Patent Application
20180173169
This application claims priority from European Patent Application No. 16205234.4 filed on Dec. 20, 2016; the entire disclosure of which is incorporated herein by reference
The invention relates to a device (for example a watch, a telephone, a remote control, etc.) provided with an actuation system making it possible to activate an electrical element of said device (the electrical element is for example an LED, an antenna for transmitting electromagnetic waves, timing means, etc.).
It is known practice to activate an electrical element of a device by actuating a pushbutton. For example, it is known practice to activate means for illuminating the dial of a watch by actuating a pushbutton located on the outside of the case, to activate an antenna for transmitting a remote control command via a remote control button for example in order to control an audiovisual device or a lamp. The actuation of the pushbutton causes electrical contact to be made between an energy source (generally a battery) and the electrical element (a light source, generally a light-emitting diode, an infrared optical or radiofrequency transmission element, etc.).
However, this system requires the use of an exhaustible electrical energy source (the battery).
The aim of the present invention is to overcome the aforementioned drawback.
To this end, the invention relates to a device comprising:
a housing having a cavity that is open to the exterior of the housing
an electrical element positioned inside the housing
an actuation system for actuating the electrical element, comprising:
The first plate is initially at the temperature of the surroundings of the device, and the second plate is initially at the temperature of the housing since it is positioned against a wall of the cavity of the housing. When the first plate is warmed up, for example through the transmission of the natural warmth given off by a finger placed on the first plate, by rubbing the finger on the first plate, or by actuating an intermediate plate that itself creates friction with the first plate, a difference in temperature between the first and the second plate arises. The temperature gradient results in a difference in electrical potential, via the Seebeck effect, between the terminal blocks of the first plate and the terminal blocks of the second plate. This difference in electrical potential is subsequently communicated to the electrical element via the electronic transmission circuit. The actuation system therefore behaves like a thermoelectric pushbutton that is without moving parts, is completely sealed and can be used for both mechanical watches and electronic watches.
It should be noted that using a converter placed at the output of the thermoelectric element and capable of converting voltages of the order of millivolts into voltages of the order of volts, if the device is located in surroundings at a temperature that is lower than that of the human body, just the contact of a finger with the first plate is enough to generate electrical power that is sufficient to produce visible light using a light-emitting diode. However, if the device is worn on the body or is located in surroundings at a temperature that is higher than that of the human body, it is necessary to rub the first plate in order to generate such power.
In accordance with advantageous embodiments of the invention, the device may have the following features, taken alone or in any technically feasible combination.
In one non-limiting embodiment, the first plate consists of or includes a layer consisting of a material having a high coefficient of friction.
In one non-limiting embodiment, the electronic transmission circuit includes a DC-to-DC converter and two electrical wires passing through the housing, each wire being linked both to a terminal block of the second plate and to said converter.
In one non-limiting embodiment, the electronic transmission circuit includes an accumulator that is placed at the output of the DC-to-DC converter, and a control unit that is connected both to the accumulator and to the electrical element for the purpose of discharging the accumulator when its charge exceeds a threshold value.
In one non-limiting embodiment, the accumulator is a capacitor.
In one non-limiting embodiment, the actuation system includes an electric insulator layer that is positioned between the first plate and the second plate and laterally covers the thermoelectric module.
In one non-limiting embodiment, the actuation system includes an intermediate plate and means for moving the intermediate plate against the first plate.
In one non-limiting embodiment, the device is a wristwatch.
In one non-limiting embodiment, the device is a remote control.
In one non-limiting embodiment, the device is a wireless wall switch.
In one non-limiting embodiment, the electrical element includes a light-emitting diode.
In one non-limiting embodiment, the electrical element includes a radiofrequency transmitter.
Other particularities and advantages will become clearly apparent from the description thereof provided below by way of completely non-limiting indication and with reference to the appended drawings, in which:
The watch AP bears an actuation system SA (shown in
The thermoelectric module MT is positioned in a cavity CV that is made in the lateral area of the housing BT and is open to the exterior of the housing BT, i.e. the external portion of the watch AP. In a known and conventional manner, the thermoelectric module MT includes first P1 and second P2 electrically insulating plates. The first plate P1 bears a plurality of electrically conductive terminal blocks SM that are positioned one next to the other. Similarly, the second plate P2 bears a plurality of electrically conductive terminal blocks SM that are positioned one next to the other. Each terminal block of the first plate P1 is linked to two terminal blocks of the second plate P2 by a pair of semiconductive pillars PL so as to take as full advantage as possible of the Seebeck effect. Each pair of pillars PL includes an n-doped semiconductor and a p-doped semiconductor. The first plate P1 and the second plate P2 extend substantially in parallel to one another, and the pillars PL extend substantially orthogonally to the plates P1, P2.
The second plate P2, forming the cold pole of the thermoelectric module MT, is positioned against the bottom FD of the cavity CV. The first plate P1, facing the second plate P2, is therefore accessible from outside the housing BT. The first plate P1 forms the warm pole of the thermoelectric module MT. Applying a temperature gradient through the thermoelectric module, by warming the first plate P1, leads to the diffusion of charge carriers towards the second plate P2, which then generates a voltage. The actuation system SA also includes a thermal insulator layer IS that is positioned all around the thermoelectric module MT, between the first and the second plates P1, P2.
The first plate P1 is for example warmed up by rubbing it with a finger, as shown in
In one alternative embodiment, the actuation system SA includes an intermediate plate and means for moving the intermediate plate against the first plate P1, for example springs. A user then does not have to touch or rub the first plate P1, which has a high coefficient of friction and is therefore not pleasing to the touch, but only has to move the intermediate plate, which itself will rub against the first plate P1. The intermediate plate is advantageously made of a material that is pleasing to the touch, for improved user comfort.
With reference to
Of course, the present invention is not limited to the illustrated example has the potential for various alternative embodiments and modifications that will be apparent to those skilled in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 16205234.4 | Dec 2016 | EP | regional |
