Display module by elements movable around flexible links, display system, and timepiece comprising same

Abstract

The present invention relates to a display module (1) comprising at least two display elements (32, 33) movable via a deformable joint (4) relative to a fixed frame (2) between a rest position and a display position, each display element comprising a display portion (32a, 33a) of a pattern (M) complementary to the display portion of the other display element to form said pattern in said display position. Characteristically, the display portion of each display element has a thickness e2, measured perpendicular to a formation plane P of the display elements and their deformable joints, greater than the thickness of the display elements and their deformable joints.The invention also relates to a display system comprising such a display module and an actuation device (6) arranged to cooperate with the actuator (5') of each display module (1) and move said movable display elements (32, 33) from the rest position to the display position to simultaneously form said pattern (M) on each display module (1). The invention also relates to a timepiece comprising such a display system.

Description

Field of invention

[0001] The invention relates to the general field of microtechnology and in particular the manufacture of parts by etching silicon. The invention relates more particularly to a mechanical display module comprising a plurality of elements which are mobile relative to each other around at least one deformable connection of the flexible blade type to form three-dimensional display patterns.

[0002] The invention relates in particular to the method of manufacturing such a display module.

[0003] The invention will find a particular application in the watchmaking industry, notably for the production of animated watch or clock dials. State of the art

[0004] Analogue display systems, particularly those with needles, have been known and used for decades in a multitude of applications in order to provide a direct indication, for example on a graduated scale, a dial or other system for representing a measurement value of a physical quantity such as speed, temperature, pressure, intensity, voltage or electrical resistance, of any information, or even and probably most widely for measuring time.

[0005] We also know, particularly for clocks, mechanical display systems, for example with pallets, which indicate time information by aligning numbers printed on the pallets, the latter being pivoted around an axis by gravity when locking bolts are released at each date of time to be indicated.

[0006] Other variants of displays operated by mechanical systems have also been proposed in the state of the art, mainly in the field of watchmaking. Examples include the “nail board” type digital display of the “Opus 8” model, marketed by Harry Winston SA, or the device for digitally displaying the current time by rotating a disc underlying a dial equipped with a window, as proposed in Swiss patent application CH 691833 A5.

[0007] The applicant has also proposed in application EP 3291024 A1 a new type of monolithic display module providing a mysterious and animated display of great simplicity and compactness of construction, such a display module comprising display members movable relative to each other to form a said pattern by means of elastic deformable connections of the flexible blade type.

[0008] A disadvantage of this type of display module, however, lies in the fineness of its constituent elements, of the order of a few micrometers, which provides a popular “lace” type aesthetic effect but which can impair the readability of the patterns within the module, particularly if said patterns are also accompanied by aesthetic elements or if the color contrast between the display module and an underlying background or dial is low.

[0009] An aim of the invention is specifically to solve this problem of readability and visibility of patterns in a display module as described in EP 3291024 A1. Subject of the invention

[0010] The present invention achieves its aim by producing a display module comprising at least two display members movable by means of a deformable connection of the flexible blade type relative to a fixed frame between a rest position and a display position, each display member comprising a display portion of a pattern complementary to the display portion of the other display member to form said pattern in said display position. Typically, the display portion of each display member has a thickness e2, measured perpendicular to a plane P of formation of the display members and their deformable connections, greater than the thickness of the display members and their deformable connections at least.

[0011] According to one embodiment, the thickness e of the display portions is greater by 50% to 150% of the thickness of the display members and their deformable connections, preferably by 100% to 150%.

[0012] In practice, the thickness of the display portions of the display members is advantageously between 260 and 400 µm.

[0013] According to a characteristic of the invention, the said display member(s) movable relative to the frame cooperate with an actuating pusher arranged to transmit a force for moving this display member by elastic deformation around its deformable connection(s) from the said rest position to the said display position.

[0014] Each of the display modules can be made by molding and / or machining metal alloys, glasses, ceramics (Al 2 O 3 ), machinable and / or photocurable hard polymers (epoxy, PEEK). Preferably, however, the display modules are made of monocrystalline or polycrystalline silicon and obtained by deep silicon etching processes.

[0015] In one embodiment, the display module of the invention is obtained by deep etching of a silicon wafer, said display members being formed individually on different etching levels each defining a said plane for forming the display members and their deformable connections.

[0016] In a manner known per se, said distinct etching levels can be connected to each other by connecting beams or heels making it possible to maintain a constant gap between said levels. Thus, if we consider the different possible combinations of etching within the same silicon wafer in three orthogonal directions, we can produce a display module according to the invention comprising up to 32 different levels, thus providing a three-dimensional lacework with pattern display portions of thickness much greater than the flexible connections and other arms of the display members secured to the module frame, in order to improve the visibility and readability of the displayed patterns, for example numbers or letters.

[0017] In the context of a silicon display module, the flexible connections are for example made up of flexible blades with a width of between 2 and 50 microns, the thickness e1 of the frame and the display member(s) being greater than 30 microns. This dimensioning thus effectively provides an elastic character to the flexible blades forming the flexible connections while the portions of greater thickness of the frame and the display members are completely rigid and devoid of elastic character.

[0018] Preferably, said actuator is also integral with the frame and movable relative to it by means of a plurality of flexible and preferably flexible connections.

[0019] More preferably, said actuator extends in a radial direction relative to a geometric center of the display module.

[0020] In one embodiment, each said display module forms a monolithic part comprising said display members, the frame, the actuator and one or more deformable links connecting said display members and said actuator to the frame.

[0021] The invention further relates to a display system comprising: a. at least one display module as previously defined, provided with an actuator arranged to move said display members between their said rest position and said display position under the action of a driving force applied to said actuator, and b. an actuating device arranged to cooperate with the actuator of each display module and move said movable display members from the rest position to the display position to simultaneously form the same pattern on each display module.

[0022] In one embodiment, the display system comprises a plurality of display modules arranged concentrically around a geometric center.

[0023] In one embodiment, the actuating device is rotatable around an axis of rotation passing through said geometric center.

[0024] According to an alternative embodiment, the display system comprises a first and a second display module as previously defined, said modules being arranged concentrically around a common geometric center and superimposed relative to each other such that the display portions of the first and second modules are exactly superimposed on each other in their respective display positions.

[0025] In one embodiment, the actuating device is arranged to exert in at least one angular position around the axis of rotation a force capable of mobilizing the actuator of each display module so as to move said movable display members from the rest position to the display position to simultaneously form said pattern on each display module.

[0026] In one embodiment, the actuating device comprises a first and a second actuating mobile arranged to be mobile in rotation around the axis of rotation so as to cooperate and mobilize in at least one angular position around the axis of rotation the actuator of each display module.

[0027] In one embodiment, the actuating device, where appropriate formed of a first and a second actuating mobile, comprises a cam or a lug.

[0028] In one embodiment, the first and second actuating mobiles are rotationally indexed relative to each other about the rotation axis such that the patterns simultaneously formed on each display module are superimposed on each other.

[0029] In one embodiment, the actuating device comprises a single actuating mobile arranged to cooperate simultaneously in rotation with the actuator of each display module.

[0030] The present invention also relates to a timepiece comprising a display system as previously described. Preferably, the actuating device is kinematically linked to the hour wheel or the cannon pinion of at least one watch movement.

[0031] In such a timepiece, the pattern of each said display module is configured to display a date of time. Descriptions of the figures

[0032] The invention will be better understood by reading the detailed description of an exemplary embodiment made with reference to the appended figures, among which: there Figure 1A and 1B represent in top view a display module for a display system known from the prior art, in the rest position and in the display position respectively; the figure 2 represents in perspective a first embodiment of the display portions of the display members of a display module according to the invention, otherwise identical to the module of the prior art; The figure 3 represents an alternative embodiment of the display portions of the display members of a display module according to the invention; The figure 4 represents a second variant embodiment of the display portions of the display members of a display module according to the invention; The Figure 5a third variant of the display portions of the display members of a display module according to the invention. Description of embodiments of the invention

[0033] The present invention relates to an analog display module and system comprising display members animated by means of a mechanical actuation device. Although a preferred application of the invention relates to the field of watchmaking, it is not limited to a display of time information in a timepiece and can also be implemented in any field requiring the use of a system for displaying any information or representation in an animated form.

[0034] It has been represented on the Figures 1A and 1B a display module 1 as described in application EP 3291024 A1 in the name of the applicant.

[0035] In a simplest form, such a display module 1 consists of a module for displaying a pattern M such as a digit or a number comprising a fixed frame 2 to which at least two display members are secured, in this case three display members 31, 32, 33 to form the number “6” ( Figure 1B ). The display members 31, 32, 33 are integral with the frame 2 and each comprise a display portion 31a, 32a, 33a of the pattern M, said display portions being complementary to one another so that they form said pattern in at least one relative position of said display members 31, 32, 33.

[0036] For this purpose, the display members 31, 32, 33 are integral with the frame 2 and the members 32, 33 are also movable relative to the frame 2 by means of at least one flexible connection 4 formed by at least one flexible blade 41 between a first rest position, shown in the Figure 1A, in which the display portions of the display members 31, 32, 33 are spaced apart from each other and a display position, shown in the Figure 1B , wherein said display portions 31a, 32a, 33a are counter-imposed on each other to form and display the pattern M, in this case a number “6”.

[0037] The movement of the display members 32, 33 relative to the frame 2 around their flexible connection 4 between the rest and display positions advantageously results according to the invention from the cooperation of said display members 32, 33 with an actuating pusher 5 arranged relative to the frame 2 and to the display members to transmit a force capable of inducing a movement of said display members by elastic deformation around flexible connections also 4 following the action of an actuating device 6 separate from the display module 1, such as a cam 61 movable in rotation around an axis A on the Figures 1A and 1B , on the actuating push button 5.

[0038] The display module 1 of the invention is advantageously made up of a monolithic part formed of a rigid material, which is understood in the context of the present invention as any material whose Young's modulus is greater than 2.3 GPa. As such, the material for producing the display module 1 of the invention is silicon, monocrystalline or polycrystalline, from which it is easy, for example by deep etching processes (in particular DRIE - for Deep Reactive-ion Etching in English), to form the frame 2 and the display members 31, 32, 33 connected to each other by at least one flexible connection 4, resulting in particular advantageously from the formation during the deep etching process of one or more flexible blades 4 with a width of between 2 and 50 microns, the thickness of the frame 2 and of the display member(s) being preferably greater than 30 microns.

[0039] The movable display members 32, 33 and their display portions 32a, 33a are directly connected to the actuating pushbutton 5. The display member 31 remains identical to that of the Figures 1A and 1B .

[0040] This embodiment has the particularity of having no interruption in the movement control chain, from the actuating pusher 5 to the display portions 32a, 33a. There is no friction within the display module 1 due to the movements, only deformations, therefore a minimal loss of energy. The display portions 32a, 33b are connected to the upper ends of two rockers 32b and 33b, rotating around flexible links 4 in the form of flexible “butterfly” pivots 42 secured to the frame 2. The lower end of each of the rockers is directly connected through a set 7 of flexible serpentine blades to a plate 51 of the actuating pusher 5, which is also secured to the frame 2 by a structure 8 for guiding in linear translation with flexible blades 81.

[0041] The operation and animation of such a display module 1 result from the actuation of the pusher 5, which forms an actuator of the module 1, by an actuation device 6 comprising a cam 61 or a movable lug rotating around an axis A to impart a pushing force to it causing the display members 32, 33 and their display portions 32a, 33a to move, in particular from the rest position shown Figure 1A at the display position shown in Figure 1B .

[0042] The structural and functional principles of the display module 1 of the Figures 1A and 1B can be extended for the production of an animated circular dial I comprising a plurality of display modules 1 as shown in figure 2. Such a dial can be implemented in a timepiece such as a watch or a clock for displaying the time in an animated form with an actuating device 6 of the pushers 5 arranged to move in rotation in the center of the dial and the display modules 1 is kinematically connected to the hour wheel of a watch movement of the timepiece.

[0043] The operation of such a display system is described below with reference to Figures 1A and 1B The actuating device 6 is represented by a ring carrying on its periphery a protuberance forming a cam 61. Thus, during rotation of the ring 6, the cam 61 pushes the free end of the actuating pusher 5 ( Figure 1B) which acts as a follower contact, and causes a translational movement of the actuating pusher 5 which then pushes on the intermediate rockers 32b, 33b which pivot relative to the frame 2 and thus cause the movement of the display portions 32a, 33a towards the display position in which said display portions fit with the portion 31a to form the pattern “6” on the Figure 1B .

[0044] After the cam 61 has passed, the follower contact of the actuating pusher 5 returns to bear on the ring 6, pushed by the return forces of the flexible blades of the deformable connection 4 to the frame 2. The display portions 32a, 33a then move apart to return to the rest position ( Figure 1A ) and the pattern is no longer visible.

[0045] This creates an animated display system comprising mobile display portions over a given period to create a visual animation effect within the display.

[0046] In order to provide the most readable display possible of the patterns M formed, the present invention proposes a slight modification of the display portions 31a, 32a, 33a of the display members 3 to significantly increase their own height relative to that of the other elements of the module (frame 2, flexible connections 4, pusher 5, display members 3), and to duplicate the display portions 31a, 32a, 3a3 on several superimposed levels to create a three-dimensional effect of the display at the level of the patterns M at least.

[0047] There figure 2illustrates this improvement in its simplest embodiment, for a given display portion 32. To obtain such a display portion 32a, it is appropriate to produce the display module 1 from a silicon wafer with a thickness E of approximately 400 µm, which is then etched by deep etching processes, in particular of the DRIE type (from the acronym Dry Reactive Ion Etching in English) selectively to obtain the precise functional parts of the module, namely the frame 2, the flexible connections 4 and other actuating pusher 5 with a first thickness e1 of the order of 170 µm, while the display portions 32a are etched over the entire thickness E of the wafer, or at least over a thickness e2 greater than 50 to 150% of the thickness e1, so as to enhance the display patterns M during the assembly or juxtaposition of the display members in the display position.

[0048] It should also be noted that the display portion 32a can further undergo additional etching in order to produce a 3-level stage, thus providing three-dimensional aesthetic effects within the display portions.

[0049] A first variant embodiment of a module according to the present invention is presented in figure 3 , in which two display portions 32a, 32a' are assembled head to tail, which has the advantage of being able to reduce the size of the display portions 32a making up the pattern without affecting the resolution in the display position, but increasing the animation of the display with a greater number of moving parts adjusting to form the pattern in the display position M, the display portions having a total thickness of 400 µm.

[0050] As has been proposed in the prior art, the display modules of the invention make it possible to produce thin monolithic dials with a spectacular animated display, as well as associated display systems. The improved modules according to the invention make it possible to increase this spectacular and animated side of the display by associating in the same display system two dials or display modules according to the invention in a superimposed manner such that each dial simultaneously forms their identical display patterns M in a superimposed manner, thus providing significant depth and three-dimensionality to the display of the pattern.

[0051] Such achievements are presented as examples to the Figures 4 and 5, in which two animated dials C1 and C2 individually produced in an SOI wafer (for Silicon on insulator in English) are superimposed concentrically around a common axis C which is in practice the axis of rotation of the actuating cam 6, 61 of the display system of the invention according to the principles described in figure 1 The flexible elements have a reduced thickness e1 (120 to 170 µm) etched in a part called “Device” D of the wafer, whereas the display portions have, in accordance with the invention, a thickness e2 greater than e1, of the order of 300 to 400 µm, and are etched in the part called “Handle” H of the wafer. Thus, when the patterns M of each dial are formed, an overall pattern with a thickness of the order of 800 µm is obtained, the visibility of which is greatly increased compared to the elements formed in the Device part D.

[0052] The Handle (H) part of the wafer can undergo a second etching step, which leads to a topology on 8 levels for an animated dial, therefore a total topology on 64 levels for the set of two superimposed dials C1 + C2. This “three-dimensional lace” creation can be used to create light reflection effects on the sides of the display patterns M, in particular for example the hourly date numerals in a timepiece dial.

[0053] As indicated on the Figure 5 , the animation movements of each of the dials are preferably carried out in opposite directions so as to amplify the “spectacular” aspect of the display. More specifically, each dial C1, C2 can be engraved such that the display portions 32a of the display patterns move opposite each other from their rest position to the display position. In addition, it is advantageous as shown in Figures 4 and 5that the dials C1 and C2 are arranged in such a way that their “Device” part D, comprising frame 2, pusher 5, and flexible links 4 among others are closest to each other, which makes it possible to envisage the assembly of the dials together via a ring whose thickness can fix the distance between the two dials, the ring then being able to serve as a mounting and indexing member with respect to an actuating device of the display system of the invention, for example a cam secured to the axis of the hour wheel or the cannon pinion of a watch movement.

[0054] This allows you to create highly readable, multi-level animated display systems with spectacular aesthetic animation effects.

Claims

1. A method of manufacturing a display module (1) from a silicon wafer, the display module (1) including at least two display members (32, 33) movable via a deformable link (4) relative to a fixed frame (2) between a rest position and a display position, each display member including a display portion (32a, 33a) of a pattern (M) complementary to the display portion of the other display member to form said pattern (M) in said display position, comprising the step of a deep etching on a first thickness e1 of the silicon wafer, to obtain the fixed frame (2), the deformable link (4) and an actuating push-button (5), the display portions (32a, 33a) being etched on a second thickness e2 of the silicon wafer greater than the first thickness e1 .

2. Method of manufacturing according to claim 1, the silicon wafer having a thickness of 400 µm.

3. Method of manufacturing according to one of claims 1 or 2, the first thickness e1 being 170 µm.

4. Method of manufacturing according to one of claims 1 to 3, the second thickness e2 being 50 to 150% greater than the first thickness e1.

5. Method of manufacturing according to one of claims 1 to 4, the stage comprising three levels.

6. Method of manufacturing according to one of claims 1 to 5, comprising a head-to-tail assembly of the display portions (32a, 33a).

7. Method of manufacturing according to claim 6, the display portions all having a thickness of 400 µm.

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