EP2075654A1 - Portable electronic device designed to display the value of variables based on measurements taken by a sensor and having a history function - Google Patents

Abstract

The device has a controller circuit (21) and a resonator (22) provided in time, acquisition and history modes. Memory zones (25, 26) e.g. RAM and stable memory, stores instantaneous values along given periodicity, in the acquisition mode. The circuit and the resonator parallely display chronological series of values in preset time interval based on the stored values in the history mode. One series directly represent values taken by measurement of physical magnitude in the acquisition mode, and another series is calculated from the stored values and represent time variation in the measurement. An independent claim is also included for a method for displaying a history for a portable electronic device.

Description

Technical area

The present invention relates to a portable electronic device comprising a case containing a watch movement surmounted by a display, said watch movement comprising electronic circuits capable of producing time signals intended for control means of said display, said electronic circuits being provided for being selectively in one or more of a plurality of modes of operation, said plurality of modes of operation including a first mode, said time mode, wherein said display is provided to indicate the time.

The electronic device according to the invention further comprises a sensor provided for performing a measurement of a physical quantity and for renewing said measurement with a given frequency. In a second mode of operation, called acquisition mode, the display is provided to provide a first indication representative of the current value of said measurement, and a second indication representative of a variation in time of said measurement. The electronic device further comprises storage means provided for, in said acquisition mode, recording at a given periodicity a succession of values each corresponding to an instantaneous value of said current value.

State of the art

The patent application published under the number WO 2005/096106 A1 , in the name of the Applicant, discloses an electronic device in which analog display members are controlled to display the current time, in a first operating mode, and to each display the value of a variable based on the measurement of a physical quantity effected by a sensor of the device, in a second mode of operation.

The patent application published under the number WO 2005/096105 A1 , also in the name of the Applicant, discloses an electronic device in which analog display members are controlled to display the current time, in a first mode of operation, and to respectively display the measurement of a time interval and the instantaneous depth, calculated from pressure measurements made by a sensor of the device. This document provides that the electronic device comprises storage means for storing values of the measured pressure to allow a reproduction of the behavior that the display members have exhibited during the measurements, in a third mode of operation called historical mode, the reproduction being based on the stored values.

The storage of a series of values associated with a variable measured by a sensor enabling the implementation of a historical mode raises memory management problems in the case of a portable device. These problems become critical when it comes to memorizing several series of values associated with one or more measured variables, in particular for issues of memory congestion and its power consumption.

A known solution to answer this problem is to increase the value of the storage period, in particular as a function of the total duration of the measurements. Such a solution, however, shows its limits when the duration of the measurements is very important since the representativity of the values stored in relation to the measured values suffers strongly.

Disclosure of the invention

A first object of the present invention is to overcome the above-mentioned drawbacks of the prior art by providing a portable electronic device allowing a visualization of the values of two variables as a function of time, these values being based on measurement results previously carried out on the basis of time. using a sensor, while optimizing the size of the memory provided in the device.

For this purpose, the invention provides in particular a portable electronic device of the type mentioned above characterized in that in a third mode, said historical mode, said electronic circuits are provided for, on the basis of said succession of recorded values, to make simultaneously displaying, in a predetermined time interval, two chronological sequences of values, a first of said sequences being directly representative of the values taken by said measurement in said acquisition mode, and the other of said sequences being calculated from said succession of recorded values and being representative of the variation in time of said measurement.

The present invention also relates to a method of displaying a history on a device of this type.

Thanks to these characteristics, only one series of values can be stored, the second series of values, corresponding to the values representative of the variation in the time of the measurement (or the measured physical quantity), being calculated each time it must be displayed. Thus, this series of values is calculated, on the one hand, during the course of the second mode of operation, when the measurements of the physical quantity are acquired by the sensor and, on the other hand, during the display of the history when the measured values which have been memorized are recalled.

According to one variant, the electronic circuits also store the duration during which the acquisition mode has remained active or, alternatively, the value of the period defining the periodicity according to which the storage means record the current value of the measurement. variant is a preferred embodiment especially if the period does not have a single value defined by the manufacturer but depends, on the contrary, the conditions of use of the electronic device.

Advantageously, it is expected that the progress of the display of the history can be interrupted and possibly resumed under the effect of predefined actions of a user. In addition, it is preferably provided that the electronic circuits of the device are also arranged to make a jump in the flow of the historical mode, in response to an action of a user, to control the analog display members so that they pass displaying a first value associated with a first stored value Pi on displaying a second value associated with a second stored value Pj located chronologically before or after the first stored value Pi and spaced in time from the latter more than once the value of the storage period.

In the latter case, it is advantageously provided that the value representative of the variation over time of the physical quantity associated with the value Pj is calculated at least on the basis of the stored values Pj and Pj _-1 .

In a non-limiting manner, the sensor used is a pressure sensor for measuring altitude or depth, but it is understood that the invention can be implemented with other types sensor such as a temperature sensor or a magnetic field sensor for example.

Furthermore, a number of alternative embodiments can be provided, such as a specific display of the measured values during acquisition, an adaptation of the display scales in the historical mode according to the measured extremes, an automatic or manual activation. mode of acquisition, a plurality of memory areas each of which is dedicated to a series of special measurements, or the arrangement of at least one LCD screen on the dial to complete the analog display.

In addition, the electronic device according to the present invention could display other indications. In particular, the display could also provide a third indication representative of a variation in time of said second indication (i.e., an indication of the acceleration of the variation over time of the measurement).

Brief description of the drawings

• la figure 1 représente une vue de face d'un dispositif électronique portable selon un premier mode de réalisation de la présente invention, réalisé sous la forme d'une montre de plongée disposant de moyens pour afficher la valeur d'une profondeur et la valeur de la composante verticale de la vitesse
• la figure 2 représente un diagramme schématique général du circuit électronique du dispositif indicateur représenté sur la figure 1, et
• la figure 3 représente un diagramme schématique sur lequel sont portées, d'une part, des courbes représentatives des mesures effectuées et des mesures enregistrées correspondant à la profondeur et, d'autre par, des courbes représentatives des calculs effectués pour déterminer la vitesse de variation de la profondeur dans deux modes de fonctionnement différents de la montre de la figure 1.

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 examples and in which:

• the figure 1 represents a front view of a portable electronic device according to a first embodiment of the present invention, made in the form of a diving watch having means for displaying the value of a depth and the value of the vertical component speed
• the figure 2 represents a general schematic diagram of the electronic circuit of the indicator device shown in FIG. figure 1 , and
• the figure 3 represents a schematic diagram on which are shown, on the one hand, representative curves of the measurements made and recorded measurements corresponding to the depth and, moreover, by curves representative of the calculations made to determine the speed of variation of the depth in two different modes of operation of the watch of the figure 1 .

Mode (s) of realization of the invention

The figure 1 represents a preferred embodiment of the portable electronic device according to the present invention, in the form of a diving watch, very simple both from the structural point of view and from the point of view of its operation. The watch 1 is in appearance as a watch of conventional type. This comprises, in fact, a housing 2 which may be, for example, metal screwed bottom, comprising horns (not shown) provided for the attachment of a bracelet (not shown) and containing in particular a watch movement (no represented), a dial 4 and closed on its upper face by an ice, carrying a fixed bezel 6 on its periphery. The watch 1 further comprises three control members of the traditional type, namely two pushers 7 and 8 and a crown-setting rod 9.

Note that the dive watch 1 is preferably provided with a touch screen, that is to say that it is covered with capacitive electrodes, alternatively or in addition to the pushers 7 and 8, without departing from the scope of FIG. the present invention.

The telescope 6 carries first graduations of depth 10 variable scale extending from a first indication of 0 meters, located at noon, until a last indication of 50 meters, arranged at eleven o'clock.

The dial 4 carries second circular graduations 12, the unit of which is the meter / minute, subdivided into two zones. The first zone 13 extends, in the clockwise direction, from the position corresponding to the graduation of 20 meters at eight o'clock to the position corresponding to the graduation of 30 meters at nine o'clock. The second zone 14 extends, in the clockwise direction, from the end of the first zone 13 to the position corresponding to the 0 meter graduation. The graduations of the second zone 14 correspond to an ascending speed scale and extend between 0m / min and 30m / min, while the first zone corresponds to negative climbing speeds and has no scale.

The watch 1 also comprises two hands, respectively, for indicating the hours 16 and minutes 17.

The dial 4 furthermore has a window through which a liquid crystal display (LCD) 18 is made visible.

The watch 1 comprises particular technical means, which will be described briefly later in connection with the figure 2 , allowing him to provide specific indications relating to the practice of diving. These technical means include a pressure sensor provided for measuring the ambient pressure and to repeat this measurement at close intervals, and electronic circuits for converting the values taken by this measurement into depths in the context of the 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 of the watch according to the present invention, there is provided a first mode of operation, or time mode, wherein the conventional functions are provided by the hour and minute hands. In addition, the crown rod 9 has two stable positions, a first stable position being the rest position in which the stem crown does not perform any function. Conventionally, the second stable position is a position pulled relative to the rest position, in which the crown rod allows to adjust, by rotation, the indication of the time provided by the two needles 16, 17.

Conventional means are advantageously provided for effecting an automatic change of operating mode, in particular for switching from the time mode to a second operating mode, called the dive mode, when a dive starts. These means allow conversely to return to the time mode, automatically, from the dive mode when the diver, wearing the watch, resurfaced. Such means are for example described in the application WO 2005/096105 A1 already mentioned.

Once the dive mode is activated, the functions respectively associated with the minute hands 17 and hours 16 are the display of the instantaneous depth and the display of the rate of climb.

Of course, it is possible to provide manual means for activating the dive mode additionally or alternatively with respect to the automatic activation.

These 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 person skilled in the art will not encounter any problem. particular difficulty to implement them.

According to the present invention, the diving watch 1 comprises a third mode of operation, called historic mode, preferably activated by an action of the user, for example by means of a pressure on the crown rod 9 followed by a selection made by a contact on the touch screen.

For the implementation of the historical mode, means are provided for controlling the hands of the hours 16 and minutes 17, so that they exhibit a behavior representative of the course of the dive in relation to which data have been stored.

Several variants of implementation of the historical mode can be provided. Since a dive can last several tens of minutes, it is preferable to control the needles 16 and 17 in such a way that they substantially reproduce their respective past behaviors with an accelerated speed with respect to the acquisition speed of the measurements. Those skilled in the art may define acceleration parameters that suit their own needs and program the electronic circuit of the watch accordingly, without departing from the scope of the present invention. For example, it is possible to divide by 60 the total duration of the dive to be displayed, so that ten minutes of diving are reproduced in ten seconds in the historical mode.

A possible variant of implementation of the history from the point of view of the speed of reproduction consists in reproducing any dive carried out, whatever the duration, in a time window predefined by the manufacturer of the watch. The time window can be defined with a fixed length or with a variable length, between two extreme values. For example, it can be provided that the duration of the history is set at 30 seconds, the movement of the needles 16 and 17 being then adapted to reduce the effective duration of the dive to 30 seconds. It is also possible, alternatively, that the duration of the history is between 15 and 30 seconds in particular depending on the effective duration of the dive to reproduce.

Other variants and details of implementation of the historical mode are presented, without limitation, in the application WO 2005/096105 A1 .

The figure 2 is a schematic diagram of the general structure of the electronic circuit of the diving watch according to the present invention.

In general, the electronic circuit of the watch includes an integrated circuit 20 including a controller circuit 21 capable of managing the conventional time functions of the watch 1 comprising, for this purpose, a time division circuit and connected in particular to a resonator 22 providing a time base. From this time base, time information is produced by the controller circuit 21, in particular to provide the functions of the time mode and the functions relating to the diving mode.

In addition, the controller circuit 21 receives as input signals generated by a pressure sensor 23 generating analog electrical signals representative of the surrounding pressure. These signals pass through an analog-digital converter 24 before being supplied to the input of the controller circuit 21, in the form of a digital signal.

The pressure sensor 23 is of conventional type and the skilled person will not encounter any particular difficulty to choose one that is suitable for the implementation of the present invention.

The integrated circuit 20 also includes memory zones, in particular a first memory zone 25, preferably of the non-volatile type, containing a program enabling the controller circuit 21 to perform calculations relating to the diving mode, such as, for example, the conversion of the measurements. pressure in depth values, in relation to a non-schematized volatile memory zone. The choice of a non-volatile reprogrammable memory (Flash or EPROM, for example) possibly makes it possible to update the calculation program later. The integrated circuit 20 preferably comprises at least a second memory zone 26, also of the non-volatile type, in which the measurements as well as the results of the calculations carried out by the control circuit 21 are stored periodically. This second memory zone 26 is in particular designed to store depth measurements. Thus, this information is consulted by the controller circuit 21, in particular when the watch is in the historical mode.

From these respective input signals, the controller circuit 21 determines the plunger's situation at each instant of a dive. The controller circuit 21 then sends signals adapted to a circuit of control 27 bi-directional motor means, for example two bi-directional motors, so that the hour hand 16 displays the speed of variation of the depth opposite the second graduations 12 of the dial. Similarly, the control circuit 21 produces signals adapted for the control circuit 27 of the motor means in such a way that the minute hand 17 displays the instantaneous depth at each instant of the dive, opposite the graduations 10 carried by the telescope 6 of the watch.

Furthermore, the electronic circuit of the watch comprises conventional means (not shown) for detecting pressures made by the user on the crown rod 9. The latter is in position A at rest and has two extreme positions B and C The unstable position B, obtained by user pressure activates a function of the controller circuit 21 modifying the operating mode of the watch, as described above. In a preferred manner, when the crown rod 9 is pressed into position B from the time mode, the control circuit 21 generates activation signals of the touch-sensitive glass 4. During a certain predefined duration, the user can then select a particular function by placing a finger on an area of the touch screen that he has selected.

It is thus possible to associate the activation of the historical mode with a predefined area of the touch screen.

For technical details relating to the operation of the touch screen, the reader may refer to the document EP 0 838 737 A1 , published on behalf of Asulab SA.

Of course, the skilled person is able to program as desired the integrated circuit 20 of the watch according to the present invention, to provide responses respectively adapted to different possible actions on the stem-crown 9 and / or on the ice touch 4.

In addition, conventional means well known to those skilled in the art are implemented to allow a correction of the current time indicated by the needles 16 and 17, in time mode, when the crown rod 9 is pulled into the position. stable C.

In addition, the integrated circuit 20 controls the display of the liquid crystal display 18 which makes it possible to complete the indications of the hour and minute hands by simultaneously displaying additional information. According to a preferred variant, the LCD display 18 is provided to indicate the actual duration of a dive, either in real time during the course thereof (acquisition mode), or in the historical mode. One could also, for example, plan to display the maximum depth reached during a dive.

Additional features may also be provided on the Dive Watch 1. Their nature and how to access it, except for the historical mode, will not be discussed in detail as they do not intervene directly in the dive. implementation of the present invention. Examples may be found in the international applications cited above, by way of non-limiting illustration.

From the operating point of view, when the diver enters the water, the watch activates the dive mode. The two needles 17 and 16 are initially positioned respectively opposite the indication corresponding to 0 meter, carried by the telescope 6 and, at nine o'clock, in other words opposite the indication 0m / min carried by the dial 4. When the diver descends, the minute hand 17 starts to turn clockwise to indicate the value of the instantaneous depth opposite the graduations 10. At the same time, the hour hand 16 moves, next to the seconds graduations 12, to indicate the value of the variation of the depth.

It will be noted that in the embodiment shown, the first zone 13 of the second graduations 12 does not carry a scale. Thus, Downhill speeds are not displayed accurately but only roughly. Such an embodiment is of course illustrative and the skilled person can use a different display, adapted to his own needs, without departing from the scope of the present invention.

It can advantageously be provided that the rate of change of the depth is calculated on the basis of an average made from several successive values of the depth. By way of nonlimiting illustrative example, the variation speed displayed during the dive mode by the hour hand 16 may be a sliding average of the last three instantaneous speeds, the latter being directly calculated on the basis of the measurements made by the sensor. pressure. It will be understood that in historical mode, this method of calculation can not be applied at the very first moment of the dive. In this case, the initially displayed speed may be artificially constant, to avoid the display of unrealistic values, due to the selected calculation algorithm, depending on the behavior of the user. It is possible to provide, for example, that the initial speed displayed is of the order of 10m / min during the first seconds of the dive.

The pressure sensor can be powered to perform one measurement per second. It is preferable to store each measurement in a specific memory area for at least the first three minutes. If the dive is an apnea that lasts less than three minutes, a sufficient number of measurements are stored to allow a reliable reproduction of the history of the dive.

When the dive lasts more than three minutes, the measurements are advantageously stored at a frequency lower than the measurement frequency of the pressure sensor. Such an arrangement makes it possible to limit the size of the necessary memory zone when the duration of the dive becomes greater, without significantly affecting the reproduction quality of the history. Preferably, recording a value of the pressure, or depth, with a period of the order of a few tens of seconds in a bottle dive, for example, every 30 seconds. In addition, it is expected that when the duration of the current dive reaches 3 minutes, according to the example provided above, a large part of the stored measurements is erased so as to free memory locations for subsequent measurements. In fact, it suffices to keep only measurements previously made at time intervals of a duration corresponding to the period for recording the bottle diving measurements, ie 30 seconds following the previously mentioned example.

If we consider the previous numerical example, given by way of illustration and not limitation, memorizing the first three minutes of a dive requires 180 memory locations, this number then being reduced to 6 when the duration of the dive exceeds 3 minutes. On the other hand, when the dive is prolonged, because of the lower frequency of the memorizations, it becomes possible to memorize the profile of the dive for a maximum duration of one hour and a half with such a number of memory locations, This is enough to meet the needs of a large majority of divers.

Requirement WO 2005/096105 A1 discloses an alternative embodiment defining a more gradual variation of the frequency of storing the results of the measurements. The skilled person may refer to this disclosure or any other known method adapted to optimize the memory management of the watch according to the invention.

To limit the memory space required for the storage of pressure measurements, the present invention proposes to limit the quantity of data to be stored. Thus, it is envisaged to memorize only a certain percentage of the values measured or as converted by the circuit integrated, according to the duration of the dive and as is apparent from the foregoing, and a value representative of the recording period of these measurements in the memory zone 26.

The representative value of the recording period may be the period itself or, alternatively, the total duration of the dive, the integrated circuit of the watch being programmed to unambiguously deduce the value of the recording period. corresponding.

The values of the speed of variation of the depth calculated during dive, for its part, are not memorized, which saves substantially half of the memory conventionally used in the devices in the prior art.

1. a) effectuer, dans un premier temps, une acquisition périodique de la valeur de la grandeur physique en fonction du temps, dans un second mode de fonctionnement du dispositif électronique,
2. b) mémoriser au moins une partie des valeurs mesurées, avec une période donnée, dans des moyens de mémorisation,
3. c) mémoriser une valeur représentative de cette période donnée dans les moyens de mémorisation.
   Le procédé selon l'invention se distingue des procédés de l'état de la technique par le fait qu'il comporte en outre, dans un troisième mode de fonctionnement dit mode historique, une étape ultérieure consistant à
4. d) effectuer un affichage chronologique représentatif des valeurs mémorisées de la grandeur physique en fonction du temps, au moins un premier des organes d'affichage analogique indiquant, en regard des graduations, la valeur d'une variable directement liée aux valeurs mémorisées, le second des organes d'affichage analogique étant commandé pour indiquer, en regard des graduations, la valeur d'une variable calculée à partir d'au moins deux des valeurs mémorisées.

In general, the present invention also relates to a method for displaying a history for a portable electronic device of the type described above, comprising in particular a sensor of a physical quantity and having a first hourly mode of operation, the method comprising the steps of:

1. a) performing, in a first step, a periodic acquisition of the value of the physical quantity as a function of time, in a second mode of operation of the electronic device,
2. b) storing at least a portion of the measured values, with a given period, in storage means,
3. c) storing a value representative of this given period in the storage means.
   The process according to the invention differs from the methods of the state of the art in that it also comprises, in a third mode of operation known as the historic mode, a subsequent step of
4. d) performing a representative chronological display of the stored values of the physical quantity as a function of time, at least a first of the analog display members indicating, in relation to the graduations, the value of a variable directly related to the stored values, the second of the analog display members being controlled to indicate, next to the graduations, the value of a variable calculated from at least two of the stored values.

Thus, when the history mode is activated, the control circuit 21 controls the motor means so that, on the one hand, the minute hand 17 scans the first graduations to display depth values related to the stored measurements. On the other hand, the integrated circuit calculates, for each of the stored values associated with a displayed depth, a value of the speed of variation of the depth.

At the beginning of the historical mode run, as in the dive mode, the value displayed for the rate of change of the depth is preferably artificial. For example, it can be predicted to grow first before being computed on the basis of the first stored depth values.

dans laquelle Pi et Pi_-1 sont les valeurs respectives de la profondeur aux instants i et i_-1, Vi_-1 est la valeur de la vitesse de variation de la profondeur à l'instant i_-1 et T est la valeur de ladite période donnée.After a few moments, on the order of a few seconds, the rate of variation of the depth can be calculated as a sliding average of the instantaneous speed calculated between the last two depths read in memory and the average speed calculated last. In other words, the rate of variation of the depth Vi can be calculated by the following formula: $$V_i={}^{\left(\frac{P_i-P_{i-1}}{T}+V_{i-1}\right)}{/}_2$$

in which Pi and Pi _-1 are the respective values of the depth at instants i and i _-1 , Vi _-1 is the value of the rate of variation of the depth at time i _-1 and T is the value of said given period.

Alternatively or additionally, the speed Vi can be calculated by the following alternative formula: $$V_i=\frac{P_i-P_{i-1}}{T}$$

The integrated circuit may optionally be programmed in such a way that the first formula is used for short-duration dives, that is to say for example having a duration of less than fifteen minutes, while the second formula is used for dives. longer duration.
Another advantageous formula could be for example: $${\mathrm{V}}_{\mathrm{i}}=\frac{P_{i+1}-P_{i-1}}{2T}\mathrm{.}$$

This formula, usable in the historical mode only, has the advantage of minimizing the time difference between the depth and the rate of climb.

The present invention also provides the possibility of interrupting the operation of the historical mode in response to an action of a user on one of the external control members and, preferably, to resume it in response to a new action by the user on one of the external control devices.

In addition, the electronic circuits of the watch are preferably arranged to make a jump in the flow of the historical mode in response to an action of a user on one of the external control members. This leap in the unwinding results in a control of the analog display members so that the latter pass from the display of a first value associated with a first stored value Pi to the display of a second value associated with a second stored value Pj located chronologically before or after the first stored value Pi and spaced in time from the latter by more than one time value of the recording period. In parallel with this jump, the time displayed on the LCD 18 is modified accordingly.

For example, it can be expected that, during the unfolding of the historic mode, a pressure on the crown rod 9 causes an interruption of the unwinding while a pressure on the pusher 7 causes a jump forward of a predefined duration in the unfolding of the historical mode and, that a pressure on the pusher 8 causes a jump back of the same predefined duration in the history mode unfolding.

The electronic circuits of the watch can also be programmed such that prolonged pressure on the pushers cause the application of a succession of jumps in one direction or the other, or an acceleration in the application of these jumps.

When a jump back is made, at least the value of the stored measurement immediately before that which corresponds to the depth to be displayed after the jump is read in order to calculate a speed of variation of the recovery depth. In this case, the speed displayed by this means at the time of resuming the progress of the history is an instantaneous speed.

It is also possible to provide, in a general manner, and more particularly in the case where a jump is made forward in the course of the history, that at least the stored value which immediately follows the value from which the normal progress of the history is resumed is read and taken into account in the calculation of the speed of variation of the depth associated with the value of depth of recovery. Such a measurement makes it possible to smooth the display of the speed of variation of the depth in the historical mode.

The figure 3 represents a schematic diagram on which curves are plotted, on the one hand, of the depth as displayed during a dive (curve 100) and as reproduced in the historical mode (curve 200) and, d on the other hand, the rate of variation of the depth as displayed during a dive (curve 300) and as reproduced in the historical mode (curve 400).

Since the recording period is greater than the period of the measurements made by the sensor, it follows from these curves that the stored values give rise to levels of values in the history flow. It should be noted, however, that Historical mode is performed at accelerated speed, in principle, with respect to the course of the dive during which the measurements are recorded. Thus, the bearings visible on the curve are in practice not discernible during the analog display of history using the needles 16 and 17.

The foregoing description attempts to describe a particular embodiment by way of non-limiting illustration and the invention is not limited, for example, to the sequences of actions described for activating or deactivating the one or the other mode of operation, the measurement or recording periods specifically mentioned, the number of external control elements, the graduations as described and shown or the number of indicator hands used.

Of course, in practice, those skilled in the art can provide that the device is adapted to allow the recording of several series of data associated with periods of activity, such as diving, spaced apart in time from each other, without departing from the scope of the present invention. The latter is, in this case, not limited to the method used to navigate the different series of data stored in the device memory.

It is also possible to provide that the reading period of the values stored during the course of the historical mode differs from the measurement recording period during a dive without departing from the scope of the invention.

As mentioned above, the present invention is not limited to a diving watch. It is possible to apply the content of the present disclosure for the realization of an altimeter, a barometer or any other device comprising a sensor other than a pressure sensor, such as a temperature sensor.

Claims (15)

Portable electronic device (1) comprising a housing (2) containing a watch movement surmounted by a display (10, 12, 16, 17, 18), said watch movement comprising electronic circuits (21, 22) capable of producing signals schedules to control means (27) of said display, said electronic circuits being arranged to be selectively in one or more of a plurality of modes of operation, said plurality of modes of operation including a first mode , said time mode, wherein said display is provided to indicate the time, the electronic device (1) further comprising a sensor (23) provided for performing a measurement of a physical quantity and for renewing said measurement with a given frequency said plurality of modes of operation comprising a second mode, said acquisition mode, wherein the display is provided to provide a first indication representative of the a current value of said measurement, and a second indication representative of a variation in time of said measurement, the electronic device further comprising storage means (25, 26) provided for, in said acquisition mode, to record according to a given periodicity a succession of instantaneous values of said current value, characterized in that said plurality of modes of operation comprises a third mode, said historical mode, wherein said electronic circuits are provided for, on the basis of said succession of recorded values, displaying, in a predetermined time interval, two chronological sequences of values, a first of said sequences being directly representative of the values taken by said measurement in said acquisition mode, and the other of said sequences being calculated from said succession of values recorded and being representative of the variation in the time of said measurement. Device according to claim 1, characterized in that the display comprises graduations (10, 12) and two analog display members (16, 17) arranged opposite said graduations. Device according to claim 2, characterized in that said first indication representative of the current value of said measurement, and said second indication representative of a variation in time of said measurement are respectively indicated by said two analog display members (16, 17). Device according to claim 1, 2 or 3, characterized in that said storage means have a random access memory (25) and a stable memory (26), only a value representative of said given periodicity and said succession of values each corresponding to a instantaneous value of said current value being stored in said stable memory. Device according to one of the preceding claims, comprising an external control member (7, 8, 9), characterized in that said electronic circuits (20, 21) are arranged to interrupt the running of said historical mode in response to an action of a user on said external controller. Device according to claim 5, characterized in that said electronic circuits (20, 21) are arranged to resume the running of said historical mode in response to a new action of the user on said external control member (7, 8, 9) . Device according to any one of the preceding claims, comprising an external control member (7, 8, 9), characterized in that said electronic circuits (20, 21) are arranged to make a jump in the unfolding of said historical mode, in responding to an action of a user on said external controller, for controlling said display (16, 17) to change from displaying a first value associated with a first stored value Pi to displaying a second value associated with a second stored value Pj located chronologically before or after said first stored value Pi and spaced in time from the latter more than once the value of said given periodicity. Device according to claim 7, characterized in that the value representative of the variation in time of said physical quantity associated with said value Pj is calculated at least on the basis of the stored values Pj and Pj _-1 Device according to Claim 8, characterized in that the said sensor is a pressure sensor (23) making it possible to display the altitude and the speed of variation of the altitude or the depth and the speed of variation of the depth, and in what said electronic circuits (20, 21) are arranged to calculate, $V_i=\left(\frac{P_i-P_{i-1}}{T}+V_{i-1}\right)/2$

during a running of said historic mode without user intervention, the speed Vi of variation of the altitude or of the depth according to the formula: where Pi and Pi _-1 are the respective values of altitude or depth at times i and i-1, Vi-1 is the value of the rate of change of altitude or depth at the instant i-1 and T is the value of said given period. Device according to claim 9, characterized in that said electronic circuits (20, 21) are arranged to calculate the speed Vi of variation of the altitude or of the depth according to the alternative formula: $${\mathit{V}}_{\mathit{i}}=\frac{{\mathit{P}}_{\mathit{i}}-{\mathit{P}}_{\mathit{i}-1}}{\mathit{T}}$$

when the total duration of the measurements exceeds a predefined value. Device according to claim 8, characterized in that, in said second mode of operation, said value representative of the variation in time of said physical quantity associated with said value Pj is calculated at least from the variations between the stored values Pj and Pj _-1 , Pj _-1 and Pj _-2 , and Pj _-2 and Pj _-3 . A method of displaying a history for a portable electronic device (1) comprising a housing (2) containing a clockwork movement surmounted by graduations (10, 12), said clockwork movement comprising electronic circuits (20, 21) capable of generating time signals to motor means (27) controlling at least two analog display members (16, 17), said analog display members being arranged opposite said graduations (10, 12) to display the current time in a first mode of operation said time mode, the electronic device (1) further comprising a sensor (23) of a physical quantity, the method comprising the steps of: a) performing, in a first step, a periodic acquisition of the value of said physical quantity as a function of time, in a second mode of operation of said electronic device, b) storing at least a portion of the measured values, with a given period, in storage means (26), c) storing a value representative of said given period in said storage means,
characterized in that it further comprises, in a third mode of operation said historic mode, a subsequent step of d) controlling said motor means to perform a chronological display representative of the stored values of the physical quantity as a function of time, at least a first (17) of said analog display members indicating, opposite said graduations (10), the value of a variable directly related to said stored values, the second of said analog display members (16) being controlled to indicate, opposite said graduations (12), the value of a variable calculated from at least two of said stored values. Method according to claim 12, characterized in that the progress of step d) is interrupted in response to a first predefined action of a user. Method according to claim 13, characterized in that the progress of step d) is resumed in response to a second predefined action of a user. A method according to claim 12, characterized in that the representative display of the stored values of the physical quantity in step d) may have a chronological discontinuity with respect to said stored values in response to a third predefined action of a user.

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