Dial and watch comprising same

Abstract

One aspect of the utility model relates to a watch dial (2a, 2b) of a watch (1), the watch dial comprises a device (3) used for determining the position of at least one pointer (24a, 24b) of the watch (1), the watch dial (2a, 2b) comprises a visible surface (20a) and a hidden surface (20b), the watch dial (2a, 2b) is formed by a stack (9a, 9b) of thin layers (10, 11, 12, 13, 14) of materials extending between the two surfaces (20a, 20b), each layer (10, 11, 12, 13, 14) is provided with a plurality of through holes, and the through holes are formed on the two surfaces (20a, 20b). 14) comprises the following one or more functional elements included in the determination device (3):-at least one light detection element (23); -at least a first light source (4a) and at least a second light source (4b); -an independent energy supply unit (21) comprising a photovoltaic module (5); and-a control unit (7) for managing the operation of each light source (4a, 4b) and of the at least one light detection element (23).

Description

TECHNICAL FIELD

[0001] The utility model relates to a watch comprising a dial, said dial being equipped with a device for determining the position of at least one hand of said watch, such device being autonomous. BACKGROUND

[0002] The prior art documents describe mechanical and electromechanical watches with hands, in which the hour and minute hands displaying the current time are driven by a gear train of a mechanical movement of the watch. In this context, the operation of the mechanical movement can be disturbed by the impact of the watch, the presence of electromagnetic fields or other external disturbances. Thus, although the internal clock of the watch provides an accurate indication of the current time, the hour and minute hands provide a distorted indication of the current time due to the influence of the external disturbances on the watch. It can therefore be necessary to resynchronize the position of the hour and minute hands.

[0003] In this context, it will be understood that there is a need to find a solution to overcome the drawbacks of the prior art. SUMMARY

[0004] The object of the utility model is to overcome these drawbacks by proposing a watch equipped with a dial comprising a device for determining the position of at least one hand, said device being autonomous and whose efficiency remains constant over time.

[0005] One aspect of the utility model relates to a watch dial comprising a device for determining the position of at least one hand of said watch, such dial comprising a visible face and a hidden face, said dial being formed from a stack of thin layers of material extending between these two faces, each of said layers containing one or more functional elements included in said determining device:

[0006] - at least one light detection element;

[0007] - at least a first light source and at least a second light source;

[0008] - an independent energy supply unit comprising a photovoltaic module; and

[0009] - a control unit for managing the operation of each light source and of said at least one light detection element.

[0010] In other embodiments:

[0011] - the dial comprises a through hole configured to receive a shaft intended to carry at least one hand of said watch;

[0012] - the stack of thin layers of material comprises a first layer equipped with the visible face of the dial and comprising said at least one light detection element and the first and second light sources;

[0013] - the stack of thin layers comprises a second layer comprising a photovoltaic module;

[0014] - the at least one first light source and the at least one light detection element are arranged so that a light beam emitted by the at least one first light source is reflected by the at least one pointer towards the at least one light detection element;

[0015] - the at least one first light source is configured to emit a light beam towards a reflective area of the at least one pointer, the reflective area being configured to reflect the light beam towards the at least one light detection element;

[0016] - the reflective area comprises a tilted reflective surface formed in a lower surface of the at least one pointer;

[0017] - the reflective area comprises a diffraction grating formed in a lower surface of the at least one pointer, the grating being configured to reflect a light beam towards the at least one light detection element;

[0018] - the at least one first light source is a vertical-cavity surface-emitting laser source;

[0019] - the at least one second light source is able to generate visual information as a function of the determined position of the at least one pointer;

[0020] - the first layer is configured so that the light radiation, in particular solar radiation, and the light radiation emitted by the first and second light sources can pass completely or partially from the first layer;

[0021] - the second layer comprises a substrate on which the photovoltaic module is printed;

[0022] - the photovoltaic module is arranged on an active area of the second layer, the area being configured to receive light rays originating from the first layer of the stack of thin layers;

[0023] - the stack of thin layers comprises a third layer comprising an electrical energy accumulator constituting an independent energy supply unit;

[0024] - the third layer comprises a substrate on which the electrical energy accumulator is printed;

[0025] - the stack of thin layers comprises a fourth layer forming a hidden face of the dial, the fourth layer comprising a control unit;

[0026] - the stack of thin layers comprises a third layer comprising a hidden face of the dial, the third layer comprising a control unit and an electrical energy accumulator constituting an independent energy supply unit;

[0027] - the first layer is rigid compared to the other layers of the stack, the other layers being flexible.

[0028] The present utility model discloses a watch comprising a dial of the type described above.

[0029] Advantageously, the watch comprises a mechanical or mechatronic timepiece movement. BRIEF DESCRIPTION OF DRAWINGS

[0030] The objects, advantages and features of the watch according to the present utility model will be more clearly presented in the following description, given on the basis of at least one non-limiting embodiment shown in the attached drawings, in which:

[0031] Figure 1 A perspective view of a watch comprising a dial equipped with autonomous means for determining the position of at least one hand of the watch is shown according to an embodiment of the present utility model;

[0032] Figure 2 An exploded view of a first alternative embodiment of a dial formed by a stack of four superimposed layers each comprising one or more constituent elements of the determining means is shown according to a first embodiment of the present utility model;

[0033] Figure 3 A first alternative embodiment of a dial equipped with autonomous determining means is shown schematically according to a first embodiment of the present utility model;

[0034] Figure 4 An exploded view of a second alternative embodiment of a dial formed by a stack of three superimposed layers each comprising one or more constituent elements of the determining means is shown according to a second embodiment of the present utility model;

[0035] Figure 5 A second alternative embodiment of a dial equipped with autonomous determining means is shown schematically according to a second embodiment of the present utility model; and

[0036] Figure 6 and 7 A dial of a watch according to an embodiment of the present utility model and a hand comprising a lower face equipped with a region reflecting a light beam emitted by a first light source towards a light detection element are shown schematically. DETAILED DESCRIPTION

[0037] Figure 1 A watch 1 is shown schematically comprising a case 19 with an intermediate piece to which a back cover and a crystal 22 are attached, a set of components forming a timepiece movement, and a dial 2a, 2b arranged between the timepiece movement and the crystal 22.

[0038] ​​​​​​In a manner known to those skilled in the art, a watch movement drives a set of hands, including an hour hand 24a, a minute hand 24b, and optionally a second hand. For this purpose, the dials 2a and 2b include through-holes for receiving shafts 25 of the hands. Each of the hands 24a and 24b has a reflective lower surface arranged facing the dials 2a and 2b. This lower surface is either wholly or partially reflective. Specifically, refer to... Figure 6 and 7 The lower surface includes a reflective region 26, which includes an inclined surface 27 or a diffraction grating 28.

[0039] These dials 2a and 2b further include the following two surfaces 20a and 20b:

[0040] - The so-called visible surface 20a, which is visible from the outside of the watch 1, is also referred to as the "visible portion" or "visible upper portion" of the dials 2a and 2b; and

[0041] - The so-called hidden surface 20b is arranged to face the watch movement in the periphery of the watch case 19 of the watch 1. The surface 20b is also referred to as the "hidden portion" or "hidden lower part" of the dials 2a and 2b.

[0042] In a non-restrictive and non-exhaustive manner, this visible surface 20a may include at least one graphical representation, for example:

[0043] - Reference (or display) elements, such as, for example, numbers, scales, lines or even dots, which, with or without the use of pointers, help to display a chronograph information / chronograph measurement or a physical information / physical measurement obtained by sensors, etc., contained in the movement;

[0044] - Inscriptions, patterns, texts, or symbols, etc.

[0045] The visible surface 20a and the hidden surface 20b are substantially flat and / or parallel to each other and / or opposite to each other. They are also connected to each other by the outer walls of the dials 2a, 2b.

[0046] It should also be noted that, in Figures 1 to 7 In the illustrated embodiments, dials 2a and 2b preferably have a circular shape. It should be understood that the present invention can also be implemented for dials 2a and 2b having other shapes, such as, for example, triangular or quadrilateral-like shapes.

[0047] In embodiments of this invention, the watch movement is a mechanical movement. Alternatively, the movement may be an electromechanical movement. In the following description, when the movement is mechanical, it will refer to a mechanical watch, and when the movement is electromechanical, it will refer to an electromechanical watch.

[0048] With reference to Figure 2 and Figure 4 This dial 2a, 2b comprises autonomous means 3 for determining the position of at least one hand 24a, 24b of the watch 1. Said determining means 3 comprise their own power supply mechanism, as will be described below. Such determining means 3 are considered autonomous, in particular with respect to the movement of the watch 1 and in particular with respect to the power source of said movement, for example when said power source is an electric power supply source as in an electromechanical movement. In these cases, it should be understood that the power used by said determining means 3 does not compromise the autonomy of the movement.

[0049] In the present document, the dial 2a, 2b can be removably installed in the watch 1, regardless of the type of watch 1. The only condition to be met is that the dial 2a, 2b comprises said determining means 3, so that said determining means are autonomous with respect to the movement of the watch 1. Said dial 2a, 2b is also called "autonomous dial" because it is not electrically connected to the movement of the watch 1. Said dial 2a, 2b can be considered as an independent component attached to the watch 1.

[0050] Said determining means 3 comprised in said dial 2a, 2b comprise: a light source 4a, 4b; an independent energy supply unit 21; at least one light detection element 23; and a control unit 7.

[0051] These light sources 4a, 4b comprise at least a first light source 4a for evaluating the position of at least one hand 24a, 24b of the watch 1 by cooperating with said at least one detection element 23. As will be seen below, said first light source 4a and detection element 23 are arranged below or above the visible face 20a of the dial 2a, 2b. In said configuration, said first light source 4a is then able to emit a light beam 29a towards a hand 24a, 24b moving above the visible face 20a, said hand 24a, 24b being able to reflect said light beam 29a into a light beam 29b towards the detection element 23. Such first light source 4a is preferably a Vertical Cavity Surface Emitting Laser or VCSEL.

[0052] These light sources 4a, 4b also comprise at least one second light source 4b, in particular for displaying visual information related to the determination of the position of the hands 24a, 24b. Said second light source 4b preferably comprises any light emitting element chosen from a non-exhaustive and non-limiting list comprising:

[0053] - a light emitting capacitor or LEC;

[0054] - a light emitting diode of LED (Light Emitting Diode), OLED (Organic Light Emitting Diode), AMOLED (Active-Matrix Organic Light Emitting Diode) or QLED (Quantum Light Emitting Diode) type;

[0055] - any luminescent material activated by a local electric field;

[0056] - any luminescent material activated by an electric current;

[0057] - any combination of these luminescent elements.

[0058] It should be noted that, in certain embodiments of the application, the second light source 4b can be a light source 4b capable of forming an area light source. This makes it possible to impart a predetermined shape to the area light source, typically, but not exhaustively or limitatively, a shape related to a graphic representation of a number, a letter, a logo or a text. It should also be noted that the second light source 4b can produce light in any color and / or in any direction.

[0059] In the determining device 3, the independent energy supply unit 21 comprises an electric energy accumulator 6 and a photovoltaic module 5 comprising at least one photovoltaic cell, also known as a solar cell. The photovoltaic module 5 is connected to the electric energy accumulator 6 via connection elements denoted by reference numerals 17b and 18 in Figure 3 and 5 The photovoltaic module 5 can comprise one or more unit cells of the heterojunction or multiple junction type, connected in parallel or in series. Each photovoltaic cell of the module 5 can be made of copper-based, indium-based, gallium-based and selenium-based semiconductor materials, cadmium telluride-based semiconductor materials, monocrystalline gallium arsenide-based semiconductor materials, monocrystalline or polycrystalline silicon-based semiconductor materials or perovskite semiconductor materials, in a manner known to those skilled in the art. It should be noted that these examples are not limitative and those skilled in the art will be able to find photovoltaic cell types suitable for use in the application.

[0060] In the determining device 3, the control unit 7, also known as a microcontroller, comprises an electronic circuit 8 comprising hardware resources, in particular at least one processor cooperating with storage elements and address, data and control buses. The control unit 7 is connected to the first and second light sources 4a, 4b, to the at least one light detection element 23 and to the independent energy supply unit 21. The storage elements of the control unit 7 comprise an algorithm for managing the position of at least one hand 24a, 24b of the watch. This algorithm is executed by the processor of the control unit 7, in particular taking into account the light intensity measurement data from the at least one light detection element 23 included in the determining device 3. This algorithm contributes to:

[0061] - determining the position,

[0062] - generating visual information from the determined position of the hand 24a, 24b,

[0063] - controlling the second light source 4b,

[0064] - enabling at least one function of the watch that requires the determination of the position of the pointer.

[0065] It should be noted that the determining device 3 can comprise at least one event sensor that allows the determination of the position of the pointers 24a, 24b to be improved and that also contributes to the display of the visual information. Thus, the sensor can generate data that will then be used by the algorithm. Such data can comprise information relating to events detected by the sensor that can contribute to the operation of the first and second light sources 4a, 4b. In a non-limiting and non-exhaustive manner, these events can comprise: the detection of a specific luminosity level in the environment of the watch 1; the detection of a specific sound element or a specific sound level; the detection of a specific visual object; or the detection of a movement made by a part of the body of the user in which the watch 1 is located, etc.

[0066] In the present document, in a particular and in a non-limiting and non-exhaustive manner, the event sensors of the autonomous determining device 3 can comprise:

[0067] - a luminosity sensor that detects the luminosity level of the environment;

[0068] - a movement sensor for sensing a movement made by a part of the body of the user comprising the watch 1, such as a gyroscope and / or an inertial sensor in the form of an electronic component of the gyroscope and / or inertial microsystem electromechanical circuit type;

[0069] - a microphone-type sound sensor; and / or

[0070] - a photographic-type optical sensor.

[0071] Moreover, when the determining device 3 comprises a plurality of second light sources 4b, their operation can be managed / controlled simultaneously and / or sequentially by the control unit 7. Moreover, each second light source 4b is managed / controlled individually by the control unit 7. In the present document, in a non-limiting and non-exhaustive manner, the management of the operation of each second light source 4b can comprise performing the following operations: sequential opening or closing, simultaneous opening or closing of two or more second light sources 4b; flashing one or more second light sources 4b; defining the flashing frequency of each second light source 4b, the flashing duration of each second light source 4b, or the opening or closing duration of each second light source 4b, etc.

[0072] The storage element of such control unit 7 can further comprise an algorithm for managing the electric energy accumulator 6, in particular for managing its recharge through the photovoltaic module 5 and for managing the power consumption of the light sources 4a, 4b and of the at least one light detection element 23.

[0073] As mentioned above, the autonomous determining device 3 is thus included in the dial 2a, 2b. In said configuration, the constituent elements of said determining device 3, i.e. the first and second light sources 4a, 4b, the electrical energy accumulator 6, the photovoltaic module 5, said at least one light detection element 23 and the control unit 7, are included in one or more layers 10, 11, 12, 13, 14 forming said dial 2a, 2b.

[0074] With reference to Figures 2 to 5 , said dial 2a, 2b is constituted or formed by a stack 9a, 9b of thin layers 10, 11, 12, 13 of material, which are joined together by a joining element, such as an adhesive substance, so as to make them integral, so as to obtain a stack 9a, 9b of integral layers, thus forming an integral dial 2a, 2b. Said joining element can also be a clip or a screw. Such layers 10, 11, 12, 13, 14 are stacked in a stack 9a, 9b, i.e. they are arranged one on top of the other in said dial 2a, 2b in a defined order. It should be noted that such a stack 9a, 9b of layers can also be referred to as an assembly of layers. In said stack 9a, 9b, the layers are substantially similar, having upper and lower surfaces of substantially the same area, thus contributing to form the peripheral wall of the dial 2a, 2b, which is not embossed.

[0075] It should be noted that these thin layers are layers each having a micrometric thickness. More specifically, each layer can have a thickness of between 1 and 100 micrometres, preferably 2 micrometres, or more preferably 3 micrometres. As regards the thickness of the dial 2a, 2b, it can be between 8 and 400 micrometres, preferably 6 micrometres, more preferably 12 micrometres, more preferably 100 micrometres, more preferably 200 micrometres or more preferably 300 micrometres.

[0076] In addition to facilitating integration in the watch case 19, such an integral dial 2a, 2b has the additional advantage of being able to be removably installed in the watch case 19 of the watch 1.

[0077] In the first alternative embodiment of said stack 9a illustrated in Figure 3 , said stack is constituted or formed by four successive thin layers 10, 11, 12, 13:

[0078] - a first layer 10 forming / constituting the visible face 20a of the dial 2a, which includes said at least one first light source 4a, said at least one second light source 4b and said at least one light detection element 23 of the determining device 3;

[0079] - a second layer 11 including the photovoltaic module 5;

[0080] - a third layer 12 including the electrical energy accumulator 6, also known as rechargeable battery; and

[0081] - a fourth layer 13 forming a hidden face 20b of the dial 2a, comprising the control unit 7.

[0082] In contrast to the second, third and fourth layers 11, 12, 13, which are preferably compliant or flexible, the first layer 10 of the stack 9a is preferably rigid or semi-rigid. It will be appreciated that such a first layer 10 contributes to the structural rigidity of the stack 9a and thus to the structural rigidity of the dial 2a.

[0083] In the stack 9a, the first, second, third and fourth layers 10, 11, 12 and 13 each comprise an upper face and a lower face.

[0084] The first layer 10 is formed of a transparent, translucent, at least partially transparent or at least partially translucent rigid or semi-rigid substrate. Such a substrate is made of a material having a transmittance of between 65% and 95% for solar radiation, in particular ultraviolet radiation, also known as UVT (i.e. “ultraviolet transmission”). The transmittance is preferably 85%. Such a material can be transparent or translucent. In a non-limiting and non-exhaustive manner, the material can be a polymer, glass or ceramic.

[0085] In the present text, it will be appreciated that the substrate is configured so that:

[0086] - the light produced by the first and second light sources 4a, 4b can escape to the outside of the dial 2a, 2b and thus to the outside of the watch 1; and

[0087] - the light from the environment of the watch 1 can penetrate the dial 2a, 2b towards the photovoltaic module 5 of the determining device 3, said light comprising solar radiation when it is natural light.

[0088] In other words, the transparent or translucent substrate is configured to allow the passage of said light capable of feeding the photovoltaic module 5 therethrough, so that the photovoltaic module can convert the solar energy from said radiation into electrical energy.

[0089] The first layer 10 further comprises the first and second light sources 4a, 4b arranged in the body of the substrate.

[0090] Such an arrangement of the at least one first light source 4a in / on the substrate is configured to ensure that the light beam 29a is emitted upwards towards the at least one pointer 24a, 24b. The first light source 4a can be arranged above or below the upper surface of the substrate forming the first layer 10. When arranged in the substrate, the first light source 4a is located in a blind cavity formed in the upper surface. In alternative embodiments, the first light source can be arranged in a blind cavity formed in the lower surface of the substrate, the substrate having the upper surface as its bottom. In the configuration, the light beam 29a that can be emitted by the first light source 4a then passes through the bottom before reaching the pointer 24a, 24b.

[0091] Such an arrangement of the at least one second light source 4b in the substrate is configured to ensure that all or part of the visible face 20a of the dial 2a is illuminated, in order to participate in the display of visual information, by reference to the determined position of the pointer 24a, 24b, for example, to illuminate a graphic representation related to the position, such as a pattern, a number or a letter; and / or to illuminate a graphic representation such as a reference element (or display), such as a number, a scale, a line, a dot; or to illuminate one or more pointers; or to illuminate even all or part of the surface of the visible face of the dial 2a. In alternative embodiments, the second light source 4b can have a predetermined shape, such as the shape of a number, a letter, a scale, a line, a dot, a logo or even a text.

[0092] When the second light source 4b is arranged in a cavity defined in the substrate, such illumination can be back lighting or semi-direct lighting. More particularly, the cavity can be a blind hole formed in the lower surface of the substrate. In this configuration, when the bottom of the cavity comprises a graphic representation, the luminous radiation or light produced by the second light source 4b can escape to the outside of the dial 2a via the visible face 20a of the dial 2a, thus allowing at least one graphic representation to be seen in the dark. In particular, the light radiation that escapes from the visible face 20a outlines the graphic representation. In this context, the graphic representation that is included in or on the upper surface or on the lower surface of the substrate forming the first layer 10 is preferably opaque, non-semi-transparent or non-transparent.

[0093] When the second light source 4b is arranged in a cavity defined in the substrate, such illumination can be direct lighting. The cavity can be a blind hole formed in the lower surface of the substrate, the bottom of the substrate not having any graphic representation. In the configuration, the luminous radiation or light produced by the second light source 4b can escape through the bottom of the cavity towards the outside of the dial 2a and thus through the visible face 20a of the dial 2a.

[0094] When the second light source 4b is arranged in a through-hole extending through the thickness of the substrate of the first layer 10, said illumination can also be direct illumination, said through-hole being open on the upper and lower surfaces of said substrate respectively at its two ends. In this configuration, all or part of the second light source 4b can protrude from the upper surface of said substrate and thus from the first layer 10 or from the visible face 20a of the dial 2a to form a graphic representation such as, for example, a scale, a number, a dot or a line, etc.

[0095] When said at least second light source 4b is coupled to at least one waveguide, this illumination can also be remote illumination. Such a waveguide, also called light guide, serves to bring light from its point of injection into the light guide to the substrate or to a region of the substrate close to the upper surface of said substrate (for example a cavity, a through-hole). Such a light guide can be an optical fiber which allows to bypass any obstacle that can arise in the substrate, for example between the electroluminescent element and the region of the substrate close to the upper surface of said substrate through which the light would escape. Thus, in said alternative embodiment, it is via the waveguide that the light is brought from the electroluminescent element to said region of the substrate to be illuminated.

[0096] In this configuration, the first end of the waveguide is coupled to the second light source 4b and the second end of said waveguide can be arranged in:

[0097] - a cavity which can be a blind hole formed in the lower surface of the substrate of said first layer 10; or

[0098] - a through-hole extending through the thickness of the substrate of the first layer 10, said through-hole being open on the upper and lower surfaces of said substrate respectively at its two ends, thus on the upper and lower surfaces of the first layer 10. Thus, said second end can protrude from the upper surface of the substrate or of said first layer 10 or from the visible face 20a of the dial 2a in order to form, for example, a graphic representation of said dial 2a such as, for example, a reference element such as a scale, a number, a dot or a line, etc.

[0099] In this document, indirect illumination can be achieved by a single second light source 4b comprised on the lower surface of the substrate of said first layer 10 by coupling to a plurality of waveguides whose second ends are arranged in:

[0100] - a cavity, each cavity emitting light radiation from said second light source 4b, said radiation escaping to the outside of the dial 2a via the visible face 20a, thus allowing at least one graphic representation to be seen in the dark. In this document, said graphic representation comprised in or on the visible face 20a of the dial 2a or in or on the upper surface of the substrate is preferably opaque; and / or

[0101] - vias, projecting or not from the upper surface of the substrate, so as to form reference elements, such as scales, lines or even points, and each via emits light radiation from the second light source 4b.

[0102] In the first layer 10, the second light source 4b is applied / fixed to the lower surface of the substrate of the first layer 10, in a cavity or on the inner wall of the aforementioned vias, by printing or evaporation.

[0103] In the first layer 10, the light detection element 23 is arranged in / on the substrate with respect to the first light source 4a so as to be able to receive the light beam 29b reflected by the pointer 24a, 24b, which has been emitted by the light source 4a. The detection element 23 can be arranged on or under the upper surface of the substrate forming the first layer 10. When arranged in the substrate, the detection element 23 is located in a blind cavity formed in the upper surface. In an alternative embodiment, the detection element can be arranged in a blind cavity formed in the lower surface of the substrate, which has the upper surface as its bottom. In this configuration, the light beam 29b reflected by the pointer then passes through the bottom before reaching the detection element 23.

[0104] It should also be noted that the lower surface of the first layer 10 can be self-adhesive, so that it can be assembled with the second layer 11.

[0105] In the stack 9a, the second layer 11 comprises a substrate comprising a photovoltaic module 5. This substrate is preferably flexible or compliant. The substrate of the second layer 11 can be a film on which the photovoltaic module 5 is arranged, or the substrate can be made of a material belonging to the polymer family.

[0106] In the second layer 11, the photovoltaic module 5 preferably extends over the entire so-called active area of the upper surface of the substrate. The active area is the part of the upper surface of the substrate that is able to receive light from the lower surface of the first layer 10 of the dial 2a. The light that has passed through all or part of the first layer 10 comes from the external environment of the dial 2a, and therefore from the external environment of the watch 1, in this case mainly from solar radiation when the light is natural light.

[0107] It should be noted that the photovoltaic module 5 is applied to the upper surface of the substrate using an inkjet or screen printing process or using a thermal evaporation printing process. Reference will also be made here to the second layer 11 comprising a printed photovoltaic module 5, in particular a photovoltaic module 5 printed on the substrate of the second layer 11.

[0108] It should be noted that, once the photovoltaic module 5 has been applied to the substrate, a layer of self-adhesive substance can be deposited on all or part of the upper and / or lower surface of the substrate. In these cases, the second layer 11 can be a self-adhesive layer, which facilitates its assembly with the other layers, in particular with the first layer 10 and / or with the third layer 12 of the stack 9a.

[0109] In the stack 9a, the third layer 12 further comprises a substrate, preferably flexible or compliant, comprising the electric energy accumulator 6 of the self-determination device 3. This substrate of the third layer 12 can be a film on which the accumulator 6 is arranged. Such a substrate can be made of a material belonging to the family of polymers.

[0110] The accumulator 6 can be a lithium battery or a semiconductor battery. Such a battery 6 is applied to the upper surface of the substrate using processes known in the state of the art, such as:

[0111] - printing processes carried out on a flexible polymer substrate, for example this involves lithium batteries at this time; or

[0112] - three-dimensional printing processes, for example this involves semiconductor batteries such as lithium metal semiconductor batteries.

[0113] Here too reference will be made to the third layer 12, which comprises a printed electric energy accumulator 6, in particular an electric energy accumulator 6 printed on the substrate of the third layer 12.

[0114] Such a process makes it possible to obtain a third layer 12 comprising the accumulator 6, which is flexible and ultra-thin.

[0115] Furthermore, it should be noted that, once the accumulator 6 has been applied to the substrate, a layer of self-adhesive substance can be deposited on all or part of the upper and / or lower surface of the substrate. In these cases, the third layer 12 can be a self-adhesive layer, which facilitates its assembly with the other layers, in particular with the second layer 11 and / or with the fourth layer 13 of the stack 9a.

[0116] It should be noted that the accumulator 6 is used to store the electric energy produced by the photovoltaic module 5 and to release it when necessary to power the determination device 3, in particular the first and second light sources 4a, 4b and the at least one detection element 23.

[0117] In the stack 9a, the fourth layer (and last layer) 13 forms the hidden face of the dial 2a. This fourth layer 13 is formed of a preferably flexible or compliant substrate, which includes the control unit 7. Such a substrate for the fourth layer 13 can be for example a flexible PCB (Printed Circuit Board) on which the control unit 7 is arranged, in particular on the upper face of the PCB, so on the upper face of the substrate. In this context, the control unit 7 can be structured on said upper face of the substrate using a three-dimensional printing process or a polymer printing process.

[0118] In a second alternative embodiment, the stack 9b forming the dial 2b comprises three thin layers 10, 11, 14 which are joined together. It should be noted that the second alternative embodiment differs from the first alternative embodiment in that it comprises three layers 10, 11, 14 instead of four layers 10, 11, 12, 13 as in the first alternative embodiment. In the second alternative embodiment, the electric energy accumulator 6 of the autonomous determination device 3 is now included in the third layer (and last layer) 14 of the stack 9b with the control unit 7.

[0119] This third layer (and last layer) 14 of the stack 9b forming the hidden face of the dial 2b consists of a preferably flexible or compliant substrate on which the battery 6 and the electronic circuit 8 constituting the control unit 7 are structured, preferably on the upper face of the substrate. The accumulator 6 and the control unit 7 can be structured on the upper face of the substrate using a three-dimensional printing process or a polymer printing process. It should be noted that such a substrate can be for example a flexible PCB.

[0120] In summary, in the second alternative embodiment, the stack 9b comprises:

[0121] - the first layer 10 forming the visible face 20a of the dial 2b, said first layer including the first and second light sources 4a, 4b and the detection element 23;

[0122] - the second layer 11 including the photovoltaic module 5; and

[0123] - the third layer 14 forming the hidden face 20b of the dial 2b, said third layer including the accumulator 6 and the control unit 7.

[0124] It should be noted that in the second alternative embodiment, the first and second layers 10, 11 are similar to those of the first alternative embodiment of the stack 9a.

[0125] Furthermore, with reference to Figure 3 and Figure 5The electronic circuit 8 of the control unit 7 comprises a first connection element 15a connected to the first and second light sources 4a, 4b and to the connection element 16 of the at least one detection element 23 for determining the position of the pointer and displaying visual information according to said position. The electronic circuit 8 further comprises a second connection element 15b connected to the first connection element 17a of the battery 6.

[0126] In a third alternative embodiment, not shown, the stack forming the dial comprises two interconnected layers. It should be noted that the third alternative embodiment differs from the second alternative embodiment in that it comprises two layers instead of three layers 10, 11, 14 as in the second alternative embodiment. In the third alternative embodiment, the photovoltaic module 5 of the self-determination device 3 is now comprised in the first layer and in particular on the lower surface of the substrate forming said first layer. The photovoltaic module 5 can be applied to the lower surface of the substrate of the first layer using an inkjet or screen printing process or using a thermal evaporation printing process. It should thus be noted that the first layer is thus similar to the first layer 11 of the first and second alternative embodiments, except that in the third alternative embodiment, the first layer further comprises a photovoltaic module.

[0127] In the third alternative embodiment, and similarly to the second alternative embodiment, the electrical energy battery 6 of the self-determination device 3 is comprised in the second layer (and is the last layer) of said assembly with the control unit 7. This second layer forming the hidden face of the dial consists of a substrate that is preferably flexible or compliant, on which the battery 6 and the electronic circuit 8 constituting the control unit 7 are structured, preferably on the upper surface of said substrate. The battery 6 and the control unit 7 can be structured on the upper surface of the substrate using a three-dimensional printing process or a polymer printing process. It should be noted that such a substrate can be for example a flexible PCB.

[0128] In summary, in the third alternative embodiment, the stack comprises:

[0129] - a first layer forming the visible face 20a of the dial, said first layer comprising the first and second light sources 4a, 4b, the at least one detection element 23 and the photovoltaic module 5 of the determination device 3; and

[0130] - a second layer forming the hidden face 20b of the dial, said second layer comprising the battery 6 and the control unit 7.

[0131] Furthermore, it should be noted that the event sensor of the determination device 3 described above is preferably arranged in the first layer 10 and / or in the last layer 13, 14 of the stack 9a, 9b of layers and is connected to the control unit 7 of said device 3.

[0132] Thus, in the dial 2a, 2b, the determining device 3 comprises a detection element 23, preferably dedicated to each hand, which measures the light intensity. At the determined position of the hand 24a, 24b, the light beam 29a emitted by the first light source 4a is reflected by the hand 24a, 24b into a light beam 29b towards the light detection element 23. More particularly, the emitted light beam 29a is reflected by a reflecting area 26 of the hand, defined on the lower surface of the hand. The area 26 comprises an inclined reflecting surface 27 or a diffraction grating 28 formed in the lower surface. The inclined reflecting surface 27 and diffraction grating 28 are configured to reflect such light beam 29a towards the detection element 23. In this configuration, the light intensity is measured by the element 23 and transmitted to the control unit which processes and archives the light intensity. Once the measurement of the intensity suddenly increases due to the passage of the hand above the detection element 23, the control unit determines the position of the hand. During the passage, the detection element measures the light intensity resulting from the light beam 29b reflected by the reflecting area of the hand received by the element 23. Since the minute hand is usually above the hour hand, this difference in height generates a difference in light intensity perceived by the detection element 23. Advantageously, a single first light source 4a and a single light detection element 23 can be used to identify each hand.

[0133] Determining the position of the hands can thus allow the dial 2a, 2b to implement various functions of the watch. For example, one function of the watch can correspond to detecting a loss of accuracy of the time setting. This is because, in the case of a mechanical movement, the number of driving steps is lost due to the impact of the watch, the presence of electromagnetic fields or other external disturbances. Thus, although the internal clock of the watch provides an accurate indication of the current time, the hour and minute hands provide a distorted indication of the current time, since the gears have skipped a few steps due to the influence of the external disturbances on the watch. It is therefore necessary to resynchronize the positions of the hour and minute hands. Thus, as part of the function, the control unit 7 can generate visual information from the position, sending a signal of "loss of accuracy" by controlling / driving one or more second light sources 4b.

[0134] Other functions of the watch using the determination of the position of at least one of its hands can provide the detection of the number of passes of the hands 24a, 24b over the detection element 23, for example of the second hand 24b, each pass lighting up the second light source 4b, for example the light source facing the scale, with the aim of providing a basic time setting of a certain time elapse. The start / stop / reset can be implemented by covering the watch glass. Said luminance variation is interpreted by the control unit 7 (via the light detection element 23 or by the sudden lack of energy production in the photovoltaic module 5) as a start / stop / reset signal. In said example, the number of passes of the hour hand 24a can be counted. After a given number of passes, the second light source 4b is switched on to signal that the watch should be serviced. After an additional number of passes, a second color or a blinking can indicate that a service is required.

[0135] Another function associated with the determination of the position of at least one hand of the watch can involve the display of the time system by indicating "ante meridiem (abbreviated AM)" and "post meridiem (abbreviated PM)". For example, each time the hour hand 24b passes over the detection element 23, the second light source 4b is switched on and off to indicate the period of the day (morning or afternoon).

[0136] Another function associated with the determination of the position of at least one hand of the watch can be used to illuminate the position of the hands 24a, 24b or to back light the hands (instead of using luminescent material). In the event of a low luminosity detected by the control unit 7 (via the light detection element 23 or by the lack of energy production in the photovoltaic module 5), a plurality of second light sources 4b are switched on to indicate the position of the hands. For example, in said configuration, twelve detection elements (each placed opposite a scale) can detect the position of the two hands with an accuracy of 5 minutes. Any lack of detection of the minute hand indicates that the two hands overlap.

[0137] Another function associated with the determination of the position of at least one hand of the watch can be used to count the number of passes of at least one hand 24a, 24b, thus making it possible to determine, for example, the actual operating time of the watch 1, for example between two service or maintenance operations of the watch.

[0138] It goes without saying that the present application is not limited to the above-described embodiments and that various simple alternatives and modifications can be considered by those skilled in the art without departing from the scope of the present application as defined by the appended claims.

Claims

1. A watch dial (2a, 2b) of a watch (1), characterized in that, The dial comprises means (3) for determining the position of at least one hand (24a, 24b) of the watch (1), such a dial (2a, 2b) comprising a visible face (20a) and a hidden face (20b), the dial (2a, 2b) being formed by a stack (9a, 9b) of thin layers (10, 11, 12, 13, 14) of material extending between the two faces (20a, 20b), each of the layers (10, 11, 12, 13, 14) containing one or more functional elements comprised in the means (3) as follows: - at least one light detection element (23); - at least a first light source (4a) and at least a second light source (4b); - a self-powered unit (21) comprising a photovoltaic module (5); and - a control unit (7) for managing the operation of each light source (4a, 4b) and of the at least one light detection element (23).

2. The dial (2a, 2b) according to claim 1, comprising a through hole configured to receive a shaft (25) intended to carry at least one hand (24a, 24b) of the watch (1).

3. The dial (2a, 2b) according to any one of the preceding claims, wherein the stack (9a, 9b) of thin layers (10, 11, 12, 13, 14) of material comprises a first layer (10) equipped with the visible face (20a) of the dial (2a, 2b) and comprising the at least one light detection element (23) and the first and second light sources (4a, 4b).

4. The dial (2a, 2b) according to claim 3, wherein the stack (9a, 9b) of thin layers (10, 11, 12, 13, 14) comprises a second layer (11) comprising the photovoltaic module (5).

5. The dial (2a, 2b) according to claim 1 or 2, wherein the at least one first light source (4a) and the at least one light detection element (23) are arranged so that a light beam (29a) emitted by the at least one first light source (4a) is reflected by the at least one hand (24a, 24b) towards the at least one light detection element (23).

6. The dial (2a, 2b) according to claim 1 or 2, wherein the at least one first light source (4a) is configured to emit a light beam (29a) towards a reflection area (26) of the at least one hand (24a, 24b), the reflection area (26) being configured to reflect the light beam (29a) towards the at least one light detection element (23).

7. The dial (2a, 2b) according to claim 6, wherein the reflection area (26) comprises an inclined reflective surface (27) formed in a lower surface of the at least one hand (24a, 24b).

8. Dial (2a, 2b) according to claim 6, wherein the reflective area (26) comprises a diffraction grating (28) formed in the lower surface of the at least one pointer (24a, 24b), said grating (28) being configured to reflect a light beam (29a) towards the at least one light detection element (23).

9. The dial (2a, 2b) according to claim 1 or 2, wherein The at least one first light source (4a) is a vertical cavity surface emitting laser source.

10. The dial (2a, 2b) according to claim 1 or 2, wherein The at least one second light source (4b) is able to generate visual information as a function of the determined position of the at least one pointer.

11. The watch dial (2a, 2b) according to claim 3, wherein The first layer (10) is configured so that light radiation, in particular solar radiation, and light radiation emitted by the first and second light sources (4a, 4b) can pass completely or partially through the first layer.

12. The watch dial (2a, 2b) according to claim 4, wherein The second layer (11) comprises a substrate on which the photovoltaic module (5) is printed.

13. The watch dial (2a, 2b) according to claim 4, wherein The photovoltaic module (5) is arranged on an active area of the second layer (11), said area being configured to receive light rays originating from the first layer (10) of the stack (9a, 9b) of thin layers (10, 11, 12, 13, 14).

14. The dial (2a) according to claim 4, characterized in that The stack (9a) of thin layers (10, 11, 12, 13) comprises a third layer (12) comprising an electrical energy accumulator (6) constituting an independent energy supply unit (21).

15. The dial (2a) according to claim 14, characterized in that The third layer (12) comprises a substrate on which the electrical energy accumulator (6) is printed.

16. The dial (2a) according to claim 14, characterized in that The stack (9a) of thin layers (10, 11, 12, 13) comprises a fourth layer (13) forming a hidden face (20b) of the dial (2a), said fourth layer comprising a control unit (7).

17. The dial (2b) according to claim 4, characterized in that The stack (9b) of thin layers (10, 11, 14) comprises a third layer (14) comprising a hidden face (20b) of the dial (2b), said third layer comprising a control unit (7) and an electrical energy accumulator (6) constituting an independent energy supply unit (21).

18. The watch dial (2a, 2b) according to claim 4, characterized in that The first layer (10) is rigid compared to the other layers (11, 12, 13, 14) of the stack (9a, 9b), said other layers being flexible.

19. A watch (1) characterized in that, The watch comprises a dial (2a, 2b) according to any one of the preceding claims.

20. The watch (1) according to claim 19, characterized in that, It comprises a mechanical or electromechanical timepiece movement.

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