| 摘要 |
PROBLEM TO BE SOLVED: To provide a luminous rivet for promoting visibility while compacting size thereof. SOLUTION: Sin (r)/sin (i) is the refractive index of light of a cover 4, αis the tilting angle to the road of the cover 4, γ is the installation angle to the road of the axial center of LED 3 and 90 deg.-γ is β, and in the case an outgoing angle of light to the outside to the road by LED 3 is set as x, α and βare set so as to satisfy γ+α+x=90 deg. and β-α=i. |
