阅读说明：本技术 用于制造包括至少一个三维元件的表盘的方法 (Method for manufacturing a dial comprising at least one three-dimensional element ) 是由 B·拉亚尔 C·爱门艾格 F·让诺勒 于 2018-11-30 设计创作，主要内容包括：用于制造包括至少一个三维元件(30)的表盘(11)的方法,该方法包括以下步骤：·-利用控制单元(2)生成用于打印装置(3)的至少一个控制命令的生成步骤(44),所述打印装置(3)用于再现与设置有至少一个三维元件(30)的所述表盘(11)有关的参考数字图形表示(9a),以及·-利用打印装置(3)在形成所述表盘(11)的支承元件上构建包括打印颗粒的至少两个叠加层的构建步骤(45),以及·-从所述支承元件上移除表盘(11)的移除步骤(52)。(Method for manufacturing a dial (11) comprising at least one three-dimensional element (30), the method comprising the steps of: -a generation step (44) of at least one control command for a printing device (3) with a control unit (2), said printing device (3) being intended to reproduce a reference digital graphic representation (9a) relating to said dial (11) provided with at least one three-dimensional element (30), and-a building step (45) of at least two superimposed layers comprising printing particles on a support element forming said dial (11) with the printing device (3), and-a removal step (52) of the dial (11) from said support element.)

1. A method for manufacturing a dial (11) comprising at least one three-dimensional element (30), the method comprising the steps of:

-a generation step (44) of generating, with a control unit (2), at least one control command for a printing device (3), said printing device (3) being intended to reproduce a reference digital graphic representation (9a) relating to said dial (11) provided with at least one three-dimensional element (30), and

-a building step (45) of building at least two superimposed layers comprising printed particles on a support element using a jet of particles coming from a printing device (3) to form said dial (11), and

-a removal step (52) of the dial (11) from the support element.

2. Method according to the preceding claim, characterized in that said building step (45) comprises a sub-step (46) of producing a dial blank (10, 20), said sub-step (46) comprising the following phases:

-an application phase (47) of at least one layer of particles on the support element;

-a treatment phase (48) of treating the at least one layer of particles printed.

3. Method according to the preceding claim, characterized in that at least one layer of particles is applied continuously on the support element in order to obtain a solid dial blank (10).

4. Method according to claim 2, characterized in that the printing particles are applied discontinuously on the support element to obtain a pierced-out dial blank (20).

5. Method according to any one of claims 2 to 4, characterized in that said building step (45) comprises a sub-step (49) of generating at least one three-dimensional element (30), said sub-step comprising the following stages:

-an application phase (50) of selectively applying at least one layer formed by at least one type of particles on said dial blank (10, 20);

-a treatment phase (51) of treating said at least one layer formed by said at least one particle.

6. Method according to the preceding claim, characterized in that at least one layer formed by at least one type of particles is applied discontinuously on the dial blank (10, 20).

7. Method according to any one of the preceding claims 5 and 6, characterized in that said application phase (47, 50) is intended to cause said control unit (2) to execute said at least one control command comprising data (9b) describing the layers constituting said reference digital graphic representation (9a) to be reproduced.

8. Method according to any one of claims 5 to 7, characterized in that said application phase (47, 50) is used for depositing at least one ink comprising said at least one particle.

9. Method according to the preceding claim, characterized in that said ink comprises a fluid carrying said at least one particle, said fluid being chosen from solvents, viscoelastic polymers, oils, water and/or aqueous solutions.

10. Method according to any one of claims 5 to 9, characterized in that said treatment stage (48, 51) comprises a fixing sub-stage of said layers to the dial blank (10, 20) or to the support element.

11. Method according to the preceding claim, characterized in that the immobilization sub-phase is used to expose the layer to a flow of air, in particular a flow of hot air, and/or to a light radiation, in particular an Ultraviolet (UV) radiation or an infrared radiation.

12. The method according to any one of claims 1 to 11, characterized in that the particles are contained in an ink:

a coloured ink comprising coloured or coloured particles, or

A colorless or transparent or translucent ink comprising colorless or transparent or translucent particles, or

-a functional ink comprising functional particles.

13. Dial (11) comprising at least one three-dimensional element (30) obtainable by the method according to any one of claims 1 to 12.

14. Dial (11) according to the preceding claim, characterized in that it forms a single piece with said at least one three-dimensional element (30).

15. Timepiece (40) comprising at least one dial (11) according to any one of claims 13 and 14.

16. A system for manufacturing a dial (11) comprising at least one three-dimensional element (30), implementing a method according to any one of claims 1 to 12, said system (1) comprising a printing device (3) and a control unit (2), said printing device (3) being connected to said control unit (2).

17. The system (1) according to the preceding claim, characterized in that said control unit (2) comprises hardware resources and software resources, said hardware resources comprising a memory element (5), said memory element (5) containing at least one reference digital graphical representation (9a) relating to a dial (11) to be manufactured and descriptive data (9b) relating to said at least one reference digital graphical representation (9 a).

18. A computer program comprising program code instructions for carrying out the steps of the method according to any one of claims 1 to 12, when said program is executed by a control unit (2).

Technical Field

The invention relates to a method for manufacturing a dial comprising at least one three-dimensional element, and to a system for implementing the method.

The invention also relates to such a dial and to a timepiece equipped with such a dial. The invention also relates to a computer program.

Background

In the prior art, timepiece dials are generally planar, the only three-dimensional elements of which are the enchasing blocks, for example the hour number, and the graduations, arranged at regular intervals around the periphery of these dials, in order to easily read the time with respect to the angular position of the hands. The manufacture of the tesserae and the graduations remains a complex process and their placement on the dial is a cumbersome operation.

Nevertheless, the various methods of manufacturing three-dimensional elements on a dial have the advantage of overcoming the drawbacks described above.

For example, document EP 245823 discloses a method for manufacturing a dial having a three-dimensional element at least partially covered in a decorative layer. The method comprises forming a dial and then selectively modifying the surface state of the dial so as to locally change its adhesion with respect to the decorative layer. The decorative layer is then deposited directly on the whole dial, and finally, the parts of the deposited layer that do not adhere to the dial are removed.

Document EP2370865 also discloses a method for manufacturing a dial provided with three-dimensional elements, comprising the manufacture of a mask on the dial of a timepiece, the thickness of the mask corresponding to the desired thickness of the three-dimensional elements used to decorate the dial, and having at least one opening. The mask is then placed against the dial, and the openings are placed at the positions of the parts of the dial to be decorated, so that the openings of the mask are filled with at least partially amorphous material by hot working. Finally, the mask is removed to obtain the three-dimensional elements on the timepiece dial.

However, both methods are relatively complex to perform, since their implementation requires a large number of operations and requires different types of tools.

Furthermore, it should be noted that the traditional methods for manufacturing dial blanks to which three-dimensional elements are applied generally involve a plurality of operations. The dial is first stamped, for example made of aluminium or brass, so as to cut out the outline, the central hole, and the opening or openings of the dial blank, according to the type of movement. A smoothing operation is then carried out using sandpaper to remove machining residues, followed by a surface finishing operation, and then a polishing operation is carried out using a brush equipped with a cotton disc to obtain a very smooth surface.

Following the manufacturing method examples described in documents EP2370865 and EP 2457106, dial blanks manufactured according to conventional manufacturing methods have the drawback of requiring different types of tools and expertise, which requires qualified labour and significantly affects production costs.

Disclosure of Invention

It is therefore an object of the present invention to propose a method for manufacturing in a quick and simple manner a dial comprising at least one three-dimensional element, such as a decorative element or a relief pattern defined on the surface of the dial, and which also contributes to improving the large-scale, automated and cost-effective production of such a dial.

In view of this, the invention relates to a method for manufacturing a dial comprising at least one three-dimensional element, the method comprising the steps of:

-a generation step of generating, with a control unit, at least one control command for a printing device for reproducing a reference digital graphic representation relating to said dial provided with at least one three-dimensional element, and

-a building step of building at least two superimposed layers comprising printed particles on a supporting element using a jet of particles coming from a printing device to form said dial, and

-a removal step of removing the dial from the support element.

By virtue of these features, the manufacturing method thus allows to manufacture a dial comprising at least one three-dimensional element with a reduced number of operations, simple and quick to implement.

In other embodiments:

-said building step comprises a sub-step of producing a dial blank, said sub-step comprising a phase of applying at least one layer of granules on a support element and a phase of processing said at least one layer of granules printed;

-continuously applying at least one layer of particles on the support element to obtain a solid dial blank;

-applying printing particles discontinuously on the supporting element to obtain a pierced-out type dial blank;

-said building step comprises a sub-step of producing at least one three-dimensional element, said sub-step comprising an application phase of selectively applying at least one layer constituted by at least one type of particles on said dial blank and a processing phase of processing said at least one layer constituted by said at least one type of particles;

-applying discontinuously at least one layer of at least one type of particles on said dial blank;

-an application phase for causing the control unit to execute said at least one control command comprising data describing the layers constituting said reference digital graphic representation to be reproduced;

-an application phase for depositing at least one ink comprising said at least one particle;

-the ink comprises a fluid carrying the at least one particle, the fluid being selected from a solvent, a viscoelastic polymer, an oil, water and/or an aqueous solution;

-the treatment phase comprises a fixing sub-phase of fixing the layer on the dial blank or on the support element;

-a fixing sub-phase for exposing the layer to an air flow, in particular a hot air flow, and/or to optical radiation, in particular ultraviolet radiation or infrared radiation; and

the particles are comprised in an ink, such as a colored ink comprising colored or colored particles, or a colorless or transparent or translucent ink comprising colorless or transparent or translucent particles, or a functional ink comprising functional particles.

The invention also relates to a dial comprising at least one three-dimensional element, which can be obtained using such a method.

Advantageously, the dial and said at least one three-dimensional element form a single piece.

The invention also relates to a timepiece having at least one such dial.

The invention also relates to a system for manufacturing a dial comprising at least one three-dimensional element implementing said method, said system comprising a printing device and a control unit, said printing device being connected to said control unit.

Advantageously, the control unit comprises hardware resources and software resources, said hardware resources comprising a memory element containing at least one reference digital graphic representation relating to the dial to be manufactured and descriptive data relating to said at least one reference digital graphic representation.

The invention also relates to a computer program comprising program code instructions for executing the steps of the method, when said program is executed by a control unit.

Drawings

Other features and advantages of the present invention will become apparent upon reading of the various embodiments, which are provided for illustrative purposes only and are not intended to limit the scope of the invention, wherein:

fig. 1 is a schematic view of a system for manufacturing a dial comprising at least one three-dimensional element according to an embodiment of the invention;

fig. 2 is a flow chart relating to a method for manufacturing a dial comprising at least one three-dimensional element according to an embodiment of the invention;

figure 3 is a schematic view of a timepiece comprising at least one dial according to an embodiment of the invention;

fig. 4 shows a schematic view of a printing device of a system capable of contributing to the building of a solid dial blank according to an embodiment of the invention;

fig. 5A shows a schematic view of a printing device of a system capable of facilitating the building of pierced dial blanks according to an embodiment of the invention;

fig. 5B is a top view of a pierced dial blank according to an embodiment of the invention;

FIG. 5C shows a cross-section along axis A-A of FIG. 5B according to an embodiment of the invention; and

figures 6, 7, 8 and 9 respectively show views of an exemplary dial obtained according to an embodiment of the invention.

Detailed Description

With reference to fig. 1 and 3, the system for manufacturing a dial 11 of a timepiece 40 comprising at least one three-dimensional element 30 comprises a control unit 2 and a printing device 3. The dial 11 may be, for example, a solid dial or a pierced dial. In addition to the three-dimensional elements 30 contained therein, the dial may be colored, multi-colored, monochromatic, transparent or translucent. The three-dimensional element 30 may comprise arabic or roman numerals, graduations or even lettering blocks arranged on the periphery of the dial. It should be noted that the dial comprising at least one three-dimensional element is formed by a plurality of layers applied to a support element, the layers being superposed and each layer containing at least one type of particles and therefore being printed on said support element in this case. The particles, alternatively referred to as "usable particles" or "feature particles", are particles that characterize the corresponding layer with respect to at least one feature of the layer, such as its nature, texture, character, color, hue, and/or function, and the like. It will therefore be appreciated that this is the particular particle of the layer that can be formed from a variety of other types of particles other than "the useful particle".

In this system 1, a control unit 2 is connected to the printing device 3, in particular to ensure control of the device 3. The control unit 2 may be a computer or even a microcontroller comprising hardware and software resources, in particular comprising at least one processor 4 cooperating with a memory element 5. The control unit 2 is capable of executing commands to implement a computer program.

In this control unit 2, the memory element 5 contains, in addition to the computer program, data relating to at least one reference digital graphical representation 9a to be reproduced in relation to the dial 11, and descriptive data relating to said at least one reference digital graphical representation 9 a. The reference digital graphical representation 9a comprises, for example, a three-dimensional reference graphical representation or a two-dimensional reference graphical representation. It should be noted that the reference digital graphical representation 9a is generated by a design module of the system 1 connected to the control unit 2 capable of including a two-dimensional/three-dimensional digital imaging device, or the reference digital graphical representation 9a is even generated by a software tool executed by the control unit 2, allowing virtual 2D/3D modeling from photographs or images, or even allowing the design of virtual three-dimensional digital objects (for example, computer-aided design software, more commonly known as CAD software).

Such a printing apparatus 3 shown in fig. 1, 4 and 5A includes a printing part 6, a fixing part 7 and a driving part 8. The printing unit 6 comprises a plurality of printing entities, in particular inkjet cartridges, each cartridge comprising a print head 12a-12d in this embodiment, each cartridge comprising a print head 12a-12d and at least one inkjet container. In these cartridges, the ink has at least one particle that can be contained in a fluid. Such a fluid is provided to ensure that the at least one particle is carried during the ejection of the fluid from the cartridge to the support on which it has to be deposited, which in this case is the supporting element and the dial formed. The fluid may be any object capable of ensuring such entrainment. The fluid may be chosen, by way of non-limiting and non-exhaustive example, from solvents, viscoelastic polymers, oils, water and aqueous solutions. For purposes of illustration, when this is a viscoelastic polymer, this fluid is a liquid-phase viscoelastic polymer fluid that is non-polymeric and preferably capable of photopolymerization. It should be noted that in an alternative embodiment, the at least one particle may be deposited on the support without the need for such a fluid to ensure its entrainment. The ink cartridge of the printing component 6 may comprise ink, for example:

a coloured ink with coloured or coloured particles, or

Colorless or transparent or translucent inks, e.g. lacquers, with colorless or transparent or translucent particles, or

-a functional ink with functional particles selected from the group consisting of electroluminescent inks, phosphorescent inks, photoluminescent inks, conductive inks, semiconducting inks, electronically active inks, magnetic inks, photochromic inks, electrochromic inks, thermochromic inks, ionochromic inks and mechanochromic inks.

Here, as a non-exhaustive and non-limiting way, the layer formed by at least one functional particle and/or by at least one colored or pigmented particle and/or by at least one colorless or transparent or translucent particle may have:

-only white;

-a matte or bright white colour due to the presence of at least one colourless or transparent or translucent particle;

-black only;

-a matte or glossy black color due to the presence of at least one colorless or transparent or translucent particle;

since the four-color printing technology using primary colors such as cyan, magenta, yellow, and black (referred to as a CMYK system) realizes a wide variety of colors, it allows reproduction of a wide variety of colors from three basic colors, i.e., cyan called cyan, red called magenta, and yellow, plus black.

In addition, such a printing apparatus 3 can also be used to manufacture the dial 11 at a low resolution or a high resolution of 2400dpi (pixels per inch) or more.

In this printing device 3, the drive means 8 are able to move the printing means 6 in various directions with respect to the support element of the system 1 on which the dial 11 can be made. This support element, which can move in front of the print heads 12a to 12d, can be for example in the form of a non-viscous and lubricating sheet, so as to enable easy disassembly of the dial 11 after the manufacture of the dial 11 is completed. The fixing part 7 is provided to ensure the fixing of the layer formed by at least one or more particles to the supporting element or to an already existing first or initial layer on the timepiece-part 10. The fixing part 7 comprises a module capable of emitting ultraviolet radiation and/or infrared radiation and/or an air flow, in particular a hot air flow. This module is able to generate a radiation or air flow on all or part of the assembly area of the support element on which the dial 11 can be built. It should be noted that when the different inks as described above contain viscoelastic polymer fluids, the module is a photopolymerization module having a source of ultraviolet radiation, thus being able to generate ultraviolet radiation on all or part of the assembly area of the surface of the support element on which dial 11 can be built.

Such a system 1 enables implementing a method for manufacturing a dial 11 comprising at least one three-dimensional element 30, as shown in fig. 2.

The method comprises a step 41 of generating at least one reference digital graphical representation 9 a. In this step 41, the reference digital graphical representation 9a may be generated from a three-dimensional digital imaging, or when the control unit 2 executes 2D/3D virtual modeling software or software for designing a three-dimensional virtual digital object (e.g. computer aided design software, commonly known by the acronym CAD). Once generated, the reference digital graphic representation 9a is stored in the memory element 5 of the control unit 2 in the form of a digital data file. In other words, the file contains information data relating to the reference digital graphical representation 9 a.

The method then provides a step 42 of determining descriptive data 9b relating to said reference digital graphical representation 9 a. Step 42 is carried out by the control unit 2 and therefore allows the determination of descriptive data 9b which, among other things, facilitate the selection of the type or types of ink required to produce the dial on the assembly area of the support element and the direction of movement of the printing member 6 with respect to the assembly area. In this step 42, the document and in particular the information data relating to the reference digital graphical representation 9a are processed, in particular by implementing a process for digitally dividing/cutting the graphical representation 9a into at least two layers in the following directions:

-a lateral direction, which may be horizontal, vertical or inclined;

longitudinal, which may be horizontal, vertical or inclined.

More specifically, during this process, the control unit 2 determines elements that are characteristics of each layer obtained, such as:

at least one dimension of each layer, for example, for each layer, may be thickness, length, width, surface area or volume, etc.;

visual/aesthetic/structural aspects, i.e. visual and/or aesthetic and/or structural aspects of the reference graphical representation 9a, such as colour and/or texture, etc.;

physical and/or chemical functional features that dial 11, having at least one three-dimensional element 30, must have, for example, these features relating to:

electrical conductivity, semi-conductivity or insulation;

semi-conducting;

electroluminescence;

photoluminescence (e.g., reaction to ultraviolet radiation);

phosphorescence;

"X-photochromic" (photochromic, electrochromic, thermochromic, ionochromic, mechanochromic, etc.);

electrical activity;

magnetic properties;

and so on.

These characteristic elements of each layer constitute descriptive data 9b associated with the reference digital graphical representation 9a, these descriptive data being archived in the storage element 5 of the control unit 2.

The method for manufacturing this dial 11 also comprises a step 43 of selecting the reference numeral graphic representation 9a that must be reproduced on the assembly area of the support element, in order to form the dial 11 with at least one three-dimensional element 30. Thus, in the selection step 43, the reference numeral graphical representation 9a may be selected using a man-machine interface (MMI) connected to the control unit 2.

The method then provides a step 44 of generating with the control unit 2 at least one control command for controlling the printing means 3, said printing means 3 being adapted to reproduce the reference digital graphical representation 9 a. The step 44 of generating said at least one control command is performed on the basis of descriptive data 9b relating to the layer forming the reference digital graphical representation 9a to be reproduced. The at least one command comprises criteria for controlling the printing device 3, in particular the printing means 6 and the fixing means 7. These criteria include, among other things, data relating to:

the selection of an ink cartridge comprising the print heads 12a-12d required to reproduce each layer of the reference numeral graphical representation 9a and, depending on the inks they contain, in particular for reproducing the visual/aesthetic/structural aspects and/or the functional characteristics of each of these layers;

-movement of the print heads 12a-12d of each cartridge with respect to the assembly area of the supporting element for reproducing at least one dimensional and/or visual/aesthetic/structural aspect and/or functional feature of each layer of the reference numeral graphical representation 9 a;

the distance and/or position of the print heads 12a-12d of each cartridge with respect to the assembly area of the supporting element for reproducing at least one dimension and/or visual/aesthetic/structural aspect and/or functional feature of each layer of the reference numeral graphical representation 9 a;

the duration of positioning of the print heads 12a-12d of each cartridge with respect to the assembly area of the supporting element for reproducing at least one dimension and/or visual/aesthetic/structural aspect and/or functional feature of each layer of the reference numeral graphical representation 9 a;

the ink streams, in particular the number of ejected drops, ejected from the print heads 12a-12d for reproducing at least one dimensional and/or visual/aesthetic/structural aspect and/or functional feature of each layer of the reference numeral graphical representation 9 a.

Then, the method comprises step 45: by means of the ejection of particles at least from the printing device 3, at least two superimposed layers, which together comprise the printing particles, are built up on the support element, said layers forming the dial 11 with at least one three-dimensional element 30. In this step 45, the particles are sprayed onto the support element. These particles may be contained in the same nozzle or in a plurality of different nozzles of the print head. It should therefore be noted that, as mentioned above, the particles may be deposited on the support element by being contained in a fluid or in an alternative embodiment without the need for such a fluid to ensure its carrying.

Each printing particle is contained in one of the above-mentioned functional, colored and/or colorless/transparent/translucent inks. More specifically, it should be noted that a layer may be formed by at least one printing particle type only or by a plurality of different particle types, i.e. functional, colored and/or colorless/transparent/translucent printing particles.

This building step 45 comprises a sub-step 46 of producing the dial blank 10, 20. The dial blank 10, 20 comprises a substantially flat surface and therefore has no raised portions. This sub-step 46 comprises a stage 47 of applying at least one layer of granules to the assembly zone of the support element. The application of the layer may be continuous or discontinuous. As mentioned above, each particle may be a functional, coloured and/or colourless/transparent/translucent particle. It should be understood that the layer may comprise a plurality of particle types selected from functional, colored or colorless/translucent/transparent particles, which may be different or may be the same. Furthermore, this application sub-step causes the control unit 2 to execute said at least one control command comprising data describing said reference digital graphical representation 9a to be reproduced. The execution of said at least one command enables the deposition of at least one ink containing said particles and optionally other inks containing other functional, coloured or colourless/translucent/transparent particles to be controlled within the application range of the layer. Then, production sub-step 46 comprises a stage 48 of treating the at least one layer of granules directly after application stage 47. The stage 48 of treating the particle layer comprises a sub-stage of fixing the particle layer to the support element. The immobilizer stage serves to expose the particle layer to an air stream, in particular a hot air stream, and/or to light radiation, in particular ultraviolet radiation or infrared radiation. The purpose of this fixing sub-stage is therefore to transform the layer of granules, in paste or liquid state, into at least one layer of printed granules in a solid, rigid, elastic, dry, solidified and/or infusible state. This transition thus results in a layer of printed particles being obtained on the support element. It should be noted that such a transition has the advantage of being performed very quickly, typically less than one second.

More specifically, in this production sub-step 46, in particular during the execution of the application phase 47, the control unit 2 executes said at least one control command comprising data 9b describing the layers constituting said reference digital graphical representation 9a to be reproduced. Subsequently, the printing device 3 applies the layer of first particles, or the initial layer as it were, directly on the assembly area of the support element provided for this purpose, according to the at least one control instruction executed.

With reference to fig. 2 and 4, in a first alternative embodiment of the production sub-step 46 for obtaining a solid dial blank 10, the deposition/application on the assembly area of the granular layer is carried out continuously. In other words, in this alternative embodiment, during the first pass of the print heads 12a, 12b, 12c, 12d over the support element, the first layer is applied continuously onto the assembly area, thus producing a first portion of the height of the dial blank 10. The first layer of particles is then subjected to a fixed sub-phase of the treatment phase 48, in which the first layer is exposed to a flow of air, in particular a flow of hot air, and/or to light radiation, in particular ultraviolet or infrared radiation. In accordance with the at least one control command executed, during a second pass of the print heads 12a-12d over the assembly area, a layer of second granules may be applied successively to the first layer of printing granules on the support element to produce a second portion of the height of the dial blank 10. The layer of second particles is also subjected to a fixed sub-phase of the treatment phase 48 in order to transform this second layer into a layer of second printed particles on the layer of first printed particles on the support element.

In this first alternative embodiment, the application and treatment phases 47, 48 can be repeated a third time to obtain a dial blank 10 having a thickness of about 0.5mm, so as to ensure good mechanical stability of the dial 11. This operation can also be repeated a fourth, fifth or even sixth time, depending on the desired thickness of the dial blank. In general, the thickness of the solid dial blank 10 obtained by the manufacturing method according to the invention may vary between 0.3mm and 1mm or more. As a result, the number of layers of the printing particles can be varied according to the thickness of the dial blank 10. It is desirable for the minimum number of superimposed layers of printing particles to be two in order to obtain good mechanical strength of the dial 11, although depending on the properties of the ink used, it cannot be excluded that a single layer of printing particles can obtain satisfactory mechanical strength.

With reference to fig. 2 and 5A, in a second alternative embodiment of the production sub-step 46 for obtaining a pierced-out type dial blank 20 (visible in fig. 5B and 5C), the deposition/application is discontinuous over the assembly area of the layer of granules. In other words, in this alternative embodiment, during the first passage of the print heads 12a, 12b, 12c, 12d over the supporting element, a first layer is applied discontinuously onto the assembly area, so as to produce a first portion of the height of the dial blank 20. The first layer of particles is then subjected to a fixed sub-phase of a treatment phase 48 in which the first layer is exposed to a flow of air, in particular a flow of hot air, and/or to light radiation, in particular ultraviolet or infrared radiation. In accordance with the at least one control command executed, during a second pass of the print heads 12a-12d over the assembly area, a layer of second granules may be discontinuously applied onto the layer of first printed granules on the support element to produce a first portion of the height of the dial blank 20. This layer of second particles is also subjected to the fixed sub-phase of the treatment phase 48 in order to transform this second layer into a layer of second printed particles on the layer of first printed particles on the support element.

In this second alternative embodiment, the application and treatment phases 47, 48 can be repeated a third time to obtain a dial blank 20 with a thickness of about 0.5mm, so as to ensure good mechanical stability of the dial 11. This operation can also be repeated a fourth, fifth or even sixth time depending on the desired thickness of the dial blank 20. In general, the thickness of the pierced dial blank 20 obtained by the manufacturing method according to the present invention may vary between 0.3mm and 1mm or more. As a result, the number of layers of the printing particles can be varied according to the thickness of the dial blank 20. It is desirable for the minimum number of superimposed layers of printing particles to be two in order to obtain good mechanical strength of the dial 11, although depending on the properties of the ink used, it cannot be excluded that a single layer of printing particles can obtain satisfactory mechanical strength.

The building step then comprises a sub-step 49 of producing at least one three-dimensional element 30. This sub-step 49 comprises a stage 50 of selective application 50 of a layer of at least one type of particles onto said dial blank 10, 20. The selective application of said at least one layer allows to create the three-dimensional element 30 so that it has a raised portion with respect to the flat surface of the dial blank 10, 20. In other words, the application of the layer is carried out discontinuously on the dial blank 10, 20. As mentioned above, the particles may be coloured and/or functional and/or colourless/transparent/translucent. It is to be understood that the layer may comprise a variety of particle types selected from colored, functional and/or colorless/translucent/transparent particles. It should be noted that the at least one layer deposited on the dial blank 10, 20 may have a constant thickness or have a non-uniform thickness at all points. Then, production sub-step 49 comprises a stage 51 of treating said at least one layer formed by at least one type of particles directly after application stage 50. This treatment stage 51 comprises a sub-stage of fixing said layer formed by at least one type of particles on the dial blank 10, 20. The immobilizer stage serves to expose a layer of at least one particle to an air flow, in particular a hot air flow, and/or to optical radiation, in particular ultraviolet radiation or infrared radiation. The purpose of this immobilizer stage is therefore to transform a layer of at least one particle in paste or liquid state into at least one layer of printing particles in solid, rigid, elastic, dry, solidified and/or infusible state. This transformation thus results in obtaining a layer of at least one printing particle on the dial blank 10, 20. It should be noted that such a transition has the advantage of being performed very quickly, typically less than one second.

More specifically, in this production sub-step 49, and in particular during the execution of the application phase 50, the control unit 2 executes said at least one control command comprising data 9b describing the layers constituting said reference digital graphical representation 9a to be reproduced. Subsequently, the printing device 3 applies the first layer formed by at least one type of particles directly onto the dial blank 10, 20 according to the at least one control command executed. The first layer formed by the at least one particle is then subjected to a fixing sub-stage of the treatment stage 51, during which it is exposed to an air flow, in particular a hot air flow, and/or to optical radiation, in particular ultraviolet radiation or infrared radiation. Subsequently, the printing device 3 can apply the second layer formed by at least one type of particles to the first layer formed by at least one type of printing particles already present on the dial blank 10, 20, according to the at least one control command executed. The second layer formed by at least one type of particles is also subjected to the fixing sub-phase of the processing phase 51 in order to transform it into a second layer formed by at least one type of printing particles on the first layer formed by at least one type of printing particles on the dial blank 10, 20.

The three-dimensional element 30 is thus produced by superimposing on a specific area of the dial blank 10, 20 a plurality of layers formed by at least one type of printed particles, such as the arabic numerals in fig. 6 and 7 or the graduations in fig. 8, in order to obtain numerals and graduations with a thickness exceeding 100 microns, so as to be visible to the naked eye of a person wearing a watch comprising a dial 11 obtained using the method according to the invention. In general, the superposition of three layers formed by at least one printing particle is sufficient to obtain a raised portion for the dial 11. It should be noted that, depending on the nature of the inks used, the method for manufacturing the dial 11 with the three-dimensional element 30 having a thickness of at least 100 microns can be carried out by superimposing only two layers formed by at least one type of printed particles. Fig. 9 shows a dial 11 comprising a more pronounced three-dimensional element 30, the thickness of which can be obtained by superimposing four or five layers of at least one printing particle.

The three-dimensional element 30 may here comprise a pattern or image sufficiently raised with respect to the flat surface of the dial blank 10, 20 so as to constitute a raised decoration visible to the naked eye to a person wearing a timepiece 40 comprising a dial 11 produced according to the method of the invention. Thus, as mentioned above, the three-dimensional element 30 can be in particular a number representing an hour (for example an arabic or roman numeral), a scale or a pattern extending over a large part or a portion of the dial blank 10, 20.

It should be noted that the thickness of each layer formed by the at least one viscoelastic polymeric fluid may be in the range 10 to 150 microns, and is preferably equal to 100 microns.

Furthermore, it should be noted that once the three-dimensional element 30 has been manufactured, the method can provide the potential step of depositing at least one colourless/translucent/transparent ink layer on the whole dial 11 or on specific portions of the dial 11, in order to obtain a matt or shiny effect.

The method then comprises step 52: before making the adjustment until timepiece 40 is armed, dial 11 is removed from the support element of system 1.

The invention also relates to a computer program comprising program code instructions for executing the steps of the method when said program is executed by the control unit 2.