EP0766152B1 - Timepiece provided with an antenna - Google Patents

Description

The present invention relates to a timepiece intended to be worn on the arm or wrist, said part comprising either a dipole antenna or an antenna with radiant slit capable of picking up and / or emitting a field electromagnetic carrying radio messages, a case comprising members for displaying the time and a micro transceiver that receives or transmits messages using the antenna.

We already know equipped timepieces a dipole antenna and a micro-receiver to receive broadcast signals. US Patent 5,317,326 in the name from Motorola, Inc., for example, describes a part timepiece in the form of a wristwatch which has a folded dipole antenna housed in the bracelet.

Place the antenna in the strap of a fitting watch connection problems between the transceiver which is located in the watch case and the antenna which is an integral part of the bracelet. The passage of elements conductors connecting the antenna to the receiver through the housing therefore poses construction problems which lead to solutions that are never simple. Of plus, at the point of this passage, the conductive elements are almost continuously mechanically stressed when the watch is worn and break relatively quickly, if resources are not used to avoid this break. These means are also expensive and complicate the operation of changing the bracelet, this last to be specially made since the bracelet has an antenna and therefore cannot be replaced by a bracelet currently existing on the market.

Attempts have, however, been made to resolve this problem. Thus, the English abstract of document JP-A-52-48364 published in "Patent Abstracts of Japan", vol.1, No 116, October 4, 1977, page 4486 E 77, describes a play timepiece which includes a micro-receiver and an antenna in the case of a watch intended to be worn by a person. This timepiece has two windows attached to each other. The antenna, of a type single-line, is interposed between these two windows.

However, place the antenna in the housing of a watch requires miniaturization of the antenna because very limited space available for mounting the antenna. If it is possible to decrease in some measure the dimensions of the antenna for a given frequency, it will always be at the expense of its other characteristics, such as gain or band busy. At a fixed frequency, a miniature antenna will have therefore a gain and a lower bandwidth than a normal size antenna placed in the bracelet.

Thus, the object of the present invention is to provide a timepiece of the type defined above which overcomes the disadvantages of the prior art.

The object of the invention is also to provide a such a timepiece including the antenna as such as well as its electrical dimensions are optimized.

Furthermore, the object of the invention is to provide a such a timepiece in which the construction of the antenna and its mounting in the housing are simple. This construction is also compact.

To this end, the invention relates to a part timepiece intended to be worn on the wrist, the piece comprising either a dipole antenna or a radiant slot capable of picking up and / or emitting a field electromagnetic carrying radio messages, a first housing comprising members for displaying the time and a micro transceiver that receives or transmits messages using the antenna. The timepiece is characterized in that it further comprises a second box intended to receive the first box of so that the outer surface of the first housing and the inner surface of the second housing define a mounting groove, in that the antenna includes a dielectric substrate and at least one conductive element in printed circuit attached to the substrate and which defines a radiating element of said antenna and in that the antenna is located in the mounting groove so that it either wrapped around the first box.

Thanks to this combination of features, on the one hand, the antenna can be manufactured independently other elements of the timepiece. Else apart, the antenna can be easily housed in this timepiece when assembled so as to take advantage of the inherent dimensions of the room to optimize the electrical dimensions of the antenna.

According to one embodiment of the invention, the part also includes a ground plane located in the mounting groove, between the antenna and the surface outside of the first case so that it surrounds this housing.

Thus, the antenna can be electrically isolated from disruptive elements that is found inside the timepiece.

la figure 1 montre un poignet portant une pièce d'horlogerie selon la présente invention;

la figure 2 est une vue en plan de la pièce d'horlogerie de la figure 1;

la figure 3 est une vue en plan d'un premier mode de réalisation d'une antenne faisant partie de la pièce d'horlogerie de la figure 1;

la figure 4 est une vue en plan d'un deuxième mode de réalisation d'une antenne faisant partie de la pièce d'horlogerie de la figure 1;

la figure 5 est en vue en coupe de la pièce horlogerie de la figure 2;

la figure 6 est une vue en perspective de l'antenne de la figure 3 enroulée autour du premier boítier de la pièce d'horlogerie de la figure 5;

la figure 7 est une vue en plan d'un troisième mode de réalisation de l'antenne faisant partie de la pièce horlogerie de la figure 2;

la figure 8 est une vue en perspective de l'antenne de la figure 6 enroulée autour du premier boítier de la pièce d'horlogerie de la figure 5; et,

la figure 9 est une vue en plan d'un quatrième mode de réalisation de l'antenne faisant partie de la pièce horlogerie de la figure 2.

Other characteristics and advantages of the invention will appear more clearly on reading the detailed description which follows, taken with reference to the appended drawings, representing, by way of example, different embodiments of the timepiece of the invention and in which:

Figure 1 shows a wrist carrying a timepiece according to the present invention;

Figure 2 is a plan view of the timepiece of Figure 1;

Figure 3 is a plan view of a first embodiment of an antenna forming part of the timepiece of Figure 1;

Figure 4 is a plan view of a second embodiment of an antenna forming part of the timepiece of Figure 1;

Figure 5 is a sectional view of the timepiece of Figure 2;

Figure 6 is a perspective view of the antenna of Figure 3 wound around the first housing of the timepiece of Figure 5;

Figure 7 is a plan view of a third embodiment of the antenna forming part of the timepiece of Figure 2;

Figure 8 is a perspective view of the antenna of Figure 6 wound around the first housing of the timepiece of Figure 5; and,

FIG. 9 is a plan view of a fourth embodiment of the antenna forming part of the timepiece of FIG. 2.

Figure 1 schematically shows a forearm carrying a wristwatch 1 comprising a case 2 and a bracelet 3. To capture a field electromagnetic carrying radio messages, the box 2 contains an antenna 4.

Figure 2 is a plan view of the wristwatch 1 comprising the case 2, the bracelet 3 and the antenna 4. The wristwatch 1 further includes a case additional 5, which is arranged in the housing 2. A micro transceiver 6 is disposed in the housing 5 in addition to the time display units including in particular a movement 7, a dial 8, hands 9 and a battery 10. The micro transceiver 6 is connected to antenna 4 so that it receives or transmits messages using the latter and transforms then these messages in data perceptible by the wearer of wristwatch 1, for example, by transmitting sound signals.

Referring now to Figure 3, we see that antenna 4 includes circuit conductive elements prints 11 and 12 fixed on a dielectric substrate 13. In addition, to facilitate the assembly of the antenna in the timepiece of the invention, the substrate 13 is flexible preference. For example, it has been determined that commercially available Kapton® and Espanex® materials are suitable in this regard.

The conductive element 11 defines a dipole. Of preferably, this dipole has a length of about λ / 2, where λ is the wavelength of the electromagnetic signal that the antenna is intended to receive or transmit. The element conductor 12 forms a compensation arm which is added to this dipole. The arm length is adjusted from so that the antenna impedance is adapted to a line of transmission which connects the antenna 1 to the micro transceiver 6 arranged in the room housing of the invention.

The connection between antenna 4 and this line of transmission is assigned to two excitation points 14 and 15, respectively at mid-length of the conductive element 11 and on the conductive element 12. The elements conductors 11 and 12 preferably consist of metallic deposits, for example, of copper, on the dielectric substrate 13.

Figure 4 shows a variant of the antenna of the Figure 3. We can see in this figure that the antenna 16 includes conductive elements in printed circuit 17.1 and 17.2 fixed on a dielectric substrate 18.

The conductive element 17.1 forms a dipole. Of preferably, this dipole has a length of approximately λ / 2. The conductive element 17.2 forms a compensation arm which is added to this dipole. A frame of a capacitor 19 is connected with the end of the element conductor 17.2 so as to form with the latter a gamma matching connection between dipole 17.1 and the transmission line connecting antenna 1 to microreceptor 6. The connection between the antenna 16 and the transmission line is assigned to two points excitation, respectively at mid-length of the element conductor 17.1 and the other armature of the capacitor 19.

Figure 5 is a sectional view of the wristwatch 1. Timepiece 1 includes the antenna dipole 4 of Figure 3 and the two boxes 2 and 5, the clockwork movement 7, the microreceptor 6 and the power stack 10 of Figure 2. The part 1 also includes a circuit board printed 20 mounted in the housing 5, a mirror 21, a bottom 22 and a transmission line 23. The micro transceiver 6 is mounted on the printed circuit board 20. The micro transceiver 6 and the movement 7 are powered by portable power source 10.

The case 2 is intended to receive the case 5 of so that the outer surface of the housing 5 and the inner surface of the housing 2 define a groove of mounting 25. As can be seen in FIG. 6, the antenna 4 is located in the mounting groove 25 so that it wraps around the housing 5.

The arrangement which has just been described makes it possible to manufacture the antenna independently of the other elements of the timepiece. This facilitates non-manufacturing only from the antenna but also from the room of watchmaking as such.

In addition, this arrangement facilitates the housing of the antenna when assembled in the room of watchmaking so as to take advantage of the dimensions inherent in the latter and to be able to optimize the electrical dimensions of the antenna.

Preferably, and as seen in Figures 3, 4 and 5, the surface of the conductive elements 11 and 12 extend in the depth direction of the wristwatch 1, namely in the direction between its glass and its background. However, the optimization of the antenna 4 is linked to this area. The depth of a wristwatch is a dimension which can be relatively easily changed without significantly affecting its visual appearance nor the ease of use. So the layout of the antenna this way helps facilitate optimization of the antenna in a wristwatch.

The antenna 4 is energized using the line of transmission 23 which connects the antenna 4 to the microreceptor 6. The transmission line 23 is preferably made up of a microstrip track. As an alternative, this line of transmission could also consist of a cable coaxial.

Preferably, the transmission line 23 goes to through an opening 26 formed in the side wall of the case 5. By bringing the microreceptor 6 closer to the antenna 4, this arrangement makes it possible to minimize the length of the transmission line 23 and thus minimize losses due to it.

Wristwatch 1 could also include a ground plane 24. The ground plane 24 is located in the mounting groove 25 between the antenna 4 and the surface exterior of the housing 5 so that it surrounds this latest. The ground plane 24 has the advantage of isolating electrically the antenna 4 of the disturbing elements which are inside the wristwatch 1, for example, metallic masses such as movement 7, the microreceptor 6 and the supply battery 10. Thus, the characteristics of the antenna 4 can be selected without considering disruptive effects from inside the wrist watch 1. One of the advantages of such an arrangement is that it allows using the same antenna with different movements watchmakers.

Figure 7 shows a third embodiment of the antenna of the timepiece of the invention. This antenna 30 consists of a conductive element in printed circuit 31 fixed on a dielectric substrate 32. As described above, the substrate 32 is, preferably made of a flexible material. The element conductor 31 is preferably produced by a deposit metallic on the dielectric substrate 32.

A radiant slot 33 is formed in the element driver 31. A person skilled in the art knows that, according to the Babinet principle, this antenna is the dual of a conventional dipole antenna, such as the dipole formed by the conductive element 11. Thus, the radiating slot 33 forms the complement of a dipole. Preferably, the slot has a length of about λ / 2, where λ is the length wave of the electromagnetic signal that the antenna is intended to capture.

The connection between the antenna 30 and the line of transmission 23 is assigned at two excitation points 34 and 35, mid-length and sides respectively opposite of the radiant slot 33. If necessary, the adaptation of the antenna 30 to the impedance of the line of transmission 23 can be done using a capacitor connected between one of the excitation points and one of transmission line conductors 23.

As seen in Figure 8, the antenna 30 is also located in the mounting groove 25 so that it is wrapped around the housing 5.

Figure 8 shows a fourth embodiment of the antenna of the timepiece of the invention. Of same as the antenna 30, the antenna 40 consists of an element conductor 41 fixed on a dielectric substrate 42. This the latter is preferably made of a material flexible. The conductive element 41 is preferably produced by a metallic deposit on the substrate 32, and defined by, a radiant slot 43 is formed in the ground plane 41. While the slot 33 is rectilinear, the slot 43 of Figure 6 has the shape of a "V".

The connection between the antenna 40 and the transmission line 23 is assigned at two excitation points 44 and 45 at opposite sides of the point of the "V" of the radiating slot 43. The adaptation of the antenna 40 to the impedance of the transmission line 23 could also be done using a capacitor connected between one of the excitation points and a wire of the transmission line 23.
Such a form of slot makes it possible to position the excitation points 44 and 45 in the direction of the depth of the wristwatch 1 so that they are opposite the microreceptor 6. Thus, the length of the line of light can be minimized. transmission which connects the antenna 40 to the microreceptor 6.

Finally, it should be noted that several modifications and / or improvements can be made to the system identification of objects according to the invention without departing from the part of it.

Claims (6)

1. Horlogical piece intended to be worn on the wrist, said piece including either a dipole antenna (4) or a radiating slot antenna (30; 40) able to receiver and/or emit an electromagnetic field bearing radio diffused messages, and a first casing (5) comprising

   organs (7, 8, 10) for displaying the time of day,

   and

   a micro emitter-receiver (6) which receive or emit messages detected by the antenna (4; 30; 40),

   characterized in that it further comprises a second casing (2) intended to receive said first casing (5) such that the exterior surface of said first casing and the interior surface of said second casing define a mounting slot or space 25, in that said antenna (4; 30; 40) comprises a dielectric subtract (13; 33; 43), and at least one printed circuit conductive element (11, 12; 31; 41) fixed to said subtract (13; 33; 43) and which definds a radiating element of said antenna (4; 30; 40), and in that said antenna (4; 30; 40) is located in said mounting slot or space (25) such that it is wound around said first casing (5).
2. Horlogical piece according to claim 1, characterized in that it further comprises a ground plate (24) located in said mounting slot between said antenna and the exterior surface of said first casing such that it surrounds this latter.
3. Horlogical piece according to either claims 1 or 2, characterized in that said dielectric subtract (13; 33; 43) is constituted by a flexible material.
4. Horlogical piece according to anyone of the preceding claims, characterized in that the surface of said conductive elements extend in the direction of the depth of said piece.
5. Horlogical piece according to anyone of the preceding claims, characterized in that it further comprises a transmission line (23) which connects said antenna (4; 30; 40) to said micro emitter-receiver (6), in that said first casing (5) includes an opening in its lateral wall, said transmission line (23) passing through said opening (26) to enable the approaching of said antenna (4; 30; 40) to said micro emitter-receiver (6)
6. Horlogical piece according to claim 5, characterized in that said antenna (16) is constituted by two conductive elements (17.1, 17.2) and a capacitor (19) connected to a first of said conductive elements so as to form a gamma adaptation connection between the second of said conductive elements and said transmission line (23).

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