Patent ID: 11874632
Assignee: BLANCPAIN SA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 21:
22. The optical device according to claim 1, wherein a representation of the Moon is transferred to one of the upper or lower faces of the transparent support, the optical device also comprising drive means which, intended to be moved by the horological movement, drive the shutter, the shutter and the substrate having display contrasts which are inverted relative to each other, the shutter being displaced from the initial position to the final position for a duration of a lunar cycle, so as to reveal day after day to an observer the aspect of the Moon which changes from the new moon to the first quarter moon, then from the first quarter moon to the full moon, then to the last quarter moon and finally to the new moon, the shutter being returned by the drive means from its final position to its initial position at the end of the lunar cycle.