Moon phase indicator for watch movement

Abstract

The present invention relates to a moon phase indication mechanism (1) comprising a moon (4), a mask (6) and a drive arrangement arranged to move said mask (6) and said moon (4) during each lunar cycle according to the following sequence: a) said moon (4) and said mask (6) are together in an initial position, in a new moon configuration, said moon (4) being gradually disengaged from said mask (6) and driven in the middle of a given lunar cycle until it is positioned in a final position, in a full moon configuration; b) said mask (6) is driven to cover said moon (4) until it is positioned in said final position, the new moon configuration, at the end of said given lunar cycle; c) The moon (4) and the mask (6) are driven rapidly back to their initial position, the new moon configuration.

Description

[Technical field]

[0001] The present invention relates to a display mechanism for a timepiece movement, said display mechanism comprising a disk-shaped display of the moon, a mask suitable for covering the display of the moon, and a drive for the mask arranged to be able to move it along a predetermined trajectory extending from an initial position to a final position, such that the display of the moon and the mask are able to show, along the trajectory, a full moon configuration, in which the display of the moon is completely visible, and a new moon configuration, in which the display of the moon is completely masked.

[0002] The invention also relates to a timepiece movement equipped with such a display mechanism, and to a timepiece equipped with such a timepiece movement. [Background technology]

[0003] Such display devices have already been disclosed in the prior art.

[0004] As an example, utility model CN202548538U presents a moon phase display mechanism including the above characteristics. In particular, the display mechanism disclosed therein includes a fixed display of the moon carried by a corresponding clock face, in front of which moves a mask carried by an arm driven to exhibit periodic retrograde displacements. More precisely, the mask is driven to exhibit the following displacements during each period, which is equal during the period of the lunar cycle: starting from an initial full moon configuration, the mask is driven in a counterclockwise rotational direction from the initial position, gradually covering the moon display, until it is driven to a new moon configuration, the drive still continuing until a final position of a new full moon configuration, where the moon display is again completely clear. The mask is then rapidly rotated clockwise (i.e. retrograde with reference to the slow counterclockwise drive phase) and returned to its initial position, still in the full moon configuration, before starting a new cycle.

[0005] Patent publication EP1692574B1 describes another moon phase display mechanism having the above characteristics. More specifically, this mechanism includes a moon display carried by a first arm and a mask carried by a second arm. Each arm is driven in a first slow movement in the opposite direction from a first full moon configuration to a second full moon configuration, passing progressively through a waning moon phase, a new moon configuration and then a waxing moon phase. Once the second full moon configuration is reached, the moon display and mask move rapidly in a retrograde manner, returning to the first full moon configuration after a duration equal to one lunar cycle before starting a new cycle. Thus, compared to the one described above, this mechanism reduces the footprint of the moon phase display, since the angular sector covered by the mask is reduced by the fact that the moon display is also driven in the opposite direction to that of the mask.

[0006] The main purpose of these display mechanisms is to reduce the size of the moon phase indications on the clock face, while providing the observer with a relatively realistic indication of the moon's phases as they actually appear to the observer, but without taking into account the displacement of the moon in the sky throughout a given lunar cycle.

[0007] Patent publication CH710450B1 describes a further construction of the mechanism for displaying the phases of the moon, aimed at improving realism by providing a lunar orbital display to symbolize the relative rotation between the Earth's surface and the Moon. For this purpose, the display mechanism comprises a disk constituting the dial of the corresponding watch, with an opening through which the lunar display is visible, and driven to rotate on itself in 24 hours. This mechanism further comprises a mask, driven in 24 hours around the dial, whose orientation does not change substantially, and which is simultaneously driven to move to the opposite side of the opening in order to display the phases of the moon in periods of duration equal to that of the lunar cycle. This mechanism is more realistic than the preceding mechanism, but its readability is comparable to that of the previous mechanism, due to the reduced size of the lunar display, since it moves along a completely circular orbit. The gain in realism also means that the display mechanism takes up considerably more space, and since the entire dial is driven in rotation, it is impossible to imagine the addition of further complications, which are intended to display the starry sky.

[0008] As a result, there remains a need for alternative moon phase display mechanisms that are realistic, legible, dynamic, and compact enough to allow for the addition of further complexity. Summary of the Invention [Problem to be solved by the invention]

[0009] The main object of the invention is to propose an alternative display arrangement to known display devices in order to produce a realistic and highly legible watch with an original appearance at the same time. [Means for solving the problem]

[0010] The invention therefore relates in particular to a display mechanism of the type mentioned above, said display mechanism comprising: a lunar display member carrying a representation of the lunar moon; and a lunar display member drive configured to move the lunar display member along the predetermined trajectory between the initial position and the final position; wherein the mask and the representation of the moon are configured to move during each lunar cycle according to the following sequence: a) in a new moon configuration, with said lunar representation and said mask both in said initial position, said lunar representation being driven along said orbit and gradually decoupled from said mask until, midway through a given lunar cycle, it is positioned in said final position, a full moon configuration; b) said mask is driven along said orbit to gradually cover said representation of the moon until it is positioned in said final position, a new moon configuration, at the end of said given lunar cycle; c) The moon display and the mask are both driven rapidly back to the initial position, new moon configuration, beginning a new sequence.

[0011] Thanks to these features, the display mechanism according to the invention presents a different operating sequence to that of previous display mechanisms, since it is able to accommodate the lunar representation and the orbital range covered by the mask within a sector connecting their centers, when positioned adjacent to each other in front view, while maintaining an optimized footprint level.

[0012] According to a preferred embodiment, said lunar display member is a rotating dial and said mask is carried by a frame capable of carrying a surface displaying information other than the phases of the moon, and is arranged to cover a part of said rotating dial other than said lunar display. It is therefore advantageous to provide that said lunar display has a diameter representing at least 50%, preferably at least 60%, of the radius of said rotating dial.

[0013] Generally speaking, the representation of the moon (4) and the mask (6) are preferably driven retrogradely during step c) with reference to their directions of movement during steps a) and b).

[0014] Preferably, the moon display and the mask are actuable substantially simultaneously in step c).

[0015] Advantageously, the drive of said moon display member comprises a feeler held against a guide surface of a cam, defining at each instant an angular orientation of said feeler under the effect of the action of an elastic return member (46); It may be provided that the feeler is integral with teeth arranged to engage a lunar drive wheel, the angular orientation of the lunar drive wheel determining the angular orientation of the lunar display member.

[0016] In this case, the guide surface may have a first portion of increasing radius, followed by a second portion of substantially constant radius and a hollow or radial third portion connecting the first and second portions.

[0017] Thus, the drive of said mask comprises an additional feeler held in abutment against a guide surface of an additional cam, defining at each instant an angular orientation of said additional feeler under the effect of the action of an elastic return member; It is further possible to provide that the additional feeler is integral with teeth arranged to engage a drive wheel of the mask, and the angular orientation of the drive wheel of the mask determines the angular orientation of the mask.

[0018] In this case, it can also be envisaged that the guide surface of the additional cam (52) has a first portion of substantially constant radius, then a second portion of increasing radius and a hollow or radial third portion connecting the first and second portions.

[0019] It may then be particularly advantageous to provide that the indication mechanism comprises a kinematic connection between the cam and the further cam, and that the first and second portions of the guide surface of the cam (30) and the first and second portions of the guide surface of the further cam all have substantially equal angular extent.

[0020] Furthermore, in this case, the indicator mechanism comprises a bearing surface integral with one of the feeler and the additional feeler and abuttable against a stop surface integral with the other feeler; wherein said feeler and said further feeler are arranged to synchronise movement of said moon display member and said mask in step c) such that passage of said feeler, associated with said bearing surface, from said second portion to said first portion of said corresponding guide surface is coordinated with passage of said feeler, associated with said stop surface, from said second portion to said first portion of said corresponding guide surface.

[0021] In a preferred embodiment, the display mechanism may be provided with a latitude adjustment device arranged to adjust in response to predetermined user movements of a latitude adjustment member to correct the angular orientation of said moon display member and said mask.

[0022] In this case it is advantageous to provide that the display mechanism further comprises a latitude indicating member which indicates the set latitude at each instant, said latitude adjustment device also being arranged to control the position of said latitude indicating member.

[0023] Generally speaking, it is preferable to provide that the lunar representation and the predetermined orbit traveled by the mask is circular.

[0024] The invention also relates to a timepiece movement equipped with a display mechanism (1) including the characteristics described above, and to a timepiece equipped with such a timepiece movement. [Brief description of the drawings]

[0025] Further characteristics and advantages of the invention will appear more clearly on reading the following detailed description of preferred embodiments, with reference to the accompanying drawings, given by way of non-limiting example, in which:

[0026] [Figure 1] 1 shows a schematic diagram illustrating the overall working principle of a display mechanism according to a preferred embodiment of the present invention; [Diagram 2] 1 illustrates a simplified overall front view of a portion of a display mechanism according to a preferred embodiment of the present invention; [Diagram 3] FIG. 3 shows a simplified exploded perspective view of a detail of a first configuration of the display mechanism shown in FIG. 2; [Diagram 5] FIG. 3 shows a simplified exploded perspective view of a detail of a third configuration of the display mechanism shown in FIG. 2; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Figure 1 shows a schematic diagram illustrating the overall working principle of a display mechanism according to a preferred embodiment of the present invention. It should be understood that Figure 1 and the following detailed description thereof are provided by way of example, and those skilled in the art can make justifications according to their own needs without necessarily departing from the scope of the invention defined by the claims.

[0028] The diagram in Figure 1 consists of three rows placed one above the other.

[0029] The top row shows how the Moon appears in the sky when it is at its zenith (perceivable due to the continuous change in orientation caused by the Earth's rotation) at latitudes around 45 degrees, starting with the first day of a new lunar cycle, which begins with the new moon, then on the 4th, 7th, 11th, 15th (full moon), 19th, 22nd, 25th, and 29th (next new moon).

[0030] The next line (centre) shows a diagrammatic representation of the phases of the Moon at the same moment along its lunar cycle, always at its zenith.

[0031] The bottom row represents in a simplified and schematic manner an implementation of a moon phases display mechanism 1 according to a preferred embodiment of the invention, allowing a reliable and realistic display of the moon phases with reference to what is observable in the sky when the moon is located at the zenith. The configuration of the display mechanism is not shown for all days of the lunar cycle illustrated in the first two rows, but only for days 1, 7, 15, 22 and 29, for reasons of simplicity and legibility.

[0032] The display mechanism 1 has a lunar display 4 and here, by way of non-limiting illustration, comprises a lunar display member 2 taking the form of a rotating dial.

[0033] The mask 6 is placed above the rotating dial (from the point of view of the observer of the corresponding watch) so that in a particular configuration it can at least partially cover the lunar display 4. Here, the mask 6 is carried by a frame (reference numeral 8 in FIG. 4) which is driven in rotation in a suitable way, making it possible to display the phases of the moon at any given moment. By way of non-limiting example, the mask 6 takes the form of a disk whose diameter is equal to or slightly larger than the lunar display 4. Two further disks 10 and 12, also carried by the frame, are represented by way of non-limiting illustration. In particular, the disks 10 and 12 can set up counters which can advantageously display additional information, whatever their nature, temporal or otherwise (current time, date or other calendar information, power saving, etc.). The skilled person will for example be able to implement a display mode in relation to the disks 10, 12 such that the orientation of said display remains constant at all positions of the disks on the dial. Structures for achieving such an effect are known in the prior art. The above-mentioned patent publication CH710450B1 describes examples relating to the display of moon phases, and a person skilled in the art will not encounter any particular difficulties in adapting its teachings to implement the display of information other than moon phases.

[0034] According to the invention, the display mechanism 1 is arranged so that the mask 6 and the lunar display 4 move during each lunar cycle according to the following sequence: a) In a new moon configuration with both the lunar display 4 and the mask 6 in an initial position, the lunar display 4 is driven along a predetermined orbit and gradually detached from the mask 6 until it is in a full moon configuration in a final position midway through a predetermined lunar cycle. b) The mask 6 is driven along the same predetermined orbit, progressively covering the lunar representation 4 until it is positioned at the new moon configuration in the same final position at the end of a given lunar cycle.

[0035] At the end of the sequence, the lunar display 4 and mask 6 are driven to quickly return to their initial positions in the new moon configuration, thus passing from the 29th day configuration to the first day configuration and starting a new sequence.

[0036] It can be seen here that the lunar indication 4 has a large diameter with reference to that of the conventional mechanisms cited above, providing good legibility. More specifically, it is advantageous to provide that the diameter of the lunar indication represents at least 50%, preferably at least 60%, of the radius of the rotating dial carrying it.

[0037] The display mechanism 1 according to the invention thus makes it possible to realize a prominent display of the phases of the moon, without the need to display any other information. Indeed, the large dimensions of the moon display 4 and the mask display 6 affect the extent of the orbit they describe together, which is significant (it covers a little less than half the dial in the embodiment shown in FIG. 1), but the drive kinematics implemented optimize the corresponding footprint. Furthermore, the available surface area can be used to display additional information, in particular through the use of the disks 10, 1 and 2, as described above. It is noted that the mask 6 itself can also be used to display information, as described above in relation to 10 and 12.

[0038] This results in a particularly advantageous combination of features, making it possible to utilize a significant portion of the dial surface to display various items of information and also to implement a highly legible moon phase indication, whilst remaining faithful to the appearance of the moon as seen in the sky when the moon is located at its zenith.More advantageously, additional features are described below, which allow the rotating dial carrying the moon indication 4 and the frame 8 carrying the mask 6 to be manually rotated simultaneously, to adjust the orientation of the moon phase indication according to the latitude at which the wearer of a watch incorporating a display mechanism 1 according to a preferred embodiment of the invention is located.

[0039] FIG. 2 shows a partially simplified overall front view of a display mechanism 1 according to a preferred embodiment of the present invention.

[0040] Without departing from the spirit of the present invention, the display mechanism 1 may be integrated directly into the watch movement or may be assembled to the basic watch movement in the form of an add-on module. For the sake of brevity, the display mechanism 1 will be described below in the form of an add-on display module. It should be noted that for the sake of brevity and simplicity, the construction details of the basic watch movement will not be described herein as the implementation of the present invention does not directly depend on them.

[0041] The 24-hour wheel 20 is driven by a clockwork wheel (not visible) which rotates itself once in 24 hours. The 24-hour wheel 20 carries a finger 22 designed to cooperate with a moon-star 24 so that when the 24-hour wheel rotates counterclockwise as in Figure 2, it rotates one step per day. The finger 22 has a special structure which allows it to step back when it encounters the moon-star 24 while the 24-hour wheel 20 is rotating clockwise (especially when correcting the current time).

[0042] The moon star 24 in turn cooperates with a reduction gear 26 which is disposed in engagement with a moon cam gear 28 which includes a groove which defines a moon cam 30 .

[0043] FIG. 3 shows a simplified exploded perspective view of part of the display mechanism 1 so that the function of the moon cam 30 can be better understood, and in particular how it drives the moon display member 2.

[0044] The display mechanism 1 comprises a lunar rocker 32 arranged on a frame element (not shown) so as to be able to pivot along an axis of rotation 34. The lunar rocker 32 carries a finger 33 which engages the lunar cam 30 and acts as a feeler by being held in abutment against at least one of its walls, the latter defining a guide surface for the lunar rocker 32. The latter also carries a toothed sector 36 arranged to mesh with a pinion 38 of a drive wheel 40 of the lunar display member 2, with which its wheel 42 meshes via an intermediate wheel 44 (the meshing is better visible in FIG. 2).

[0045] Furthermore, a resilient return member 46 is kinematically linked to the lunar display member 2 for exerting a resilient return force on the latter tending to hold the feeler against the guide surface of the lunar cam 30 .

[0046] It is also clear from FIG. 3 that the lunar cam 30 has a spiral shape having a first portion extending over substantially half its length and having an increasing radius, then a second portion extending over substantially half its length and having a constant radius, and then a third portion having a hollow or radius, allowing the fingers 33 to drop from the second portion onto the first portion at the end of the lunar cycle.

[0047] Thus, when the lunar cam gear 28 is driven from the 24-hour wheel 20, in a clockwise direction of rotation as seen in Figure 3, the lunar cam 30 presents an increasing radius to the feeler from the beginning of the first portion, causing the lunar rocker 32 to rotate counterclockwise and the lunar display member 2 to rotate clockwise. During this phase, the elastic return member 46 stores mechanical energy.

[0048] When the feeler reaches the second part of the lunar cam 30, the latter continues to rotate without further rotating the lunar rocker 32. Then, the lunar display member 2, and therefore the lunar display 4, remains stationary.

[0049] When the feeler reaches the third portion of the lunar cam 30, the elastic return member 46 releases the stored mechanical energy by causing the feeler to drop to the level of the first portion of the lunar cam 30, allowing the lunar rocker 32 to rapidly rotate in a clockwise rotational direction as seen in FIG. 3 and to be released via the lunar display member 2 and its drive wheel 40.

[0050] Returning to FIG. 2, it can be seen that moon cam gear 28 is disposed in engagement with mask cam gear 50 which includes a groove that defines an additional mask cam 52 .

[0051] FIG. 4 shows a simplified exploded perspective view of part of the display mechanism 1 and allows a better understanding of the function of the additional mask cam 52 and in particular how it drives the frame 8 carrying the mask 6 .

[0052] The display mechanism 1 comprises a mask rocker 54, which is arranged on a frame element (not shown) and is pivotable about a rotation axis 56. The mask rocker 54 carries a finger (not visible) which performs the function of an additional feeler by being engaged by the additional mask cam 52 and held against at least one of its walls, the latter defining a guide surface for the mask rocker 54. The latter also carries teeth 58 arranged to engage with a pinion 60 of a drive wheel 62 of the frame 8, which wheel 64 is kinematically connected via a transmission wheel 66 and a crown gear 68 intended to be directly integral with the frame 8.

[0053] In addition, a resilient return member 70 is kinematically connected to the crown gear 68 and applies a resilient return force to the frame 8 tending to hold the additional feeler against the guide surface of the additional mask cam 52 .

[0054] From FIG. 4 it is also clear that the additional mask cam 52 has a helical shape with a first portion extending over substantially half its total length (at the level of the central axis) and having a constant radius, then a second portion extending over substantially half its total length and having an increasing radius, and then a third portion having a hollow or radial shape, allowing an additional feeler to fall from the second portion onto the first portion at the end of the lunar cycle.

[0055] Thus, when the mask cam gear 50 is driven from the 24-hour wheel 20 via the lunar cam gear 28, in a counterclockwise rotational direction in the view of FIG. 4, the additional mask cam 52 presents a constant radius to the additional feeler from the beginning of the first part, resulting in no rotation of the mask rocker 54 and therefore no rotation of the mask 6 during a given half of the lunar cycle.

[0056] When the feeler reaches the second part of the additional mask cam 52, the latter presents an increasing radius to the additional feeler, causing the mask rocker 54 to rotate counterclockwise in the view of Figure 4 and thus the frame 8 and therefore the mask 6 to rotate clockwise. During this phase the elastic return member 70 stores mechanical energy.

[0057] When the feeler reaches the third portion of the additional mask cam 52, the elastic return member 70 can release the stored mechanical energy by rapidly rotating the mask rocker 54 in a counterclockwise rotational direction in the field of view of FIG. 4 via the crown gear 68 and the transmission wheel 66, thereby returning the additional feeler to the level of the first portion of the additional mask cam 52.

[0058] As already mentioned, the mask 6, and the disks 10 and 12 can be used for the additional display of any kind of information, temporal or otherwise. In these three disks, various holes and recesses are shown, by way of non-limiting illustration, (to allow, inter alia, the attachment of gears, springs and the passage of a set of needles).

[0059] Referring again to FIG. 2, it can be seen that the mask rocker 54 comprises a beak defining a stop surface 74 arranged so as to be able to cooperate with a bearing surface 76 of the lunar rocker 32, here defined by a pin. The cooperation between these stop surfaces and the bearing surface ensures a good synchronization between the retrograde returns of the two rockers 32 and 54. In fact, it can be seen that in the configuration of the indicator mechanism 1 shown in FIG. 2, if one tries to release the lunar rocker 32, for example in the event of an impact, before the mask rocker 54, when the feeler is close to the end of the second part of the corresponding cam, it will not be able to fall into the third part of the corresponding cam, due to the contact between its bearing surface 76 and the stop surface 74 of the mask rocker 54.

[0060] Advantageously, the display mechanism 1 includes a compensation member for the moon phase display, here comprising a compensation rocker 80 carrying a retractable pawl 82 arranged to act directly on the moon star 24. The compensation rocker 80 has an actuation face 84 designed to receive a pulse in response to an appropriate actuation by the user, after which the compensation rocker 80 pivots to advance the moon star 24 by at least one step per actuation.

[0061] Advantageously, the display mechanism 1 according to a preferred embodiment of the present invention further comprises a latitude adjustment device arranged to adjust and correct the angular orientation of the lunar display member 2 and the mask 6 in response to a predetermined user action on the latitude adjustment member.

[0062] This adjustment device can be seen more clearly in FIG. 5, which shows its main components in a simplified exploded perspective view.

[0063] The latitude adjustment device comprises a compensating rocker 90 having an actuating surface 92 intended to receive impulses from the user via a compensator (not visible), for example to pivot on a frame member.

[0064] The correction rocker 90 carries an actuating beak 94 arranged to act on a main gear 96 of a latitude correction wheel 98, advancing the latter at least one step for each impulse applied by the user. A conventional jumper 100 is used to hold the latitude correction wheel 98 in a given position by cooperating with that main gear 96 as well.

[0065] Half of the teeth of the main gear 96 include extensions oriented substantially parallel to the direction of the axis of rotation of the latitude correction wheel 98 , while the latter includes an internal secondary gear 102 .

[0066] The two gears 96, 102 are arranged to cooperate with a drive wheel 104 of a latitudinal indicator (not shown) through a toothed ring 106 with which the latter is intended to be integrated. The latitudinal indicator can carry an indication designed to cooperate with a fixed latitudinal graduation scale, or can carry a latitudinal graduation scale designed to cooperate with a fixed indication and display a set latitude value.

[0067] Drive of the drive wheels 104 is achieved via a lower star (hidden in FIG. 5), while the drive wheel set comprises a main star 108 arranged in engagement with the wheels 64 of the drive wheels 62 of the frame 8, as shown in FIG. 2.

[0068] The drive wheel 104 also includes a pinion 110 which drives a toothed ring 106 .

[0069] The toothed ring 106 in turn drives a lunar drive wheel 112 via the latter's pinion 114. The lunar drive gear 112 also comprises a star 116 arranged in mesh with the wheel 42 of the drive wheel 40 of the lunar display member 2. Each of the drive wheels 40, 62 advantageously includes a friction between that wheel and the pinion, allowing the wheel to only rotate during latitude adjustment.

[0070] Thus, when the user applies an impulse to the correction rocker 90, it causes the lunar display member 2 and the frame 8 carrying the mask 6 to rotate simultaneously in the same rotational sense, without compensating for the positions of the lunar display 4 and the mask 6 along their orbits.

[0071] After a certain number of impulses, the gears of the latitude correction wheel 98 engaging with the lower star of the drive wheel 104 change, resulting in a change in the direction of rotation of the latter. Such a design makes it possible, by appropriate indexing of the mechanism, to correct the latitude over its entire range of values ​​without changing the way in which the corresponding control element, in this case the compensator, is operated. For example, starting with an initial latitude setting of 45 degrees, the first impulse increases its value until it reaches 90 degrees. Then, the next impulse decreases the latitude value, allowing the user to decrease it to -90 degrees before increasing it again by continuing to apply impulses to the compensator.

[0072] A double jumper 118 is arranged to cooperate with the drive wheels 104 and 112 to ensure orientation in a set position. It is of course possible to provide two independent jumpers as an alternative.

[0073] The above features make it possible to create a moon phase indication mechanism that is original in appearance and faithful to actual observations of the moon in the sky, while providing excellent legibility without impeding the addition of additional clutter to the face of a corresponding clock.

[0074] The above description is intended to describe specific embodiments as a non-limiting description, and the invention is not limited to the implementation of the specific features just mentioned, such as, for example, the implementation of additional disks carried by the frame, or even their number in any case, or their shape (not limited to disks). Moreover, the display mechanism just described can be implemented without a latitude adjustment mechanism without departing from the scope of the invention defined by the claims. In this case, the mechanism can be customized for each purchaser, for example, with a latitude setting corresponding to his place of residence. If a latitude setting mechanism is implemented, it can also be envisaged that it is actuated by the rotation of an external control crown gear in either direction, as an alternative to the one described above.

Claims

1. A moon phase indicator mechanism (1) for a timepiece movement, comprising: Display of the moon in the form of a disk (4); a mask (6) suitable for covering said representation of the moon (4); A mechanism for indicating phases of the moon (1), comprising: a drive for the mask (6) configured to move the mask (6) along a predetermined trajectory extending from an initial position to a final position, the drive for the mask (6) causing the lunar representation (4) and the mask (6) to indicate, along the trajectory, a full moon configuration in which the lunar representation (4) is completely visible, and a new moon configuration in which the lunar representation (4) is completely covered, The moon phase display mechanism (1) a lunar display member (2) carrying said lunar display (4) and a drive for said lunar display member (2) configured to move said lunar display member (2) along said predetermined trajectory between said initial position and said final position, said mask (6) and said lunar representation (4) are arranged to move during each lunar cycle according to the following sequence: a) in a new moon configuration, where the lunar representation (4) and the mask (6) are both located in the initial position, the lunar representation (4) is driven along the orbit and gradually decoupled from the mask (6) until, in the middle of a given lunar cycle, it is positioned in the final position, the full moon configuration; b) said mask (6) is driven along said orbit, gradually covering said lunar representation (4) until it is positioned in said final position, the new moon configuration, at the end of said given lunar cycle; c) A moon phase display mechanism, whereby said moon display (4) and said mask (6) are both driven to rapidly return to said initial position, new moon configuration, starting a new sequence.

2. 2. A display mechanism (1) according to claim 1, characterized in that the moon display (4) and the mask (6) are driven retrogradely in step c) with reference to their directions of movement in steps a) and b).

3. 3. A display mechanism (1) according to claim 1 or 2, characterized in that in step c) the moon display (4) and the mask (6) are driven substantially simultaneously.

4. said device for driving said month display member (2) comprises a feeler held in abutment against a guide surface of a cam (30) and defining at each instant an angular orientation of said feeler under the effect of the action of an elastic return member (46), 4. An indication mechanism (1) according to any one of claims 1 to 3, characterized in that the feeler is integral with a tooth (36) arranged to engage a lunar drive wheel (40), the angular orientation of which determines the angular orientation of the lunar display member (2).

5. 5. The display mechanism (1) of claim 4, characterized in that the guide surface has a first portion of increasing radius followed by a second portion of substantially constant radius and a hollow or radial third portion connecting the first and second portions.

6. said device for driving said mask (6) is characterised in that it comprises an additional feeler held in abutment against a guide surface of an additional cam (52) and which, under the effect of the action of an elastic return member (70), defines at each moment the angular orientation of said additional feeler, 5. The display mechanism (1) according to claim 4, characterized in that the additional feeler is integral with teeth (58) arranged to engage with a drive wheel (62) of the mask (6), the angular orientation of the drive wheel (62) of the mask (6) determining the angular orientation of the mask (6).

7. 7. The indicator mechanism (1) according to claim 6, characterized in that the guide surface of the additional cam (52) has a first portion of substantially constant radius, followed by a second portion of increasing radius and a hollow or radial third portion connecting the first and second portions.

8. a kinematic connection between said cam (30) and said additional cam (52), An indicator mechanism (1) according to claims 5 and 7, characterized in that the first and second portions of the guide surface of the cam (30) and the first and second portions of the guide surface of the additional cam (52) all have substantially equal angular extents.

9. a bearing surface (76) integral with one of the feeler and the further feeler and capable of abutting a stop surface (74) integral with the other feeler, 9. An indication mechanism (1) according to claim 8, characterized in that the feeler and the further feeler are arranged to synchronize the movements of the moon indication member (2) and the mask (6) in step c) such that a passage of the feeler, associated with the bearing surface (76), from the second part to the first part of the corresponding guide surface is coordinated with a passage of the feeler, associated with the abutment surface (74), from the second part to the first part of the corresponding guide surface.

10. 10. A display mechanism (1) according to claim 8 or claim 9, comprising a latitude adjustment device arranged to adjust in response to a predetermined user movement on a latitude adjustment member to correct the angular orientation of the moon display member (2) and the mask (6).

11. 11. An indication mechanism (1) according to claim 10, further comprising a latitude indicating member for indicating at each instant a set latitude, said latitude adjustment device also being arranged to control the position of said latitude indicating member.

12. 12. A display mechanism (1) according to any one of claims 1 to 11, characterized in that the lunar display member (2) is a rotating dial, and the mask (6) is further supported by a frame (8) carrying a surface displaying information other than the phases of the moon, and is arranged to cover a part of the rotating dial other than the lunar display (4).

13. 13. A display mechanism (1) according to claim 12, characterized in that the lunar display (4) has a diameter which represents at least 50%, preferably at least 60%, of the radius of the rotating dial.

14. A timepiece movement equipped with a display mechanism (1) according to any one of claims 1 to 13.

15. A watch (1) comprising a watch movement according to claim 14.

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