| 摘要 |
747 Comb. A retroreflector of improved efficiency is disclosed comprising, in one form, a light-transmitting sheet adapted in use to be disposed in an angled position such that a normal to the sheet is at an angle of about 5.degree. to about 85.degree. from an incident beam of light. The sheet has front and back opposed, substantially parallel faces. The front face is substantially smooth and defines a light-refracting surface. The back face has a plurality of light-reflecting units. Each unit comprises three mutually perpendicular surfaces defining a trihedral angle of a rectangular parallelepiped and positioned with respect to the front face that the body diagonal of the rectangular parallelepiped is within an angle of 15.degree. of incident light refracted by the front face. A multi-sided retroreflective body also is disclosed having at least two retroreflective faces adapted to intercept light. Each reflective face is tilted in the same general direction about a lower portion angularly away from a vertical plane and is angularly related in a horizontal plane with respect to another vertical plane disposed substantially at right angles to the direction of such light. |
