Crown panto was popular in France from 1940s to 1950s. diadema's front shape is crown panto. Generally speaking, the center of gravity of crown panto tends to be low. However, the frame's design is adjusted to uplift the center so that the frame looks well-balanced.
In order to reduce the burden from the frame to lens, we reconsider the existing metal press process, and develop more suitable design. One of the brand policy is to improve the parts even if they are invisible when we find the improvement necessary as the function of the eyewear.
Diadema means the gold headband which is the origin of crown.