EP1748331B1 - Electronic diver's watch with a redundant analog display of the instantaneous depth - Google Patents

Description

The present invention relates to an electronic watch having functions dedicated to the practice of diving.

More particularly, the electronic diving watch according to the present invention is of the type comprising a sealed case containing a watch movement which is surmounted by a dial provided with at least a first and a second coaxial needle, each needle being driven independently by a associated motor, of the type in which the watch movement comprises an electronic circuit which controls the first and the second hands according to a first operating mode in which each hand indicates a separate datum and according to a second mode of operation, said dive mode, in which at least the first needle indicates an instantaneous depth value.

Such a type of watch is described for example in the document EP 1 396 766 as well as in the document EP 1396767 . In this type of watch, where the display of the instantaneous depth is achieved by a needle, a watchmaker-type stepper motor, called the Lavet motor, is generally used to drive the needle in rotation about its axis. However, it happens that the watch loses engine pitches, for example following shocks to the watch, that is to say that there is a shift of pitch between the electronic counter and the angular position of the watch. 'needle. This phenomenon leads to a desynchronization between the motor and the control electronics, thus an erroneous display of the instantaneous depth by the needle.

The indication of instantaneous depth is vital for a diver. Therefore, such desynchronization can endanger his health because he will perform his dive based on erroneous data, which may lead him to exceed his physiological limits.

The present invention aims to overcome these disadvantages.

For this purpose, the invention provides a watch as defined in claim 1.

Thus, the two needles superimposed indicate the instantaneous depth. There is therefore a redundancy of the display concerning the instantaneous depth, which makes it possible to recognize false information. However, for the diver, false information is more serious than a lack of information. Indeed, in case of lack of information, the diver knows that he must stop his dive or obtain the information by other means, for example by means of the diving instrument worn by another diver who accompanies it.

With the watch according to the invention, if a step shift occurs for a needle, the diver notes from the beginning of the dive mode that the two needles are no longer superimposed for the instantaneous depth display, which allows it to detect the malfunction.

• le premier mode de fonctionnement est un mode horaire dans lequel la première et la seconde aiguilles affichent l'heure courante ;
• il est prévu un troisième mode de fonctionnement, dit mode synchronisation, dans lequel le circuit électronique commande l'alignement radial de la première et de la seconde aiguilles dans une position angulaire déterminée ;
• la montre comporte une troisième aiguille et, en mode plongée, la troisième aiguille est commandée de manière à indiquer une donnée distincte de la profondeur instantanée ;
• la profondeur instantanée est déterminée à partir des mesures effectuées par un capteur de pression.

According to other features of the invention:

• the first mode of operation is a time mode in which the first and second hands display the current time;
• there is provided a third mode of operation, said synchronization mode, wherein the electronic circuit controls the radial alignment of the first and second hands in a specific angular position;
• the watch has a third hand and, in dive mode, the third hand is controlled to indicate a datum distinct from the instantaneous depth;
• the instantaneous depth is determined from the measurements made by a pressure sensor.

• la figure 1 est une vue de face qui représente schématiquement une montre électronique de plongée conforme aux enseignements de l'invention en mode horaire
• la figure 2 est une vue similaire à celle de la figure 1 qui représente la montre en mode plongée ; et
• la figure 3 est un diagramme schématique qui représente le mouvement horloger de la montre de plongée selon la présente invention.

Other features and advantages of the present invention will appear more clearly on reading the detailed description which follows, made with reference to the accompanying drawings given by way of non-limiting example and in which:

• the figure 1 is a front view which schematically shows an electronic diving watch according to the teachings of the invention in time mode
• the figure 2 is a view similar to that of the figure 1 which represents the watch in dive mode; and
• the figure 3 is a schematic diagram showing the watch movement of the diving watch according to the present invention.

The figure 1 represents an electronic diving watch 10 according to the teachings of the invention. The watch 10 comprises a sealed housing 12 which may, for example, be of the molded bottom-middle type of plastic, comprising horns 14 provided for the attachment of a bracelet (not shown) and containing in particular a watch movement 15 (shown in FIG. on the figure 3 ), a dial 16, a first hand called hour hand 18 and a second hand called minute hand 20.

The needles 18, 20 are coaxial and are rotated about a central axis A1.

The housing 12 is closed on its upper face by an ice 22 carrying a fixed bezel 24 on its periphery. The telescope 24 carries minute graduations 26 ranging from a first indication of five minutes to a last indication of sixty minutes, two successive graduations being spaced five minutes apart.

The watch 10 comprises a control member 28, for example a crown rod that can be used as a pusher in addition to its conventional use in rotation.

As shown on the figure 3 the watch movement 15 comprises an electronic control circuit 30 which controls the angular position of the two hands 18, 20 respectively via two associated motors 32, 34 step-by-step. Preferably, the two motors 32, 34 are clock-type electric motors that allow the driving of each needle 18, 20 in both directions of rotation.

The watch movement 15 also comprises a pressure sensor 36 making it possible to measure at each instant the pressure of the environment outside the watch 10 and to convert this latter value into an instantaneous depth value Pi in the context of a dive. These techniques have been described in many documents of the prior art and will not be discussed in more detail later.

Thus, by a suitable programming of the electronic circuit 30 of the watch 10, there is provided a first mode of operation, here a time mode in which the two hands 18, 20 display the current time, as illustrated by the figure 1 and a second mode of operation, said dive mode, in which the two needles 18, 20 display information relating to the dive.

Manual and / or automatic selection means are provided for effecting a change of operating mode, in particular for switching from the time mode to the diving mode, when a dive starts, and vice versa when the wearer of the watch 10 resurfaces. The manual selection means may be constituted by the control member 28 and the automatic selection means may be constituted by the electronic circuit 30 coupled to a detection device 38 which detects the presence of water outside the housing 12 .

These selection means being part of the state of the art, they will not be discussed further in the present patent application, insofar as they do not constitute the heart of the present invention and where the skilled person will not meet no particular difficulty to implement them.

According to the teachings of the invention, in the dive mode, the two needles 18, 20 are used to simultaneously indicate the value of the instantaneous depth Pi, as a function of the signals emitted by the pressure sensor 36, the two needles 18, 20 being aligned radially on the same side of the axis A1.

Thus, when the plunger enters the water, which activates the dive mode, the two needles 18 and 20 are positioned opposite the indication corresponding to twelve hours and zero depth, that is to say opposite the indication sixty minutes carried by the telescope 24. When the plunger descends, the two needles 18, 20 begin to rotate simultaneously in the clockwise direction to indicate the value of the instantaneous depth Pi opposite the graduations of minutes 26. Similarly, when the plunger rises, the two needles 18, 20 rotate simultaneously in the counterclockwise direction.

On the figure 2 the watch 10 is shown in dive mode and the instantaneous depth Pi indicated by the hands 18, 20 is the value ten. The hour hand 18 is shown in broken lines because it is located under the minute hand 20 in solid lines. Of course, the dial 16 may be provided with a graduation representative of the instantaneous depth Pi, replacing or in addition to the graduations carried by the telescope 24. The scale of the instantaneous depth indication Pi may vary and the unit The display may vary, the depth being indicated for example in meters or feet.

It should be noted that, in normal operation, in dive mode, the plunger sees here a single needle (the minute hand 20), which facilitates the reading of the instantaneous depth Pi. Furthermore, the graduations 26 used for the reading of the instantaneous depth Pi being the same as those used for the indication of minutes, the housing 12 of the watch 10 is not overloaded with useless indications further facilitating the accessibility of the information provided.

In the case of a loss of pitch on one of the two motors 32, 34, for example following a shock, the two needles 18, 20 are angularly offset relative to each other, when of the display of the instant depth Pi in dive mode, which is shown in dashed line on the figure 2 . The diver then visualizes the existence of a malfunction in the display of the instantaneous depth Pi, so that he can react accordingly.

Advantageously, an additional mode of operation, called synchronization mode, is provided for synchronizing the angular position of each hand 18, 20 with the control signals of the electronic circuit 30, so as to allow correction of the angular phase shift between the hands 18, 20 in dive mode. According to this synchronization mode, the electronic circuit 30 controls the radial alignment of the two needles 18, 20, for example facing the midday position, and the user corrects the angular offset of the needles 18, 20 relative to the midday position by actuating the control member adequately.

Of course, additional functionalities may be provided on the diving watch 10, for example a dives history function with storage means (not shown) integrated in the electronic circuit 30, or means for displaying additional data on diving such as the remaining dive time before a decompression stop is required, etc. The data relating to these additional functionalities can be displayed by means of an analog display, for example by means of a third hand (not shown) which displays the seconds in time mode, or by means of a digital display, for example a liquid crystal screen (not shown).

According to the embodiment described and shown, the first mode of operation is a time mode. According to an alternative embodiment (not shown), the two needles 18, 20 indicate different data other than the current time, in the first mode of operation, for example the date. The current time is then displayed by other means, analog or digital.

Claims (5)

1. Electronic dive watch (10) including a water resistant case (12) containing a watch movement (15) on which there is mounted a dial (16) provided with at least one first and one second coaxial hand (18, 20), each hand (18, 20) being driven independently by an associated motor (32, 34), of the type wherein the watch movement (15) includes an electronic circuit (30) that controls the first and second hands (18, 20) in accordance with a first operating mode in which each hand (18, 20) indicates a distinct item of data and in accordance with a second operating mode, called the dive mode, in which at least the first hand (18, 20) indicates an instantaneous depth value (Pi),
   characterized in that, in the dive mode, the first and second hands (18, 20) are controlled such that they simultaneously indicate the same instantaneous depth value (Pi), both hands (18, 20) rotating simultaneously in the same direction when the instantaneous depth (Pi) changes.
2. Electronic watch (10) according to the preceding claim, characterized in that the first operating mode is a time mode in which the first and second hands (18, 20) indicate the current time.
3. Electronic watch (10) according to claim 1 or 2, characterized in that a third operating mode, called the synchronisation mode, is provided, in which the electronic circuit (30) aligns the first and second hands (18, 20) radially in a determined angular position.
4. Electronic watch (10) according to any of the preceding claims, characterized in that the watch includes a third hand and in that, in the dive mode, the third hand is made to indicate a data item distinct from the instantaneous depth (Pi).
5. Electronic watch (10) according to any of the preceding claims, characterized in that the instantaneous depth (Pi) is determined from measurements made by a pressure sensor (36).

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