Compact Moon Phase Display With Optical Shutter

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing moon phase display mechanisms in timepieces, particularly wristwatches, are either decorative and aesthetically distant from the actual lunar appearance or bulky, making them difficult to integrate into watch movements and not user-friendly for determining the lunar cycle.

Innovation Solution

A moon phase display mechanism using a plano-concave lens and a shutter with a curved profile, driven by a clockwork movement, provides a realistic representation of the Moon's phases by varying the visibility of a terminator through a transparent support and substrate with contrasting colors, allowing compact integration into a watch.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a sphere is used to represent the different quarters of the Moon, then a realistic representation of the Moon's phases is achieved, but the mechanism becomes thick and takes up a lot of space, making it difficult to integrate into a watch movement

Engineering Contradiction:
Improverealism of Moon representationVSAvoidthickness of mechanism
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The patent uses a flat substrate with a printed representation of the Moon instead of a physical sphere. This 2D copy of the lunar surface maintains visual realism while eliminating the volumetric constraints of a spherical object, allowing compact integration into watch movements.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The invention transitions from a 3D spherical representation to a 2D flat representation. By changing the dimensional approach, the mechanism achieves realistic Moon phase display without requiring the thickness and volume of a sphere, solving the space constraint problem.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If a two-colored sphere rotating on itself is used to display moon phases, then the face of the Moon is represented in a realistic manner, but the mechanism is thick and takes up a lot of space

Engineering Contradiction:
Improveaccuracy of Moon phase displayVSAvoidstructural complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of using a physical rotating sphere with two-colored surfaces, the patent creates a 2D printed copy of the Moon's surface on a flat substrate. This eliminates the need for complex rotating mechanical structures while maintaining accurate Moon phase representation through optical means.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The invention replaces the mechanical rotation of a sphere with an optical system involving a lens and a movable shutter. This substitution eliminates complex mechanical rotating parts while achieving the same functional result of displaying different Moon phases.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If a hand indicator pointing to phase representations is used, then the mechanism is simple and compact, but the representation bears only a distant relation to the actual appearance of the Moon

Engineering Contradiction:
Improvesimplicity of mechanismVSAvoidrealism of Moon representation
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent uses a detailed printed representation of the actual Moon surface on the substrate, creating a realistic visual copy rather than simplified symbolic representations. This allows the mechanism to remain simple while achieving high visual fidelity to the actual Moon's appearance.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The invention uses a lens with specific optical properties and a shutter system that reveals different portions of the printed Moon surface. The optical elements and lighting conditions create realistic visual effects that enhance the authenticity of the Moon representation without adding mechanical complexity.

Inventive Principle:
Principle #32Color changes

4Measurement precision

If a sphere is used for Moon phase display, then realistic representation is achieved, but it hinders the movement of hands on the surface of the dial

Engineering Contradiction:
Improverealism of Moon representationVSAvoidhand movement on dial
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

By transitioning from a 3D sphere to a 2D flat substrate, the invention eliminates the physical obstruction that would interfere with hand movement. The flat representation lies flush with the dial surface, allowing hands to move freely over it without collision or interference.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The 2D printed copy of the Moon on a flat substrate maintains visual realism while being thin enough not to interfere with the mechanical operation of watch hands. The representation is integrated into the dial plane rather than protruding into the space needed for hand movement.

Inventive Principle:
Principle #26Copying

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The mechanism offers a realistic and easily understandable representation of lunar phases, occupying less space than traditional sphere-based mechanisms and ensuring the Moon's visibility throughout the cycle, enhancing user comprehension and integration into wristwatches.

Implementation Method 1

a plano-concave lens, preferably aspherical

Methodology Applied
Scientific EffectLens focusing: Lens

Data Source

PatentEP4369113B1Mechanism for displaying the phases of the moon
Publication Date: 2025.10.01 BLANCPAIN SA
  • EP4369113B1 patent drawingFigure 1
  • EP4369113B1 patent drawingFigure 2
  • EP4369113B1 patent drawingFigure 3A~3B

AI summary

The invention relates to a moon phase display mechanism powered by a clockwork movement, this moon phase display mechanism (1) comprising a transparent support (98) having an upper face (100) and a lower face (102) extending at a distance from the upper face (100), a representation (104) of the Moon being projected onto one of the upper (100) or lower (102) faces of this transparent support (98), a substrate (106) being disposed under the transparent support (98), at a distance from its lower face (102), the moon phase display mechanism (1) also comprising a shutter (94) which is driven by drive means (72) powered by the clockwork movement and which is arranged to move between the transparent support (98) and the substrate (106), the shutter (94) and the substrate (106) having display contrasts reversed relative to each other,the shutter (94) being moved from an initial position to a final position during a lunar cycle, so as to reveal day after day to an observer the appearance of the Moon as it passes 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 (94) being returned by the drive means from its final position to its initial position at the end of the lunar cycle.