a flat incident surface on which light is incident; a plurality of beads embedded on one side of the optical layer; a focusing layer formed over a surface of each bead opposite the optical layer; and a wavelength-selective reflective layer disposed on the focusing layer opposite each bead; wherein: θ is the angle of light incident on the first surface or reflected light exiting through the first surface with respect to a normal of the first surface, φ is the angle of a component of the light incident on the first surface or the reflected light projected on the first surface with respect to a specific line in the first surface, and of light incident on the first surface at an incident angle (θ, φ), the optical element selectively directionally reflects the light in at least one specific wavelength range in at least one direction other than a specular reflection direction (−θ, φ+180°) while transmitting light in at least one wavelength range other than the specific wavelength range, and is transparent to light in at least one wavelength range other than the specific wavelength range.