EP3069200B1 - Electromechanical or digital watch comprising a dial and method for manufacturing such a dial - Google Patents

Description

The present invention relates to a watch comprising a dial. More specifically, the present invention relates to an electromechanical or digital watch comprising at least one electronic device arranged in the watch case.

For the purposes of the present invention, the term "electromechanical watch" means a watch comprising at least one indicator of a time value or of a magnitude unrelated to time driven by an electric motor. Moreover, digital watch means a watch comprising at least one digital display device of a time magnitude or of a magnitude unrelated to time.

Similarly, in the sense of the invention, the term "dial" means an indicator organ which carries various indications, hourly or not related to time.

Electromechanical watches, as well as digital watches, comprise a plurality of discrete or integrated electronic components necessary for their operation. These electronic components are typically mounted on printed circuit boards housed in the watch cases, below the surface of the dial and at a distance therefrom.

It is understood that these printed circuit boards are additional components sources of additional manufacturing costs and which take up space in the volume of the watch case, so that it is sometimes difficult to accommodate them.

The present invention aims to remedy these disadvantages as well as others by providing a dial for a watch electromechanical or digital enabling advantageously to overcome, at least partially, printed circuit boards.

For this purpose, the present invention relates to an electromechanical or digital watch, the watch comprising a caseband which delimits with an ice a watch case, the ice comprising an upper face oriented on the side of a user, and a lower face oriented on the side. of the watch case, the watch also comprising a dial made of a non-electrically conductive material, the dial comprising a lower surface and an upper surface situated on the side of an observer, the watch being characterized in that tracks electrically conductive connectors for connecting one or more electronic components are structured on at least one of the lower or upper surfaces of the dial.

According to a complementary characteristic of the invention, the dial is made of glass, a plastic material or even a ceramic material.

With these features, the present invention provides a watch whose dial is made of a non-electrically conductive material, so that at least one of the lower and upper surfaces of this dial can be used for structuring electrically conductive tracks for the electrical connection of at least one discrete or integrated electronic component. It is thus possible to overcome or, at least, to limit the surface of the printed circuit boards necessary for mounting the electronic components of the watch, which makes it possible to limit the costs in terms of the number of printed circuit boards used. and manufacturing time, as well as reduce the clutter of the watch movement housed in the watch case.

• la figure 1 est une vue en coupe d'une montre équipée d'un cadran selon l'invention, et
• la figure 2 est une vue en coupe d'une montre équipée d'un cadran selon une variante de réalisation de l'invention.

Other features and advantages of the present invention will emerge more clearly from the detailed description which follows of an exemplary embodiment of a watch according to the invention, this example being given in purely illustrative and not limiting only in connection with the accompanying drawing in which:

• the figure 1 is a sectional view of a watch equipped with a dial according to the invention, and
• the figure 2 is a sectional view of a watch equipped with a dial according to an alternative embodiment of the invention.

The present invention proceeds from the general inventive idea of using one and / or the other of the upper and lower surfaces of a watch dial made of a non-conductive material of electricity to structure conductive tracks allowing to connect discrete or integrated electronic components necessary for the operation of the watch. In this way, it is possible to eliminate, or at least limit the surface of the printed circuit boards, which limits the time and manufacturing costs, and reduce the size of the watch movement housed in the circuit. watch box.

The present invention will be described in connection with a timepiece comprising an ice on the lower surface of which are structured tactile keys. It goes without saying that this example is given for purely illustrative and not limiting purposes only, and that a watch face according to the invention can be used with any type of electronic device integrated in a watch case.

The figure 1 attached to the present patent application is a sectional view of a watch equipped with a dial according to the invention. Designated as a whole by the general numerical reference 1, this watch comprises a middle part 2 which delimits with a mirror 4 a watch box 6.

The window 4 comprises an upper face 8 directed towards the side of a user of the watch 1, and a lower face 10 directed towards the side of the watch case 6. On the lower face 10 of the window 4 is arranged an electronic device. The electronic device can be of any type. he may be a digital display device, for example liquid crystal, or (see single figure) first conductive tracks 12 made of a transparent electrically conductive material such as tin oxide indium, better known under the name Anglo-Saxon Indium-Tin Oxide or ITO. These first conductive tracks 12 have the function of materializing on the surface of the glass 4 tactile keys sensitive to variations in capacity and allowing the user, by applying a finger 14, to introduce instructions into an electronic circuit 16 touch key management. This electronic management circuit 16 is mounted on a lower surface of a dial 18 according to the invention housed in the watch case 6, under and away from the first conductive tracks 12, and supported by a flange 20. The assembly is completed by an electronic circuit 22 which controls the execution of a watchmaking or other function according to the instructions provided by the electronic management circuit 16.

The first conductive tracks 12 define electrical contact pads 24 that it is necessary to transfer from the lower face 10 of the glass 4 to the dial 18. According to the present invention, the dial 18 comprises for this purpose second conductive tracks 26 which correspond to the electrical contact pads 24 and which are connected to the electronic management circuit 16 and the electronic control circuit 22. In the example shown in the drawing, the second conductive tracks 26 are structured only on a lower face 28 of the dial 18. It goes without saying, however, that conductive tracks may also be structured on the upper face of the dial 18, in particular if these conductive tracks are transparent.

As illustrated in the drawing, it may be provided for this purpose for example a flange 20 of generally circular shape disposed under the window 4 of the watch 1. This flange 20 is made of a non-electrically conductive material and comprises means which shall make it possible to provide the electrical connection between the electrical contact pads 24 and the second conductive tracks 26. These electrical connection means are constituted by third conductive tracks 32 which come into contact with the electrical contact pads 24 on the one hand, and with the second conductive tracks 26 on the other hand. To ensure good electrical contact between the third conductive tracks 32 formed on the flange 20 and the second conductive tracks 26 formed under the surface of the dial 18, through holes or vias 34 are formed in the flange 20, in the region where it It supports the dial 18. According to one variant, it is also possible to structure contact pads (also known as the bumps) on the third conductive tracks 32 at the places where these third conductive tracks 32 are opposite second conductive tracks 26.

In the case where the dial 18 is made of an electrically nonconductive material such as glass, a plastic material or even a ceramic material, the second conductive tracks 26 may be made for example by photolithographic structuring of a layer ITO. The second conductive tracks 26 may also be made for example of copper, silver or aluminum by means of a method such as a laser treatment method making it possible to obtain a device known as the English molded interconnect device or MID. Subsequently, the second conductive tracks 26 are structured by an electroplating process. According to a variant, it is also possible to structure the second conductive tracks 26 on the surface of the dial 18 by printing an electrically conductive ink. It is also conceivable to make the dial 18 by a method of bi-injection of a plastic material and a conductive material followed by an electroplating step.

It goes without saying that the present invention is not limited to the embodiment which has just been described and that various modifications and simple variants can be envisaged by those skilled in the art without departing from the scope of the invention as defined by the appended claims. It will be understood in particular that in products such as the wristwatch marketed under the registered trademark T-Touch®, the electrical connection between the tactile keys structured on the underside of the glass and the electronic circuit for managing these tactile keys can also be achieved by means of elastomeric connectors, also known by the name commercial Zébra® connectors. These elastomeric connectors consist of an alternating succession of conductive layers and insulating layers typically made of elastomer which provide high density connections of electrical paths. It is also obvious that the conductive tracks structured on the dial according to the invention do not necessarily serve to connect tactile keys formed on the underside of a watch crystal to electronic management and control circuits fixed on the dial. . It is thus quite possible to structure on one and / or the other of the lower and upper surfaces of the dial conductive tracks for interconnecting for example electronic circuits for managing and controlling a component housed in the volume of the watch case as an electric motor step-by-step.

The figure 2 is a sectional view of a watch equipped with a dial according to an alternative embodiment of the invention. In what follows, the elements identical to those described above in connection with the figure 1 will be designated by the same numerical references. As can be seen from the examination of the figure 2 a flange 34 is made of a piece with a dial 36. This flange 34 / dial 36 is made of a non-electrically conductive material and comprises means which must make it possible to ensure the electrical connection between the flats. electrical contact 24 formed on the lower face 10 of the glass 4 and the management electronic circuitry 16 and control 22 mounted on a lower surface 38 of the assembly 34 / dial 36. For this purpose, conductive tracks 40 are provided on at least one of the lower faces 38 or 42 of the upper assembly 34 / dial 36 and electrically connect the electrical contact pads 24 to the electronic management circuit 16 and the electronic control circuit 22. In the example shown in the drawing, the conductive tracks 40 are structured only on the lower face 38 of the flange assembly 34 / dial 36. However, it goes without saying that conductive tracks may also be structured on the upper face 42 of the flange assembly 34 / dial 36, especially if these conductive tracks are transparent. In the case where the assembly highlights 34 / dial 36 is made of a non-conductive material of electricity such as glass, a plastic material or even a ceramic material, the conductive tracks 40 can be made for example by photolithographic structuring an ITO layer. The conductive tracks 40 may also be made for example of copper, silver or aluminum by means of a method such as a laser treatment method making it possible to obtain a device known as Molded Interconnect Device or MID. . Subsequently, the conductive tracks 40 are structured by an electroplating process. According to a variant, it is also possible to structure the conductive tracks 40 on the surface of the flange assembly 34 / dial 36 by printing an electrically conductive ink. It is also conceivable to make the whole flange 34 / dial 36 by a method of bi-injection of a plastic material and a conductive material followed by an electroplating step. It will be understood that the embodiment which has just been described in connection with the figure 2 has the particular advantage that, in the case where it is desired to connect an electronic component arranged on the lower surface of the glass with other electronic components fixed on the dial, it avoids all the connection elements of the type bumps or vias normally used to ensure the connection between the flange and the dial.

Claims (4)

1. Electromechanical or digital watch, the watch (1) including a middle part (2) which, with a glass (4), delimits a watch case (6), the glass (4) including an upper surface (8) oriented towards a user, and a lower surface (10) oriented towards the watch case (6), the watch (1) also including a dial (18; 36) made of an electrically non-conductive material, the dial (18; 36) including a lower surface (28) and an upper surface (30) located on the side of a user, electrically conductive paths (26; 40) for the connection of one or more electronic components (16, 22) being structured on at least one of the lower (28) or upper (30) surfaces of the dial (18; 36), the watch including a flange (20; 34) provided with means for ensuring, via the electrically conductive paths (26), the electrical connection between an electronic device arranged on the lower surface (10) of the glass (4) and the electronic components (16, 22), the watch being characterized in that the flange (20) supports the dial (18).
2. Electromechanical or digital watch, the watch (1) including a middle part (2) which, with a glass (4), delimits a watch case (6), the glass (4) including an upper surface (8) oriented towards a user, and a lower surface (10) oriented towards the watch case (6), the watch (1) also including a dial (18; 36) made of an electrically non-conductive material, the dial (18; 36) including a lower surface (28) and an upper surface (30) located on the side of a user, electrically conductive paths (26; 40) for the connection of one or more electronic components (16, 22) being structured on at least one of the lower (28) or upper (30) surfaces of the dial (18; 36), the watch including a flange (20; 34) provided with means for ensuring, via the electrically conductive paths (26), the electrical connection between an electronic device arranged on the lower surface (10) of the glass (4) and the electronic components (16, 22), the watch being characterized in that the flange (34) is made in one-piece with the dial (36).
3. Watch according to any of claims 1 or 2, characterized in that the dial (18; 36) is made of glass, of a plastic material or of a ceramic material.
4. Watch according to any of claims 1 to 3, characterized in that the conductive paths (26; 40) are made of indium-tin oxide, copper, silver, aluminium or by means of a conductive ink.

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