Patent ID: 8388154

Claim:
A cube-corner retroreflective article comprising a number of cube-corner retroreflective element pairs each formed by a pair of cube-corner retroreflective elements sharing one side, each of the cube-corner retroreflective elements having reflective lateral surfaces including two trapezoidal reflective lateral surfaces and one pentagonal or isosceles-triangular reflective lateral surface, and having a projection shape of a quadrangle when projected onto a common plane, wherein ratios (rHA/rHC and rHB/rHC) between a length (rHC) of a ridge (Hc) shared by the trapezoidal reflective lateral surfaces (HAFC and HBGC) and lengths (rHA and rHB) of other ridges (HA and HB) are in a range of 0.5 to 1.5; ratios (Sc/Sa and Sc/Sb) between areas (Sa and Sb) of the trapezoidal reflective lateral surfaces (HAFC and HBGC) and an area (Sc) of the pentagonal reflective lateral surface (HADEB) or the isosceles-triangular reflective lateral surface (HAB) is in a range of 0.6 to 1.4; and a ratio (rHK/rHC) between the length (rHC) of the ridge (HC) and a length (rHK) of a perpendicular (HK) from an apex (H) of each of the cube-corner retroreflective elements to a shared base (DE) is in a range of 0.55 to 1.8.