Moon Phase Indicator Mechanism with Occultation Discs

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Solution Overview

Problem

Traditional moon phase indicating mechanisms for mechanical watches do not accurately represent the real appearance of the illuminated surface of the moon throughout its phases, particularly during waxing and waning phases, as they only depict a concave shape, failing to account for the varying geometric constellations between the Earth, Moon, and Sun.

Innovation Solution

A mechanism featuring at least one occultation disc housed between the moon disc and the dial, driven by a program wheel system that partially obscures the moon disc's indications to simulate the natural appearance of the moon's illuminated surface, using multiple occultation discs arranged concentrically or non-concentrically to achieve a more realistic display.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional moon phase indicators use a simple rotating moon disc with two light circles against a dark background, then the device complexity is low and manufacturing is easy, but the accuracy of representing the actual appearance of moon phases is poor

Engineering Contradiction:
Improveaccuracy of moon phase representationVSAvoidcomplexity of indication mechanism
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The moon disc is segmented into multiple zones representing different moon phases (new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, waning crescent), with each zone containing specific visual elements (light circles, dark areas, convex/concave boundaries) that correspond to the actual appearance of the moon at that phase. This segmentation allows accurate representation of all phases while maintaining a manageable structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The aperture base with its concave sections acts as an intermediary element that modifies the visual presentation of the moon disc. By strategically positioning and shaping these concave sections, the mechanism transforms the simple rotating disc into an accurate moon phase indicator without requiring complex electronic or optical components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If traditional moon phase indicators use a semi-circular aperture with a simple moon disc, then the manufacturing cost is low and production is simple, but the display accuracy of moon phases does not correspond to reality

Engineering Contradiction:
Improvedisplay accuracy of moon phasesVSAvoidease of manufacturing the indication mechanism
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The moon disc is divided into distinct phase zones with specific visual characteristics (light circles for illuminated portions, dark areas for shadowed portions, convex and concave boundaries for phase transitions). This segmentation enables accurate moon phase representation while keeping each zone's design relatively simple and manufacturable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The visual parameters of the moon disc (position and size of light circles, shape of boundaries between light and dark areas) are carefully designed to match the actual geometric parameters of moon phases as seen from Earth. This parameter optimization achieves realistic display without requiring complex manufacturing processes.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If traditional indicators represent all waxing and waning phases with a single concave symbol, then the device structure is simple, but the representation does not correspond to the actual appearance of the moon's phases

Engineering Contradiction:
Improverealism of moon phase appearanceVSAvoidstructural complexity of the mechanism
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The moon disc is segmented into eight distinct phase zones, each with unique visual characteristics that accurately represent the corresponding moon phase. This includes different configurations of light circles, varying boundary shapes (convex for gibbous phases, concave for crescent phases), and appropriate dark area proportions. This segmentation achieves realistic representation while maintaining a relatively simple rotating disc structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The moon disc design incorporates asymmetric visual elements that reflect the actual asymmetric appearance of moon phases. For example, the waxing phases show increasing illumination from right to left, while waning phases show decreasing illumination in the reverse pattern. The boundaries between light and dark areas vary in curvature (convex or concave) depending on the specific phase, accurately mirroring the moon's real appearance.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2392976B1Mechanism for indication of the lunar phases
Publication Date: 2021.08.25 DE LA MFG DHORLOGERIE AUDEMARS PIGUET & CIE
  • EP2392976B1 patent drawingFigure 1a~2h
  • EP2392976B1 patent drawingFigure 3a~3d
  • EP2392976B1 patent drawingFigure 3e~4h

AI summary

The present invention relates to a moon phase indicator mechanism, particularly for a mechanical watch, comprising a moon disc (1) and a dial (3) having a substantially semi-circular aperture (3.1). The moon disc (1) is rotated so as to display the markings (1.1, 1.2) inscribed on the moon disc (1) through the aperture (3.1) to indicate the phases of the moon. Furthermore, the mechanism includes at least one first occultation disc (2.1, 2.2) rotatably housed at least partially between said moon disc (1) and said dial (3), and a drive gear (4) driving said at least first occultation disc (2.1, 2.2) so that the indications (1.1, 1.2) inscribed on the moon disc (1) are at least partially occulted during certain phases of the operation of the mechanism so that the indications (1.1, 1.2) appearing through the aperture (3).1) correspond substantially to the natural appearance of the moon throughout the entire lunar cycle. The present invention also relates to a timepiece comprising such an indication mechanism.