This invention concerns a timepiece having at least an analog display means in which the hands are located between a dial and a crystal, the latter bearing on its inner surface a metallized decoration, partially extending thereover in order to support an electro-acoustic transducer, and to assure an electrical connection with a first electrode of said transducer. A printed circuit located within a timepiece movement provides an electronic control means and output terminals for an electric signal at an acoustic frequency and electrical couplings comprising two conductive leads are arranged so that the first thereof contacts said metallized decoration and the second thereof contacts a second electrode of said transducer.
Timepieces are known in which the alarm arrangement takes the form of an electro-acoustic transducer operatively associated with the watch crystal. Generally this may take the form of a piezoelectric pellet glued onto the internal surface of the crystal and which receives an acoustic frequency signal coming from the watch electronics. For example the Japanese Utility Model No. 1 223 023 describes an electric alarm clock which includes a piezoelectric slab fixed to the internal surface of the crystal. The slab oscillates at an audible frequency in view of the signal emitted by a circuit disposed within the case. The slab in turn excites the crystal into vibration. In the document cited the slab is found in the centre of the crystal and its connection to the internal circuit is realised by means of two wires which initially traverse the crystal then penetrate to the interior of the watch by a hole arranged at the periphery of the dial.
It can be foreseen that this type of construction may cause difficulties for the encasing of the timepiece. Effectively after having mounted the dial and set the hands in place it becomes necessary to connect the slab to the feed wires by means of soldering or by conductive glue, this requiring specially trained personnel.
The present invention overcomes this difficulty by proposing an arrangement wherein soldering or use of conductive glue is avoided in connecting the slab to its feed source, thereby greatly facilitating the encasing of the watch.
A watch similar to the generic definition given hereinabove is described in Japanese Patent Specification No. 54-59 968. However, in this case the disclosure concerns a digital display thus not providing a dial interposed between the module and the watch crystal, and wherein the problem does not exist of having to add contact blades to electric leads following assembly of the dial onto the movement as described hereinafter.
This invention thus has as its purpose to provide in a timepiece having a mechanical analog display, connection means between the electronic module and the electro-acoustic transducer, such means being defined by the claims.