HK40004691B - Casing element of metallic appearance with integrated communication system - Google Patents

Description

Metal-look exterior components including integrated communication systems

Technical Field

The invention relates to an exterior element of a timepiece made of a first material and having a housing comprising a communication system.

Background Art

With the advent of watches that include short-range wireless communication capabilities, such as RFID, it became necessary to find space for the communication systems. One solution has been to integrate these communication systems with elements of the watch, such as the case, the crystal, the crystal seal, or even the bezel.

However, this type of structure is impractical if these components are made of solid metal. In fact, electromagnetic interference can severely impair or even prevent communications. Integrating a communication system with non-metallic components can avoid interference, but it doesn't achieve the same visual appearance as if the components were made of solid metal. The term "visual appearance" is used here to refer to metallic sheen and color.

Document EP 1 274 150 A1 is well known, describing a watch external element that is essentially annular, fits onto the bezel of the watch, and has an opening in which an antenna for a communication system is located. This external element is not only made of a metal material, but the protrusion formed by it also has a significant impact on the design of the watch.

Summary of the Invention

The object of the present invention is to solve the disadvantages of the prior art.

To this end, the present invention relates to an external element (or "case element") of a timepiece or jewelry, comprising a body made of an insulating ceramic material, arranged to include a housing, wherein the body also includes a wireless communication system arranged in the housing, and at least a portion of the surface of the external element has a layer of metallic visual appearance, obtained by carburizing, nitriding or a combination of these two processes.

The advantage of this external element is that it is made of an insulating material so that it does not interfere with the wireless communication system, while comprising a surface layer that has a metallic visual appearance so that the external element is consistent with the object/bracelet on which it is mounted. Therefore, the appearance of the watch or jewelry is not changed compared to a traditional piece that does not include a communication system. It should be noted that the carburizing/nitriding process changes the resistance of the surface of the external element by making it conductive on its surface (ohmic resistance between 20 and 80 ohms), while the thickness is thin enough to ensure that the impact on the communication system is negligible, especially for frequencies below 1 GHz. Naturally, in addition to the surface layer, the external element itself also remains insulating.

The invention also relates to a timepiece comprising a case comprising a case middle closed by a back and a crystal, and equipped with a bezel, wherein the bezel is an external element as described above.

In this case, the invention makes it possible to obtain a rotating or non-rotating bezel system that is easy to install, allows wireless communication functions of the RFID type, and does not affect the aesthetics of a traditional metal watch.

Further characteristics of the invention are indicated in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, advantages and features of the bezel system according to the invention will be more clearly understood from the following detailed description of at least one embodiment of the invention, given by way of non-exhaustive example only, and illustrated by the accompanying drawings, in which:

- Figure 1 shows an overview of the present invention;

- Figures 2 and 3 show two detailed views of a bezel used as an external element according to the invention;

- FIG4 shows a first embodiment of the present invention;

- Figure 5 shows a second embodiment of the present invention;

- Figures 6A and 6B show two other illustrative embodiments of a bezel according to the invention.

DETAILED DESCRIPTION

1 and 2 show an external element 10 according to the invention, for example a bezel 100, mounted on a timepiece 1 comprising a case 2 closed by a back 3 and a crystal 4. This bezel 100 is an annular part comprising an upper surface and a lower surface directly visible to the wearer.

Bezel 100 can be mounted in a rotating or non-rotating position relative to the case middle. A spring-detent mechanism or locking system (not shown here) is housed within the housing of rotating bezel 100. This spring-detent mechanism comprises a spring device and a toothed element. One of the elements of the spring-detent mechanism is angularly integrated with the case middle, while the other is angularly integrated with bezel 100, allowing for angular indication/indexing of the bezel relative to the case middle.

To mount bezel 100, the timepiece includes a case middle 20 having a shoulder 21 defined by a side wall 22 and a base 23. This shoulder serves as a receptacle for the bezel. Typically, side wall 22 includes a projection 24 extending along its entire periphery. This projection 24 cooperates with base 23 and wall 22 to define a retaining groove 25. This retaining groove 25 allows the bezel to be inserted and retained therein during the process of assembly by force.

Advantageously, according to the invention, bezel 100 is equipped with a wireless communication system 102 , as shown in FIG. 3 .

In a preferred embodiment, bezel 100 is manufactured to include a main body consisting of a lower portion 100b (main body) and an upper portion 100a (decorative insert or minute display). Upper and lower portions 100a, 100b are arranged to be assembled to form the bezel. The lower and upper portions are cleverly manufactured to provide a slot 104, which serves as a receiving portion. This slot can be located in either the upper or lower portion, or can be formed by two complementary surfaces: one in the upper portion and one in the lower portion. The slot is circumferential, meaning it extends around the perimeter of the bezel, though it does not necessarily have a constant dimension. Slot 104 thus serves as a receptacle for a wireless communication system. Wireless communication system 102 may include a supporting structure, namely a printed circuit board with a shape similar to that of slot 104 (i.e., a ring shape) provided on the bezel. In this case, the printed circuit board serves as the substrate for the loop antenna, and the various electronic components that enable the communication system's functionality are arranged on the printed circuit board. The communication system may utilize the NFC (Near Field Communication) communication protocol.

The entire assembly is then placed in the groove 104 of the bezel 100 , which serves as a housing.

In order to enclose the entire assembly, a rubber-type polymer material, for example, can be directly overmolded in the groove 104 to form an overmolding 106 as shown in FIG3 . This conventional overmolding process is intended to cover the wireless communication system 102, which is formed as a whole in an annular shape. On the one hand, since the polymer material is introduced into the entire groove 104, this overall covering method makes it possible to ensure good waterproofing of the system, thereby preventing liquid from being introduced into the groove 104. The groove can also be filled by other means, such as conventional injection molding, screen printing, or resin dispensing. Once the groove is filled, the wireless communication system is mechanically maintained and can withstand shock loads and thermal changes without any problems.

On the other hand, a second advantage of this embodiment is that it makes fraudulent access to the frequently encrypted data stored in the communication circuit less easy. In fact, the communication system 102 used for this bezel 100 can utilize a contactless communication protocol of the NFC or RFID type or some other radio communication means. Thus, the bezel can be used as an electronic "tag" or label for product identification (or tracking). It can also be used for payment functions, which means that the embedded data is sensitive. Therefore, the act of overmolding the polymer on the communication system 102 makes it more difficult to obtain information, because the polymer must be dissolved before accessing the electronic circuit.

In another illustrative embodiment, visible in Figures 6A and 6B, bezel 100 is in the form of a single body provided with a groove 104 that serves as a housing for wireless communication system 102. This groove 104 can be located on one of the faces forming the body of bezel 100, regardless of whether it is visible or faces case middle 20. In the case where groove 104 is located on the face facing case middle 20, it is filled with an overmold 106, such as a polymer, plastic, or rubber, to completely cover wireless communication system 102 and ensure good water resistance. In the case where groove 104 is located on a visible surface of the bezel, it houses communication system 102, which is then overmolded with rubber or some other polymer. Groove 104 can also be closed by a cover 107, made of the same material as bezel 100, or some other material that contrasts decoratively with the bezel's material. This cover can be sealed, crimped, or even soldered to the bezel.

According to the invention, bezel 100 is manufactured in such a way as to prevent interference with wireless communication system 102. In fact, installing a communication system in a metal bezel, for example made of steel, can cause malfunction of said communication system since the metal material of the bezel shields electromagnetic fields (EM).

Therefore, the present invention proposes manufacturing the bezel from an electrically insulating material while giving it a metallic appearance on all or at least a portion of its visible surface. In this case, the material of choice is ceramic. This material is chosen because its insulating properties prevent any interference with wireless communications. However, this material is also chosen for its mechanical scratch resistance, not only due to its inertness, but also, as is conceivable, due to its plastic material.

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

Ingeniously, the bezel receives a treatment that gives it a similar appearance to the case. While a case made of metal material would have a metallic appearance, the ceramic used for the external element (in this case, the bezel) would have a completely different appearance, which would otherwise detract from the overall aesthetics of the product. This treatment thus imparts a metallic appearance to the surface of the ceramic bezel. This metallic appearance is accompanied by metallic properties, specifically a non-zero but sufficiently low electrical conductivity and a thickness sufficiently thin to accommodate the passage of electromagnetic waves received and/or transmitted by the wireless communication system in the bezel.

In a first embodiment, visible in FIG4 , the treatment of the external element 10 is a carburizing or nitriding treatment. Similar carburizing/nitriding stages involve changing the chemical composition of the component (by replacing the oxygen of the starting ceramic material with carbon or nitrogen, respectively). Thus, a similar method consists of placing the component to be carburized/nitrided, such as a bezel 100 consisting of one or two parts 100 a and 100 b , in a capsule whose atmosphere contains carbon atoms or nitrogen atoms, respectively, and activating the surface of the workpiece to be carburized/nitrided by uniform heating over its entire surface or in selected areas 10 ′. The surface of the external element 10 is then heated to a temperature between 700 and 1100° C. for a period of 30 to 180 minutes. Under the influence of this temperature, the carbon or nitrogen atoms in the capsule atmosphere bond with the ceramic in the areas 10 ′ of the external element 10. Advantageously, this involves converting the surface of the region 10' of the external element 10 into a thickness of carbide or nitride having a metallic appearance close to the color of platinum or gold, respectively, without the risk of degradation by delamination as is the case with metal deposition.

More specifically, the surface layer 10' having a zirconium carbide or zirconium nitride structure extends from the surface to an average depth of between 10 and 200 nm. This thickness has the advantage of providing a metallic appearance to the external element 10 while being thin enough to avoid interfering with wireless communication systems.

In a second embodiment visible in FIG. 5 , the treatment for giving the external element 10 a metallic appearance consists in depositing a layer 10 ″. This deposited layer is a metal layer, an oxide layer, a nitride layer, a carbide layer, a boride layer or a combination thereof on the ceramic surface of the external element 10 , produced by wet layering or layering under a controlled atmosphere, preferably by PVD. This layer will have a thickness of about 10 nm to 2-3 μm.

In these two embodiment variations, it will be appreciated that the treatment of the external element may be applied to the entire surface of the external element, or only to a portion thereof. In the case of a partial treatment, the treatment is applied to the surface of the external element visible to the wearer. In fact, in the case of a bezel, a portion of the surface faces the shoulder of the watch case, while another portion of the surface is visible to the wearer. Furthermore, the choice of treatment for the external element may have an aesthetic purpose, for example, to display a marking, a number, a logo, or some other decorative element.

It will be appreciated that various modifications and/or improvements and/or combinations obvious to a person skilled in the art may be made to the different embodiments of the invention described above without departing from the scope of the invention as defined by the accompanying claims.

Therefore, in order to improve water resistance, it may be advisable to provide a joint between the lower and upper parts of the bezel.

It will also be understood that the external element may be a link of a bracelet containing a wireless communication system, the back of a watch case, or any other ceramic external component.

Claims (6)

1. An external element (10) for a watch or jewelry, the external element comprising a body made of an insulating ceramic material, the body being arranged to include a receiving portion (104), characterized in that the external element further comprises a wireless communication system (102) disposed in the receiving portion (104), and at least a portion (10') of the surface of the external element has a metallic visual appearance layer, the layer being obtained by carburizing, nitriding or a combination of both processes. 2. The external element (10) as claimed in claim 1, characterized in that the body of the external element comprises a lower portion (100b) and an upper portion (100a), the lower portion and the upper portion being joined together to form the external element, the lower portion and the upper portion being arranged to expose a receiving portion (104) between them. 3. The external element (10) as claimed in claim 1, characterized in that the metallic visual appearance layer has a thickness of 10 to 2000 nm. 4. The external element (10) as claimed in claim 1, characterized in that the metallic visual appearance layer has a thickness of 10 to 200 nm. 5. A watch (1) comprising a case (2) and a bezel (100), the case (2) comprising a case intermediate part (20) closed by a back (3) and a crystal (4), characterized in that the bezel (100) is an external element (10) according to any one of the preceding claims. 6. The watch as claimed in claim 5, wherein the intermediate part of the case includes a shoulder (21) defined by a sidewall (22) and a base (23), and the bezel is disposed in the shoulder.