CH720375A2 - Timepiece with localized illumination - Google Patents

Abstract

The invention relates to a timepiece (1) comprising at least one covering element (2a) comprising a visible face (20a) formed of a transparent or translucent body comprising an autonomous lighting device, said decorative element covering (2a) being formed by an assembly (9a) of a plurality of superimposed layers (10, 11, 12, 13) connected together, each comprising one or more following functional elements of said lighting device: – at least one light source (4) capable of generating light in the visible face (20a) of the covering element (2a); – an autonomous power supply unit, and – a control unit (7) configured to manage the operation of the light source (4); said at least one light source (4) being configured to produce light localized on a point or quasi-point area (28) of the visible face (20a) of the covering element (2a), so as to produce a illumination localized on said covering element (2a).

Description

Technical field of the invention

[0001] The present invention relates to a timepiece with localized illumination comprising at least one covering element provided with a completely autonomous lighting device. More precisely, the present invention relates to a timepiece presenting original localized effects of light, for a functional, aesthetic and/or playful purpose.

Technology background

[0002] Creating timepieces such as wristwatches with an improved aesthetic appearance is a constant concern among watch manufacturers and in particular among those responsible for designing the various trim elements. It would be too long to list here all the solutions that have been considered to give a timepiece as neat and aesthetic an appearance as possible. As an example only, we can cite the technique of guilloché dials, the shape and/or color of the dial appliques or hands or even the addition of precious or semi-precious stones.

[0003] In this context, we understand that there is a need to find a solution, which does not present the disadvantages of the prior art and which aims to offer customers watches whose appearance is both aesthetic, surprising and functional.

Summary of the invention

[0004] The invention overcomes the drawbacks of the prior art by providing a timepiece with localized illumination at several points of the part, simple to produce and presenting original localized effects of light, for a functional, aesthetic and /or playful.

[0005] For this purpose, the present invention relates to a timepiece comprising at least one trim element comprising a visible face formed of a transparent or translucent body comprising an autonomous lighting device, said trim element being formed by an assembly of a plurality of superimposed layers connected together each comprising one or more following functional elements of said lighting device: – at least one light source capable of generating light in the visible face of the covering element ; – an autonomous electrical power supply unit, and – a control unit configured to manage the operation of the light source; said at least one light source being configured to produce localized light on a point or quasi-point area of the visible face of the covering element, so as to produce localized illumination on said covering element.

[0006] In other embodiments: – said assembly consists of a first layer forming the visible face comprising said at least one point light source; – each point light source is an electroluminescent element; – each point light source is a quantum box or dot; – said assembly comprises, in addition to the first layer, the following successive layers: • a second layer comprising a photovoltaic module constituting the autonomous electrical power supply unit; • a third layer comprising an electrical energy accumulator constituting the autonomous electrical power supply unit; • a fourth layer forming a hidden face of the covering element comprising the control unit; – said assembly comprises, in addition to the first layer, the following successive layers: • a second layer comprising a photovoltaic module constituting the autonomous electrical power supply unit, and • a third layer forming a hidden face of the covering element comprising the control unit and an electrical energy accumulator constituting the autonomous electrical power supply unit; – the functional elements are printed on substrates constituting the layers of the assembly forming said at least one covering element; – the first layer is rigid relative to the other layers included in the assembly which are flexible; – the point light sources are configured such that each point or quasi-point zone of the visible face likely to be illuminated is able to be illuminated by a single monochrome point light source; – the point light sources are configured in such a way that each point or quasi-point zone of the visible face likely to be illuminated is capable of being illuminated by several point light sources presenting distinct light colors; – said at least one trim element is chosen by one of the following elements: a back, a middle, a dial, a bracelet strand, a bezel, a flange, a push button, a winding crown and/or a winding crown fitted with a cap.

Brief description of the figures

[0007] The aims, advantages and characteristics of the timepiece according to the invention will appear better in the following description on the basis of at least one non-limiting embodiment illustrated by the drawings in which: – Figure 1 is a sectional view of a case of a timepiece equipped with a covering element such as a dial provided with an autonomous lighting device according to embodiments of the invention; – Figure 2 represents an exploded view of a first variant of the assembly of four superimposed layers forming said dial provided with the autonomous lighting device, said layers each comprising one or more constituent elements of the lighting device according to the modes of realization of the invention; – Figure 3 represents a schematic view of this first variant of the assembly of layers forming the dial provided with the autonomous lighting device according to the embodiments of the invention; – Figure 4 represents an exploded view of a second variant of the assembly comprising three superimposed layers forming said dial provided with the autonomous lighting device, said layers each comprising one or more constituent elements of the lighting device according to the modes of realization of the invention; – Figure 5 represents a schematic view of this second variant of this assembly of layers forming the dial provided with the autonomous lighting device, according to the embodiments of the invention, and – Figures 6 to 8 are top views of timepieces each comprising a covering element such as a bezel comprising a plurality of light sources, according to the embodiments of the invention.

Detailed description of the invention

[0008] The present invention proceeds from the general inventive idea which consists of housing one or more point light sources 4 in at least one covering element 2a, 2b, 2c of a timepiece 1. This element of covering 2a, 2b, 2c comprises a visible face 20a formed of a transparent or translucent body which is also called "visible part" or "visible upper part", and also includes a hidden face 20b otherwise called "hidden part" or " hidden lower part of this element 2a, 2b, 2c. In this configuration, the light produced by each light source 4 is located in a point or quasi-point zone 28 of this visible face 20a of the covering element 2a, 2b, 2c concerned, so as to produce localized illumination on said covering element 2a, 2b, 2c. We thus provide a timepiece 1 with localized illumination at several points of the part 1, simple to produce and presenting original localized light effects, for a functional, aesthetic and/or playful purpose. When the illumination is switched on, the localized light zones 28 on the covering element 2a, 2b, 2c transmit a more or less strong and diffuse light depending on the construction and the light power installed, thus creating functional and/or effects. or aesthetic, in contrast with the unlit parts of the covering element 2a, 2b, 2c.

[0009] It will be noted that such illumination can have a more or less diffuse, discreet, soft and pleasant appearance, these characteristics being able to be varied practically infinitely depending on the desired aesthetic rendering, which increases the final aesthetic quality of the timepiece 1.

[0010] Such a timepiece 1 according to the invention can be for example an electronic, electromechanical and/or mechanical watch, and in particular a sports watch or a so-called “luxury” watch.

[0011] In the context of this invention, a “point or quasi-point zone” includes any zone located on/in the visible face 20a of the body of the covering element 2a, 2b, 2c concerned, and has dimensions such that it is perceived as distinct from neighboring areas by a human eye.

[0012] In this timepiece, the trim elements 2a, 2b, 2c correspond to all of the constituent parts of the timepiece 1 surrounding a movement 31, thus giving this piece 1 its aesthetic and its style, also allowing the indication of all its functions. More precisely and with reference to Figures 1 and 6, these constituent parts considered here include in a non-exhaustive and non-limiting manner: a back 24, a middle part 23, a dial 32, bracelet strands 29, a bezel 26, a button- pusher, flange, hand, winding crown and/or crown cap

[0013] In the following description, all the parts of the timepiece 1 which are well known to those skilled in the art will only be explained in a simplified manner.

[0014] Figure 1 is a sectional view of a middle part delimiting with a bottom 24 and a dial 32, an interior volume of a box 22 of this timepiece 1. The box 22 is closed on the top by a mirror 25. For the purposes of this description, we will imagine that the timepiece 1 is a mechanical watch and that its movement 31 is arranged in the box 22. In this configuration at least one covering element 2a, 2b , 2c of this part 1 comprises an autonomous lighting device 3 (visible in Figures 1, 2 and 4) provided with at least one point light source 4. The light produced by this said at least one source 4 illuminates an area punctual or quasi-punctual 28 of the covering element 2a, 2b, 2c, to be illuminated, namely the dial 32 in the particular embodiment of Figure 1 or the bezel 26 in an embodiment of Figures 6 to 8. To do this, the light coming from each point light source 4 can for example be collimated or focused towards the point or quasi-point zone 28 in question, by any known means of collimation or focusing.

It will be noted that in the embodiment of the invention described, the watch movement 31 is a mechanical movement. In a variant, this movement 31 can be an electronic movement or even an electromechanical movement. Here we can speak of a mechanical watch when its movement is mechanical and of electromechanical and electronic watches when they comprise electromechanical and electronic movements respectively.

[0016] In this configuration, the watch movement 31 drives, in a manner known to those skilled in the art, hands 27 comprising an hour hand, a minute hand and possibly a second hand. For this purpose, the dial 32, 2a, 2b has a through hole receiving the axis of the hands.

[0017] In the particular embodiment of Figure 1, the covering element 2a, 2b here a dial 32 therefore comprises the autonomous lighting device 3. This lighting device 3 comprises its own power supply means electric as we will see later. Such a lighting device 3 is said to be autonomous in particular with respect to the movement 31 of the timepiece 1 and in particular to the energy source of this movement 31, for example when this energy source is an electrical supply as in an electromechanical movement or even an electronic movement. Under these conditions, we understand that the energy used by this lighting device 3 is not to the detriment of the autonomy of the movement 31.

This lighting device 3 comprises the following functional elements: said at least one point light source 4 also called point light source, an electrical power supply unit 21 and a control unit 7.

[0019] In this lighting device 3, the electrical power unit 21 comprises an electrical energy accumulator 6 and a photovoltaic module 5 also called solar cells. This photovoltaic module 5 is connected to the electrical energy accumulator 6 via connection elements referenced 17b and 18 in Figures 3 and 5. This photovoltaic module 5 may comprise one or more elementary cells of the heterojunction or multijunction type, connected in parallel or in series. The photovoltaic cells of this module 5 can be made, in a manner known to those skilled in the art, from semiconductor materials based on copper, indium, gallium and selenium, based on cadmium telluride , based on monocrystalline gallium arsenide or based on monocrystalline or polycrystalline silicon, or with perovskites. It should be noted that these examples are non-limiting and that those skilled in the art will be able to find the type of photovoltaic cells suitable for the invention.

[0020] In this lighting device 3, the control unit 7, also called a microcontroller, comprises an electronic circuit 8 comprising hardware resources, in particular at least one processor cooperating with memory elements as well as address buses, data and control. This control unit 7 comprises in its memory elements an algorithm for managing the illumination of said at least one light source 4. Such an algorithm is executed by the processor of this control unit 7 taking into account in particular data coming from event sensors included in the lighting device 3 in order to ensure management of the operation of said at least one light source 4.

[0021] It will be noted that such data can for example provide information relating to events detected by these sensors, said events being capable of contributing to the operation of said at least one light source 4. These events can include, in a non-limiting manner and non-exhaustive: the detection of a particular level of brightness in the environment of the timepiece 1, the detection of a particular sound element or a particular sound level, the detection of a particular visual object, the detection of a movement made by this part 1, etc.

[0022] In this context, the event sensor of this autonomous lighting device 3, comprises in particular and in a non-limiting and non-exhaustive manner: – a brightness sensor making it possible to detect the ambient brightness level; – a movement sensor such as a gyroscopic and/or inertial sensor in the form of an electronic component of the gyroscopic and/or inertial electromechanical microsystems circuit type; – a microphone-type sound sensor, and/or – an optical sensor such as a photographic sensor.

Furthermore, it will be noted that this control unit 7 is capable of managing/controlling the operation of the light sources 4 simultaneously and/or in sequence. In addition, each light source 4 is managed/controlled by this control unit separately. In this context, the management of the operation of each light source 4 can consist in a non-limiting and non-exhaustive manner of carrying out the following operations: a sequential switching on or off (the), a simultaneous switching on or off (e) of two or more light sources 4, a flashing of one or more light sources 4, a definition of a flashing frequency for each light source 4, a flashing duration for each light source 4, an on or off duration extinction for each light source 4, etc.

Such a control unit 7 can also include in its memory elements an algorithm for managing the electrical energy accumulator 6, in particular the management of its recharging by the photovoltaic module 5 and the management of electrical consumption by said light source 4.

[0025] With reference to Figures 2 to 8 and as we mentioned previously, the autonomous lighting device 3 is therefore included in the covering element 2a, 2b, 2c. In this configuration, the functional elements of this lighting device 3, namely the light source 4, the electrical energy accumulator 6, the photovoltaic module 5 and the control unit 7, are included in one or more layers 10 , 11, 12, 13, 14 forming the covering element 2a, 2b, 2c.

In other words, the body of this covering element 2a, 2b, 2c is formed by an assembly 9a, 9b of a plurality of superimposed layers 10, 11, 12, 13, 14 connected together and each comprising a or several functional elements of the lighting device 3.

[0027] In this assembly 9a, 9b, the layers 10, 11, 12, 13, 14 are connected together by a connecting element such as an adhesive substance so as to unify them in order to obtain a monolithic assembly 9a, 9b forming thus a one-piece covering element 2a, 2b. Such layers 10, 11, 12, 13, 14 are superimposed in the assembly 9a, 9b, being arranged one above the other in a defined order.

[0028] Thus such a one-piece covering element 2a, 2b, 2c (e.g.: dial, bezel), also has the advantage of being able to be removably mounted on a timepiece box 1 in more to facilitate its integration in or on such a box.

More precisely, in first and second variants, this assembly 9a, 9b comprises a first layer 10 forming/constituting a visible face 20a of the covering element 2a, 2b, 2c. Such a first layer 10 is formed by a transparent or translucent or at least partially transparent or at least partially translucent substrate which is rigid or semi-rigid. Such a substrate is made of a material having a transmittance to light radiation such as solar radiation, in particular ultraviolet radiation, also called UVT (for “Ultra-Violet Transmission”) which is between 65 and 95 percent. This transmittance is preferably 85 percent. Such material can be transparent or translucent. This material can be, in a non-limiting and non-exhaustive manner, a polymer, glass or even ceramic.

[0030] In this context, we understand that this substrate is configured so that: – the light produced by said at least one light source 4 can escape towards the outside of the covering element 2a, 2b, 2c and therefore from the timepiece 1, and – the light coming from the environment of the timepiece 1 can penetrate into the covering element 2a, 2b, 2c in the direction of the photovoltaic module 5 of the lighting device 3, this light comprising solar radiation when it is of natural origin.

In other words, this transparent or translucent substrate is configured to be crossed by light radiation such as solar radiation capable of powering the photovoltaic module 5 so that the latter can convert the solar energy coming from this radiation into energy electric.

Such a first layer 10 comprises said at least one light source 4 of the lighting device 3 of the covering element 2a, 2b, 2c.

[0033] In this device 3, any type of point light source 4, such as an electroluminescent element can be used, for example: – an electroluminescent capacitor better known by the acronym LEC for “Light-Emitting Capacitor”; – a light-emitting diode such as LED (for “Light-Emitting Diode”), OLED (for “Organic Light-Emitting Diode”), AMOLED (for “Active-Matrix Organic Light-Emitting Diode”) or even QLED (for “Quantum”) Light-emitting diode” – any electroluminescent material activated by a local electric field; – any electroluminescent material activated by an electric current;

This said at least one light source 4 is arranged in a particular manner on or in the substrate forming this first layer 10. Such an arrangement of the light source 4 is configured to ensure illumination of all or part of the visible face 20a of the covering element 2a, 2b, 2c. For example, when this covering element 2a, 2b, 2c is a dial 32 as in Figure 1 or even a bezel 26 as in Figures 6 to 8, it may be lighting of all or part of the visible face 20a of this dial 32, 2a, 2b or the bezel 26, 2c, or even lighting of at least one graphic representation present in or on the lower surface of this visible face 20a such that: - a reference element (or display) such as for example a number, an index, a line or even a point contributing to participating with/without the hands in the display of horological information/quantity or information/magnitude physics measured by a sensor or the like included in the movement 31; – an inscription, a pattern, a text, a logo, etc.

This lighting can be backlighting or semi-direct type lighting when the light source 4 is arranged in a cavity defined in the substrate. More precisely, this cavity can be a blind opening made in the lower surface of this substrate. In this configuration, when the bottom of this cavity includes a graphic representation, the light radiation, or the light, produced by this light source 4 can escape towards the outside of the dial 2a via the visible face 20a of this dial 2a, thus allowing the visualization of at least one graphic representation in the dark. In particular, the light radiation thus escaping from the visible face 20a, draws the outline of this graphic representation. In this context, this graphic representation included in or on the upper surface or even on the lower surface of the substrate forming the first layer 10, is preferably opaque or non-translucent or non-transparent.

This lighting can be direct lighting when the light source 4 is arranged in a cavity defined in the substrate. This cavity can be a blind opening made in the lower surface of this substrate and the bottom of which is devoid of any graphic representation. In this configuration, the light radiation, or light, produced by this light source 4 can escape through the bottom of this cavity towards the outside of the dial 2a and therefore through the visible face 20a of this dial 2a.

This lighting can also be direct lighting when the light source 4 is arranged in a through opening made in the substrate. In this context, this opening then extends into the thickness of the substrate of this first layer 10, opening at its two ends respectively into the upper and lower surfaces of this substrate. In this configuration, all or part of the light source 4 can project from the upper surface of this substrate and therefore from the visible face 20a of this covering element 2a, 2a, 2c.

Such lighting can also be indirect lighting when said at least one light source 4 is coupled to at least one waveguide. This wave guide, also called a light guide, makes it possible to bring the light from the point where it is injected into the guide to the level of the point or quasi-point zone 28 of the covering element 2a, 2b, 2c to illuminate. The light guide is for example an optical fiber which makes it possible to bypass any obstacles which may arise in the substrate between the electroluminescent element and the point or quasi-point zone 28 considered of the substrate through which the light will escape. In this variant embodiment, it is therefore the light which is brought, via the waveguide, from the electroluminescent element to the point or quasi-point zone 28 of the substrate to be illuminated.

[0039] In such a configuration, a first end of the waveguide is coupled with the light source 4 and a second end of this guide can be arranged in: – a cavity which can be a blind opening made in the lower surface of the substrate of this first layer 10, or – a through opening extending into the thickness of the substrate of the first layer 10 and opening at its two ends respectively into the upper and lower surfaces of this substrate and therefore of the first layer 10. Thus this second end can project from the upper surface of this substrate and therefore from the visible face 20a of the covering element 2a, 2b, 2c.

[0040] In this context, indirect lighting can be achieved by a single light source 4 included on the lower surface of the substrate of this first layer 10 while being coupled to several waveguides whose second ends are arranged in: – cavities each emitting light radiation, coming from this light source 4, this radiation escaping towards the outside of the covering element 2a, 2b, 2c via its visible face 20a, thus authorizing the visualization of at least a graphic representation located at the bottom of this cavity in particular in the dark, and/or - through openings projecting or not from the upper surface of the substrate of this first layer 10 in order to form graphic representations such as elements markers, each emitting light radiation, coming from this light source 4.

[0041] In the substrate of this first layer 10, the light source 4 is applied/fixed on the lower surface of this substrate, in said cavity or on an internal wall of the through opening mentioned above, by printing or evaporation .

[0042] In a particular embodiment of the invention, electroluminescent elements are used, each emitting ultraviolet, violet, blue, white or infrared light in combination with the substrate of the first layer 10 forming the visible face 20a of the covering element 2a, 2b, 2c and comprising a material at least partially transparent or translucent, loaded with fluorescent and/or phosphorescent particles. This substrate of the first layer 10 is loaded at the place or places where it is desired for the light to escape from the interior or the lower face of the substrate. In this way, the fluorescent and/or phosphorescent particles absorb the radiation emitted by each electroluminescent element and re-emit homogeneous visible light. Depending on the type of particles chosen, fluorescent and/or phosphorescent, the luminous effect ceases immediately after the light source 4 is extinguished or, on the contrary, continues through the afterglow effect. As a variant not shown in the figures, the point light sources can be quantum boxes or dots (called respectively “quantum box” or “quantum dot” in English).

[0043] In a particular embodiment of the invention, each point light source 4 is a monochrome light source, and each point or quasi-point zone 28 of the substrate of the first layer 10 capable of being illuminated, the is then by a single monochrome point light source 4. In another embodiment of the invention, the point light sources 4 are configured to present distinct light colors, and each point or quasi-point zone 28 of the substrate, capable of being illuminated, is then illuminated by several of these 4 point light sources. Note in another embodiment that each light source 4 can vary between different colors.

Furthermore, it will be noted that the lower surface of this first layer 10 can be self-adhesive in order to participate in its assembly with the second layer 11.

[0045] In the assembly 9a, 9b forming the covering element 2a, 2b, 2c, the second layer 11 comprises a substrate comprising the photovoltaic module 5. This substrate is preferably flexible or flexible. Such a substrate can be a film on which this photovoltaic module 5 is placed. For example, this substrate can be made of a material belonging to the polymer family. Such a photovoltaic module 5 preferably extends over the entire so-called active zone of an upper surface of this substrate of the second layer 11. This active zone is a portion of this upper surface of the substrate which is capable of receiving the light coming from the lower surface of the first layer 10 of the covering element 2a, 2b, 2c. This light which has passed through all or part of the first layer 10, comes from the external environment of the covering element 2a, 2b, 2c, and therefore from the timepiece 1, here mainly from solar radiation when it is of natural origin.

[0046] It will be noted that the photovoltaic module 5 is applied to the upper surface of this substrate using inkjet printing processes or even by screen printing or using a thermal evaporation printing process. We will also speak here of a second layer 11 comprising a printed photovoltaic module 5. In particular, a photovoltaic module 5 printed on the substrate of the second layer 11.

[0047] Furthermore, it will be noted that once the photovoltaic module 5 has been applied to the substrate, a layer of a self-adhesive or adhesive substance can be deposited on all or part of the upper surface and/or the surface lower part of this substrate. Under these conditions, the second layer 11 can be a self-adhesive layer which helps to facilitate its assembly/mounting/gluing with the other layers, in particular with the first layer 10 and/or a third layer 12 of this assembly 9a, 9b.

[0048] In this first variant, the assembly 9a comprises this third layer 12 also comprising a preferably flexible or flexible substrate, comprising the electrical energy accumulator 6 of the autonomous lighting device 3. This substrate can be a film on which the accumulator 6 is included. Such a substrate can be made of a material belonging to the polymer family.

This accumulator 6 can be a lithium battery or even a semiconductor battery. Such an accumulator 6 is applied to an upper surface of this substrate using processes known from the state of the art such as: – printing processes on a flexible polymer substrate when it is for example a battery lithium, or – three-dimensional printing processes when it concerns for example a solid-state battery such as a solid-state lithium-metal battery.

[0050] We will also speak here of a third layer 12 comprising a printed electrical energy accumulator 6. In particular, an electrical energy accumulator 6 printed on the substrate of the third layer 12.

[0051] Thus, such methods make it possible to obtain a third layer 12 comprising this accumulator 6 which is flexible and ultrathin.

[0052] Furthermore, it will be noted that once the accumulator 5 is applied to the substrate, a layer of a self-adhesive or adhesive substance can be deposited on all or part of the upper surface and/or the lower surface of this substrate. Under these conditions, the third layer 12 can be a self-adhesive layer which helps to facilitate its assembly/mounting/gluing with the other layers, in particular with the second layer 11 and/or a fourth layer 13 of this assembly 9a.

It will be noted that this accumulator 6 serves to store the electrical energy produced by the photovoltaic module 5 and to restore it on demand to power said at least one light source 4.

[0054] In the first variant illustrated in Figures 1, 2 and 3, this assembly 9a comprises this fourth layer 13 forming the hidden face 20b of the covering element 2a, 2c. This fourth layer 13 is formed by a preferably flexible or flexible substrate, comprising the control unit. Such a substrate can for example be a flexible PCB on which this control unit 7 is arranged, in particular on the upper surface of this PCB and therefore of the substrate. In this context, the construction of the control unit 7 on this upper surface of the substrate can be carried out using three-dimensional printing processes or even polymer printing processes.

[0055] In the second variant illustrated in Figures 4 and 5, the assembly 9b forming the covering element 2b, 2c, comprises three layers 10, 11, 14, connected together. It will be noted that this second variant differs from the first variant in that it therefore comprises three layers 10, 11, 14 instead of four layers 10, 11, 12, 13, as in the first variant. In this second variant, the electrical energy accumulator 6 of the autonomous lighting device 3 is now included in the third and last layer 14 of this assembly 9b with the control unit 7.

[0056] Such a third layer 14 forming the hidden face of the covering element 2b, is made up of a preferably flexible or flexible substrate, on which are built, preferably on the upper surface of this substrate, the accumulator 6 and the electronic circuit 8 constituting the control unit 7. Such construction of the accumulator 6 and the control unit 7 on this upper surface of the substrate can be carried out using three-dimensional printing processes or still polymer printing processes. It will be noted that such a substrate can be, for example, a flexible PCB.

[0057] In summary, in this second variant, the assembly 9b then comprises: – a first layer 10 forming the visible face 20a of the covering element 2b, 2c including said at least one light source 4 of the lighting device 3; – a second layer 11 including the photovoltaic module 5, and – the third layer 14 forming the hidden face 20b of the covering element 2b, 2c including the accumulator 6 and the control unit 7.

It will be noted that in this second variant, the first and second layers 10, 11 are similar to those of the first variant of the assembly 9a.

[0059] Furthermore, with reference to Figures 3 and 5, the electronic circuit 8 of the control unit 7 comprises first connection elements 15a which are connected to connection elements 16 of said at least one light source 4 for managing the operation of this light source 4. This electronic circuit 8 also comprises second connection elements 15b connected to first connection elements 17a of the accumulator 6. This accumulator 6 also comprises second connection elements 17b connected to connection elements 18 of the photovoltaic module 5.

[0060] Furthermore, it will be noted that the event sensors of the lighting device 3, mentioned previously, are preferably arranged in the first layer 10 and/or the last layer 13, 14 of the assembly 9a, 9b, being connected to the control unit 7 of this device 3.

[0061] Furthermore, it will be noted in a variant not shown that the covering element may comprise an assembly 9a, 9b whose first layer 10 comprises a substrate of transparent or translucent ceramic material comprising one or more inserts of opaque material. It is also possible to provide a substrate made of ceramic material mixing several colors of ceramic during injection, in particular via bi-injection processes, at least one of these multiple colors being partially transparent or translucent in order to allow light to pass through to predetermined locations. and produced by the bi-injection process.

[0062] According to another variant not shown, the covering element 2a, 2b, 2c and in particular its first layer 10 may comprise several point light sources 4 which can be combined with one or more graphic representations inscribed in the ceramic material substrate of this layer 10, to be illuminated: – either by variation in thickness of the ceramic by mechanical or laser engraving (for example a withdrawal of a few 10th or 100th of a millimeter in the ceramic); – either from an internal engraving method in the substrate, in particular by a laser engraving process; – either by variation in density of the ceramic; – either by an opaque or semi-transparent print inside or on the surface of the ceramic covering element; – either by physical vapor deposition PVD (for “Physical Vapor Deposition”) or other, structured inside or on the surface of the covering element, or – or by a combination of these methods.

[0063] Thus when the light emission of the point light sources 4 is activated, the normally invisible graphic representation appears by backlighting on the visible face of the covering element 2a, 2b, 2c.

[0064] Furthermore, it will be noted that the timepiece 1 according to the present invention can advantageously be used to provide various functional applications to a user of the timepiece 1. For this purpose, the ignition and the extinction of the point light sources 4, are configured so that the timepiece 1 presents, on the covering element 2a, 2b, 2c illuminated by the point light sources 4, at least one visual indication of a function specific to the timepiece 1 and/or relating to a measurement of an external parameter or a parameter concerning the user of the timepiece 1. Switching on and/or switching off the light sources punctual 4, can be controlled by the control unit 7 simultaneously and/or in sequence.

[0065] By way of example, with reference to Figure 6, a possible functional application is illustrated here for the timepiece 1 and this, when such a part 1 is an electronic or electromechanical watch, and the control unit 7 of its covering element 2c here the bezel 26, comprises a communication module capable of exchanging data with the movement of this timepiece 1. On a punctual or quasi-punctual zone 28 of this element d 2c here the bezel 26 of this part 1, localized illumination indicates the time, namely 1 p.m. in the example illustrated. The punctual or quasi-punctual zone 28 corresponds in fact to the position of a number or applique 30 on the dial 32 of part 1. The localized illumination allows in particular the reading of the time at night.

[0066] Another possible functional application for this same timepiece 1 is illustrated in Figure 7. On a first point or quasi-point zone 28a of the bezel 26 of this part 1, a first localized illumination indicates the time , namely 5 hours in the example illustrated. On a second point or quasi-point zone 28b of the bezel 26 of this part 1, a second localized illumination indicates the minutes, namely 40 minutes in the example illustrated. The second illumination (corresponding to the minutes) can be done simultaneously with the first illumination (corresponding to the hour). The colors of light on the first and second point or quasi-point zones 28a, 28b can be identical (in the case of sequential illuminations) or different (in the case of simultaneous illuminations). This last scenario allows the user of room 1 to be able to distinguish the hour from the minutes. The first and second localized illuminations make it possible to read the hours and minutes at night.

[0067] Another possible functional application for this timepiece illustrated in Figure 8. On one or more point or quasi-point zones 28 of the bezel 26 of this part 1, in this case on eight zones in the example shown, several localized illuminations indicate a countdown or luminous chronograph. The point or quasi-point zones 28 on the bezel can light up or turn off respectively as time passes.

[0068] In each of the embodiments illustrated in Figures 6 to 8, the first layer 10 of the covering element 2c here the bezel 26 typically comprises twelve electroluminescent elements making it possible to illuminate a punctual or quasi-punctual zone 28 on this bezel 26, these zones 28 becoming visible only when they are illuminated.

[0069] As an alternative to the embodiments illustrated in Figures 6 to 8, the punctual or quasi-punctual zones 28 of localized illumination can be provided on the periphery of the middle part 23 of this part 1, rather than on the bezel 26.

[0070] Another possible functional application for the timepiece according to the invention, similar to that of Figure 6 but not shown in the figures, consists of displaying the date via localized illumination on a point or quasi-point area 28 of the bezel of the timepiece. The punctual or quasi-punctual zone 28 corresponds in fact to the position of a number or applies 30 on the dial of the timepiece 1. For dates beyond “12”, the two digits of the day can be indicated in sequence, followed by the month (for example „2“ then „3“, then „1“ for January 23). A different light color can be used for day and month. The localized illumination allows the date to be read at night.

[0071] It goes without saying that the present invention is not limited to the embodiments which have just been described and that various simple modifications and variants can be envisaged by those skilled in the art without departing from the scope of the invention. as defined by the appended claims.

Claims (10)

1. Timepiece (1) comprising at least one covering element (2a, 2b, 2c) comprising a visible face (20a) formed of a transparent or translucent body comprising an independent lighting device (3), said covering element (2a, 2b, 2c) being formed by an assembly (9a, 9b) of a plurality of superimposed layers (10, 11, 12, 13, 14) connected together each comprising one or more functional elements following of said lighting device (3): – at least one light source (4) capable of generating light in the visible face (20a) of the covering element (2a, 2b, 2c); – an autonomous power supply unit (21), and – a control unit (7) configured to manage the operation of the light source (4); said at least one light source (4) being configured to produce light localized on a point or quasi-point area (28) of the visible face (20a) of the covering element (2a, 2b, 2c), of so as to produce localized illumination on said covering element (2a, 2b, 2c). 2. Timepiece (1) according to the preceding claim, characterized in that said assembly (9a, 9b) consists of a first layer (10) forming the visible face (20a) comprising said at least one point light source (4). 3. Timepiece (1) according to any one of the preceding claims, characterized in that each point light source (4) is: – an electroluminescent element; – a quantum box or dot. 4. Timepiece (1) according to any one of the preceding claims, characterized in that said assembly (9a) comprises, in addition to the first layer (10), the following successive layers: – a second layer (11) comprising a photovoltaic module constituting the autonomous power supply unit (21); – a third layer (12) comprising an electrical energy accumulator (6) constituting the autonomous electrical power supply unit (21); – a fourth layer forming a hidden face (20b) of the covering element (2a, 2c) comprising the control unit (7). 5. Timepiece according to any one of claims 1 to 3, characterized in that said assembly (9b) comprises, in addition to the first layer (10), the following successive layers: – a second layer (11) comprising a photovoltaic module constituting the autonomous power supply unit (21), and – a third layer (14) forming a hidden face (20b) of the covering element (2b, 2c) comprising the control unit (7) and an electrical energy accumulator (6) constituting the unit d autonomous power supply (21). 6. Timepiece (1) according to any one of the preceding claims, characterized in that the functional elements are printed on substrates constituting the layers (10, 11, 12, 13, 14) of the assembly (9a , 9b) forming said at least one covering element (2a, 2b, 2c). 7. Timepiece (1) according to any one of the preceding claims, characterized in that the first layer (10) is rigid relative to the other layers (11, 12, 13, 14) included in the assembly (9a , 9b) which are flexible. 8. Timepiece (1) according to any one of the preceding claims, characterized in that the point light sources (4) are configured such that each point or quasi-point zone (28) of the visible face ( 20a) capable of being illuminated is capable of being illuminated by a single monochrome point light source (4). 9. Timepiece (1) according to any one of claims 1 to 7, characterized in that the point light sources (4) are configured such that each point or quasi-point zone (28) of the face visible (20a) capable of being illuminated is capable of being illuminated by several point light sources (4) presenting distinct light colors. 10. Timepiece (1) according to any one of the preceding claims, characterized in that said at least one covering element (2a, 2b, 2c) is chosen by one of the following elements: a base (24) , a middle part (23), a dial (32), a bracelet strand (30), a bezel (26), a flange, a push button, a winding crown and/or a winding crown provided with a cap.