CH712717B1 - Metallic-look cladding element with integrated communication system - Google Patents

Abstract

The invention relates to a casing element (10) of a timepiece comprising a body (100) made of an insulating material arranged to comprise a housing comprising a wireless communication system. At least part of the surface of the element is provided with a layer of metallic appearance.

Description

[0001] The present invention relates to a timepiece covering element made of a first material and having a housing comprising a communication system.

TECHNOLOGICAL BACKGROUND

[0002] The present invention relates to a rotating or non-rotating bezel for a timepiece.

[0003] Rotating or non-rotating bezel systems are known. A rotating bezel system comprises an annular bezel having an upper face and a lower face, the upper face being the face visible to the user. This bezel may comprise a toothing cooperating with a spring element for rotating bezel systems. This cooperation between the spring element and the toothing of the bezel then makes it possible to have a step-by-step rotating bezel.

[0004] With the advent of short-range wireless communication functions such as RFID, it has been necessary to find spaces for the communication systems. One solution has been to integrate these communication systems into the glass or into the glass seal. Also known is a bezel, ideally made of a non-conductive material such as ceramic, provided with a recess forming a housing in which the communication system consisting of at least one electronic circuit and an antenna is placed. The whole is then filled with a resin and closed with a non-conductive cover or equivalent.

[0005] However, this type of construction is difficult to achieve if the bezel and/or the cover are made of a metal that conducts radiofrequency waves. Indeed, this poses problems of disturbances that will significantly degrade or even prevent the communication function. Similarly, if the watch case is metallic, the performance of the communication system may be disrupted and therefore limited. The fact of switching to non-conductive materials ensures the function, but therefore does not allow for a metallic appearance or shine.

SUMMARY OF THE INVENTION

[0006] The invention aims to overcome the drawbacks of the prior art.

[0007] For this purpose, the invention relates to a timepiece dressing element comprising a body made of an electrically insulating material, said body being arranged to comprise a housing, characterized in that it further comprises a communication system arranged in the housing and in that at least part of the surface of said dressing element has a metallic-looking layer. Such a metallic-looking layer means that this layer has the color and luster of metal.

[0008] This covering element has the advantage of being made of an insulating material so that it does not disturb the wireless communication system while having a metallic appearance so that said covering element matches the object/bracelet on which it is mounted.

[0009] In a first advantageous embodiment, said body of the bezel comprises a lower part and an upper part assembling to form said covering element, the lower part and the upper part being arranged to reveal a housing between them.

[0010] In a second advantageous embodiment, the lower part and the upper part are made of ceramic.

[0011] In a third advantageous embodiment, the metallic appearance layer is a layer applied to the surface of said cladding element.

[0012] In a fourth advantageous embodiment, the metallic appearance layer is the surface of the carbide cladding element, the insulating material being ceramic.

[0013] In a fifth advantageous embodiment, the metallic appearance layer is the surface of the nitrided covering element, the insulating material being ceramic.

[0014] In a sixth advantageous embodiment, the metallic appearance layer has a thickness of between 10 and 200 nm.

[0015] In another advantageous embodiment, the metallic-looking layer has a thickness of between 10 and 2000 nm.

[0016] The invention further relates to a timepiece, comprising a case comprising a middle part closed by a back and a crystal, and provided with a bezel, characterized in that the bezel is the exterior element according to one of the preceding claims.

[0017] In a first advantageous embodiment, the case comprises a shoulder defined by a side wall and a base, and in which the bezel is arranged.

BRIEF DESCRIPTION OF THE FIGURES

[0018] The aims, advantages and characteristics of the bezel system according to the present invention will appear more clearly in the following detailed description of at least one embodiment of the invention given solely by way of non-limiting example and illustrated by the appended drawings in which: – Figure 1 represents a general view of the present invention; – Figures 2 and 3 represent two detailed views of the bezel acting as a trim element according to the present invention; – Figure 4 represents a first embodiment of the present invention; – Figure 5 represents a second embodiment of the present invention; – Figures 6A and 6B represent two other exemplary embodiments of the bezel according to the present invention.

DETAILED DESCRIPTION

[0019] The present invention proceeds from the general inventive idea which consists of providing a rotating or non-rotating bezel system, being simpler to mount, and allowing a wireless communication function of the RFID type.

[0020] Figures 1 and 2 show a covering element 10 such as a bezel 100 according to the invention, this bezel 100 being mounted on a timepiece 1 which comprises a case 2 closed by a back 3 and a crystal 4. This bezel 100 is an annular-shaped part which comprises an upper face directly visible to the user and a lower face.

[0021] This bezel 100 may be mounted rotating or not at the caseband. In the case of a rotating bezel 100, a spring-notch assembly or snap-in system (not shown) is arranged. This spring-notch assembly comprises spring means and a toothed element. One of the elements of the spring-notch assembly will be angularly secured to the caseband while the other will be angularly secured to the bezel 100 so as to allow the angular indexing of the bezel relative to the caseband.

[0022] For the assembly of the bezel 100, the timepiece comprises a caseband 20 in which a shoulder 21 is arranged, this shoulder 21 being defined by a side wall 22 and a base 23. This shoulder serves as a housing for the bezel. In general, the side wall 22 comprises a protrusion 24 extending over the entire perimeter of the side wall 22. This protrusion 24 makes it possible to define, in cooperation with the base 23 and the wall 22, a holding groove 25. This holding groove 25 allows, during the force assembly of the bezel, that the latter is inserted therein and held.

[0023] Advantageously according to the invention, the glasses 100 are equipped with a wireless communication system 102 as visible in FIG. 3.

[0024] In a preferred example, the bezel 100 is made so as to comprise a body composed of a lower part 100b (main body) and an upper part 100a (decorative insert or timer). This upper part 100a and this lower part 100b are therefore arranged to assemble in order to form said bezel. The lower part and the upper part are cleverly made so that a groove 104 serving as a housing is present. This groove can be arranged on the upper part or on the lower part or be formed by two complementary surfaces: one on the upper part and one on the lower part. This groove is peripheral, that is to say extending on the periphery of the bezel, but is not necessarily of constant dimensions. This groove 104 then serves as a housing in order to place the wireless communication system therein. This wireless communication system 102 may comprise a support, i.e. a printed circuit whose shape is similar to that of the groove 104 arranged on the bezel, i.e. a ring shape. In the present case, the printed circuit serves as a substrate for a loop antenna and the various electronic components allowing the operation of the communication system are arranged therein. The communication system may use the NFC (Near-Field Communication) communication protocol.

[0025] The whole is then placed in the groove 104 of the bezel 100 acting as a housing.

[0026] To close the whole, a polymer material for example of the rubber type can be overmolded directly in the groove 104 forming an overmolding 106 as visible in FIG. 3. This conventional overmolding operation is intended to completely cover the wireless communication system 102 having a ring shape. This total covering makes it possible on the one hand to ensure good sealing of the system since the polymer material is inserted into the entire groove 104 thus preventing liquids from entering. It is also possible to fill the groove by other means, such as conventional injection, screen printing or dispensing of resin. Once the groove is filled, the wireless communication system is thus mechanically maintained and can withstand without problem the constraints of shocks and thermal variations.

[0027] On the other hand, a second advantage of this embodiment is that it makes it less easy to gain fraudulent access to the often encrypted data stored in the communication circuit. Indeed, the communication systems 102 for this bezel 100 can use contactless communication protocols such as NFC or RFID or other wireless telecommunication means. This bezel can therefore be used as a 'Tag' or electronic label for product recognition (or tracking). It can also be used for payment functions, which implies that the embedded data is sensitive. Consequently, overmolding a polymer on the communication system 102 makes it more difficult to recover information because it becomes necessary to dissolve this polymer before having access to the electronic circuit.

[0028] In another exemplary embodiment visible in FIGS. 6A and 6B, the bezel 100 is in the form of a single body provided with a groove 104 acting as a housing for the wireless communication system 102. This groove 104 can be arranged on one of the faces of the body forming the bezel 100 whether it is visible or facing the caseband 20. In the case where the groove 104 is arranged on one of the faces facing the caseband 20, the groove will be filled for example by an overmolding 106 made of polymer, plastic or rubber to completely cover the wireless communication system 102 and ensure good sealing. In the case where the groove 104 is arranged on one of the visible faces of the bezel, this groove makes it possible to place the communication system 102 therein which will then be overmolded with rubber or other polymer. It is also possible that the groove 104 is closed by a cover 107 made of the same material as the bezel 100 or another material contrasting with the material of the bezel in a decorative manner. This cover can be glued or chased or even brazed onto the bezel.

[0029] According to the invention, the bezel 100 is made so as to avoid disturbing the wireless communication system 102. Indeed, the mounting of the communication system in a metal bezel, made of steel for example, leads to malfunctions of said communication system due to the screening of the electromagnetic (EM) fields by the metal material of the bezel.

[0030] The invention therefore proposes to produce the bezel in an electrically insulating material but still having a metallic appearance over all or at least part of its visible surface. The material chosen here is a ceramic material. Such a material is chosen for its insulating properties avoiding any disturbances of the wireless communication circuit. But this material is also chosen for its mechanical resistance to scratches in particular as well as for its more noble side than a plastic material, which can also be considered.

[0031] The lower part and the upper part are therefore made of ceramic material.

[0032] Cleverly, the bezel receives a treatment allowing it to have an appearance similar to that of the watch case. Indeed, the watch case made of metallic material has a metallic appearance while the ceramic used for the exterior element, here a bezel, has a completely different appearance which can harm the overall aesthetics of the product. This treatment therefore gives a metallic appearance to the surface of the ceramic bezel. Said metallic appearance is accompanied by metallic properties, in particular a non-zero but sufficiently low conductivity and on a sufficiently thin thickness to allow the electromagnetic waves received and/or emitted by the wireless communication system housed in the bezel to pass through.

[0033] In a first embodiment visible in FIG. 4, the treatment of the cladding element 10 is a carburizing or nitriding treatment. Such a carburizing/nitriding step consists in modifying the chemical composition of the part (by replacing the oxygen of the original ceramic with carbon or nitrogen, respectively). Such a method therefore consists in placing the part to be carburized/nitrided, for example the bezel 100 consisting of one part or two parts 100a and 100b, in an enclosure whose atmosphere contains carbon or nitrogen atoms respectively and in activating by heating the surface of the part to be carburized/nitrided uniformly over its entire surface or in selected areas 10'. The surface of the cladding element 10 is then heated to a temperature of between 700 and 1100°C for a period of 30 to 180 minutes. Under the effect of this temperature, the carbon or nitrogen atoms of the atmosphere of the enclosure combine with the ceramic surface in the zones 10' of the covering element 10. Advantageously, this involves a transformation of the surface of the zones 10' of the covering element 10 over a certain thickness into carbide or nitride having a metallic appearance of a color close to platinum or gold respectively, without risk of deterioration by peeling as a metal deposit could do.

[0034] More particularly, the surface layer 10' which has the structure of zirconium carbide or zirconium nitride extends from the surface over an average depth of between 10 and 200 nm. This thickness has the advantage of giving the covering element 10 a metallic appearance while being sufficiently thin to avoid disturbing the wireless communication system.

[0035] In a second embodiment visible in FIG. 5, the treatment allowing the cladding element 10 to have a metallic appearance consists of depositing a layer 10". This deposited layer is a metallic, oxide, nitride, carbide, boride layer or a combination on the ceramic surface of the cladding element 10 by a wet or controlled atmosphere layer deposition method, preferably PVD. This layer will have a thickness of approximately 10 nm to 2-3 µm.

[0036] In a variant of these two embodiments, it will be understood that the treatment of the covering element can be carried out on the entire surface of the covering element or be only partial. In the case where the treatment is partial, the treatment will be carried out on the surface of the covering element which will be visible to the user. Indeed, for a bezel, part of the surface is opposite the shoulder of the watch case while the other part of the surface is visible to the user. Also, the selectivity of the treatment of the covering element can have an aesthetic purpose, for example to reveal indexes, numbers, a logo or any other decorative element.

[0037] It will be understood that various modifications and/or improvements and/or combinations obvious to those skilled in the art can be made to the different embodiments of the invention set out above without departing from the scope of the invention defined by the appended claims.

[0038] Thus, the presence of a seal between the lower part and the upper part of the bezel may be provided in order to improve the sealing.

[0039] It will also be understood that the decorative element may be a bracelet link, the bottom of a watch case or any other ceramic decorative part containing a wireless communication system.

Claims (10)

1. A covering element (10) of a timepiece comprising a body made of an insulating material, said body being arranged to comprise a housing (104), characterized in that it further comprises a wireless communication system (102) arranged in the housing (104) and in that at least a portion (10') of the surface of said covering element has a metallic-looking layer. 2. Covering element (10) according to claim 1, characterized in that the body of said covering element comprises a lower part (100b) and an upper part (100a) assembling to form said covering element, the lower part and the upper part being arranged to reveal a housing 104 between them. 3. Covering element (10) according to claim 2, characterized in that the lower part (100b) and/or the upper part (100a) are made of ceramic. 4. Covering element (10) according to one of the preceding claims, characterized in that the metallic appearance layer is a layer (10") applied to the surface of said covering element. 5. Covering element (10) according to one of claims 1 to 3, characterized in that the metallic-looking layer is the surface (10') of the carbide-coated covering element, the insulating material being ceramic. 6. Covering element (10) according to one of claims 1 to 3, characterized in that the metallic appearance layer is the surface (10') of the nitrided covering element, the insulating material being ceramic. 7. Covering element (10) according to one of claims 5 or 6, characterized in that the metallic appearance layer has an average thickness of between 10 and 200 nm. 8. Covering element (10) according to claim 4, characterized in that the metallic appearance layer has a thickness of between 10 and 2000 nm. 9. Timepiece (1) comprising a case (2) comprising a caseband (20) closed by a back (3) and a crystal (4) and provided with a bezel (100), characterized in that the bezel (100) is the exterior element (10) according to one of the preceding claims. 10. Timepiece according to claim 9, characterized in that the case middle comprises a shoulder (21) defined by a side wall (22) and a base (23) and in which the bezel is arranged.