Lunar Phase Display Device Cycloidal Trajectory Mechanism

The annular cover is segmented into four ring portions with convex lobes positioned at specific intervals. This segmentation allows the cover to selectively obscure the moon indicator disc at different positions, creating the lunar phase effect without requiring complex internal mechanisms. Each lobe acts as an independent obscuring element that corresponds to a specific phase of the lunar cycle.

The moon indicator disc performs a cycloidal trajectory movement instead of simple rotation, combining rotational and translational motion in two dimensions. This dimensional change allows the disc to be obscured by the convex lobes at specific points in its path, creating the lunar phase display effect while using a simpler, thinner mechanism than traditional rotating discs with painted phases.

The obscuring function is merged into the annular cover structure itself through the addition of convex lobes, rather than requiring a separate obscuring mechanism. The moon indicator disc and the cover work together as an integrated system where the disc's cycloidal trajectory naturally brings it into and out of the lobes' obscuring paths, eliminating the need for additional thickness-consuming components.

By transitioning from simple rotational motion to cycloidal trajectory motion, the system achieves the lunar phase display effect in a more space-efficient manner. The cycloidal path allows the indicator disc to be obscured by the lobes at specific points without requiring the indicator to travel through a thick mechanical assembly, thereby reducing overall device thickness.