KR20070030664A - Altimeter watch - Google Patents

Abstract

The present invention relates to a method in which the electronic watch automatically exits the altimeter mode, which method comprises: (a) entering the altimeter mode by activating the altimeter module of the watch, using the pressure sensor of the watch, Measuring (b) at least one first pressure value P1 used to calculate a first altitude value H1 and using the pressure sensor to calculate a second altitude value H2 (C) measuring at least one second pressure value (P2), and using the change detector of the altimeter module, the difference between the first pressure and the second pressure (P2-P1), or the first altitude (D) comparing the difference H2-H1 between the value and the second altitude value with a designated pressure change threshold S _VP or a designated altitude change threshold S _VH , and as a result of the comparison, a specified pressure change Threshold, or higher than the specified altitude change threshold , Out automatically exit from the altimeter mode is characterized in that it comprises a step (e) for stopping the display of altitude values by the analogue display means.

Description

Altitude Clock {ALTIMETER WATCH}

1 is a diagram illustrating the front of an altitude clock.

2 is a diagram for operating the visual mode and altitude mode states using the control components of the watch.

3 is a diagram illustrating an electronic circuit of the watch.

4 illustrates the steps of the first method for exiting the altimeter mode.

5A-5D illustrate a first example of exiting altimeter mode according to a second preferred method of exiting altimeter mode.

6A-6C illustrate a second example of exiting altimeter mode according to a second preferred method of exiting altimeter mode.

The present invention generally relates to an electronic clock equipped with an altimeter function. In detail, the present invention provides a watch comprising a pressure sensor for measuring external pressure, an altitude module for calculating an altitude value as a function of the measured pressure value, and an analog display means for displaying the calculated altitude value. It is about.

In the prior art, in particular, EP patent no. At 1 396 766 A1, an electronic analog display dive watch has been disclosed in which current time display hands are used to display diving-related data, in particular the diver's instantaneous depth. The watch is equipped with a pressure sensor for measuring external atmospheric pressure, and a depth gauge module for calculating the depth of the diver as a function of pressure measurement, and the depth calculated using one of the hands of the watch is displayed.

In the same way, it can be seen that the depth gauge module can be replaced with a module for displaying the calculated altitude by means of the analogue display means by calculating the altitude value based on the measured pressure.

However, this kind of altitude clock has the disadvantage that depends on which one is used to be displayed. During swimming, a person wearing a watch typically moves his arms regularly in and out of the water. Thus, when the altimeter mode is activated, the pressure value measured by the sensor will change significantly at every instant the medium changes between air and water. This type of swimming activity, where the swimmer's arm submerges up to several tens of centimeters into the water if the change in pressure observed when the user dives 10 centimeters into the water corresponds to a change in altitude of 100 meters in the air, This means that altitude indications can be changed by tens of meters. For analog display means, it is generally easier to read for a person wearing a watch, but in this case, when the first position corresponding to the actual altitude at the surface and the swimmer's arm are under water, The disadvantage is that there is an apparent altitude error that results in the movement of the indicator means (eg clock hands) between the second positions corresponding to errors indicating lower altitudes. For example, if a swimmer swims in a lake located at an altitude of 400 meters, and the swimmer's arm periodically moves to a depth of 40 cm below the surface of the lake, the analog altitude indicator is 400 meters (ie It will continue to move between the scale on the surface) and 0 m (ie the arm is below the surface of the lake). It is undesirable that the altimeter mode be operated in this manner. When the analog altitude display means moves significantly in altimeter mode, the user is not sure that his watch is operating properly, while jumping back and forth is excessive because the analog display means is controlled by a motor. It will result in power consumption, which is never desirable in portable machines.

One of the main objectives of the present invention is to overcome the aforementioned disadvantages by implementing a method for automatically exiting from the altitude mode. The invention also relates to an electronic altitude clock for implementing such a method.

Accordingly, according to a first aspect, the present invention relates to a method for automatically exiting an electronic clock equipped with an altimeter mode from the mode, which method follows the following steps.

 (A) entering the altimeter mode by activating the altimeter module of the watch;

(B) measuring at least one first pressure value P1 used to calculate a first altitude value H1 using the watch's pressure sensor

(C) measuring at least one second pressure value P2 used to calculate a second altitude value H2 using the pressure sensor

Using a change detector of the altimeter module to change the specified pressure change between the first pressure and the second pressure (P2-P1) or the difference between the first and second altitude values (H2-H1) (D) comparing with a threshold value S _VP , or a specified elevation change threshold value S _VH .

(E) automatically exiting the altimeter mode and discontinuing display of the altitude value by analogue display means when the result of the comparison is higher than the specified pressure change threshold or the specified altitude change threshold;

According to a preferred implementation of the method, the pressure value measurement and altitude value calculation of steps (b) and (c) are repeated at the specified sampling frequency, and step (d) comprises the following substeps.

Comparing the first calculated altitude value hn-4 with the last second calculated altitude value hn-1 and comparing the altitude value hn-1 with a specified altitude variation threshold S _VH . Step (d1)

Comparing the first calculated altitude value hn-4 with the last second calculated altitude value and comparing the last calculated altitude value hn with an equally designated altitude variation threshold (d2)

And step (e) automatically exits the altimeter mode when the two different results performed in steps (d1) and (d2) are greater than the specified altitude change threshold, resulting in an altitude value by the analog display means. The display is characterized in that the step of stopping.

It is possible for the pressure filter to be used so that the calculation of each altitude value is based on two or more previously measured pressure values n, n-1, n-2, to form an average pressure value p n.

According to a second aspect of the invention, the invention also relates to an electronic clock, which comprises an altimeter module for calculating an altitude value from a pressure sensor 14 and a pressure value measured by the pressure sensor in altimeter mode. (15) and display means (3, 4) for displaying the calculated altitude value, wherein the altimeter module includes a fluctuation detector comprising two pressure values, or a subtractor for receiving each altitude value; 20, a comparator for performing a comparison between the results provided at the output of the interpolator and a pressure change threshold, or each altitude change threshold, and a difference value between the two pressure values, or each altitude value; When higher than the pressure fluctuation threshold, or altitude change threshold, the altimeter mode is automatically exited and the altitude value by the analog display means To end the display, and includes a mode selecting means (21) controlled by the output of the fluctuation detector.

Preferably, the altimeter module further includes a pressure filter or an altitude filter, and supplies an average pressure value or an average altitude value to the fluctuation detector, respectively.

The following description is provided by way of example in its entirety. 1 illustrates the front of an altitude watch 1 used in an altimeter mode according to an embodiment of the invention. As shown in FIG. 1, the dial 2 of the watch points to the hour hand 3 and minute hand for providing visual indications by pointing to the internal scale 5 of the dial in analog display means, for example in the display mode of the watch. It includes (4). The watch comprises a second scale 6 arranged on the bezel of the watch. This scale used in altimeter mode includes altitude indications of 0 m to 9990 m. The display is preferably arranged in the following manner. When the altitude to be displayed is less than 1000 m, the two hands are superimposed and positioned towards the scale corresponding to the altitude. When the altitude to be displayed is 1000 m or more, in this example, when the altitude is 2550 m, one of the clock hands, in this example, the hour hand 3 is positioned toward the 2000 m numeric scale, and the remaining clock hands, in this example the minute hand (4). ) Is located toward the remainder of the altitude, i.e. 550 m. This different display technique, which depends on whether the altitude is less than 1000 m or higher than 1000 m, is very clear and easy for the user to read, even if the altitude is displayed over a wide altitude range (0 to 9990). Provide an advantage. Are you facing sea level (100, 200, 300, ...) at risk of confusion between altitudes of 100, 200, 300 and indications of altitudes of 1100, 2200, 3300? Or if it is in contact with acid levels 1100, 2200, 3300, ..., the risk is lessened. Of course, as in the case of displaying the current time, although it is desired that the indication provided by the hour hand is larger than the indication provided by the minute hand, the roles of the two hands can be interchanged.

The clock further comprises a control component 7 for switching between the visual mode and the altimeter mode. The control component 7 can be implemented in various ways. An example could be a stem-crown, a push button, a touch crystal, or by sensing an impact on the case using an accelerometer.

2 is a diagram of the operating states of the visual and altitude modes using the control components of the watch. In order to simplify the description of FIG. 2, the control component is a stem-crown. However, other combinations of control components can also be used.

The current state E1, or initial state, is a time mode in which the watch provides a visual indication to the user using a clock hand, wherein the position of the stem-crown is in the first non-pulled out position. Unpositioned position) T1. From this viewing mode, it is possible, in a conventional manner, to provide a second pulled out position T2 of the stem-crown, in which the second pull-out position T2 is operated. Rotating the stem-crown allows the user to adjust the visual indication. This time setting mode of the clock corresponds to state E2 on the figure. By re-positioning the stem-crown to the non-pulled out position T1, the watch returns to the initial state E1, or visual mode. A short pressure is applied (PC) on the stem-crown from the original state E1, ie from the visual mode, so that the clock provides altitude indication for a specified short time period, after which the time period expires or the stem- When another pressure is applied to the crown (5 seconds, or PC), the intermittent altitude mode of the watch which returns to state E1 is activated. For example, short application of pressure means pressure for less than 2 seconds, and the short time period before returning to the visual mode may be fixed at 5 seconds. In a watch in the original state E1 (visual mode), according to the long application of pressure on the stem-crown (PL), the watch's continuous altimeter mode (E4) is activated, which is much longer than the intermittent altimeter mode. The watch provides altitude indication for a specified time period. After this designated long time period has expired, or after another long pressure application to the stem- crown has been made (12 hours, or PL), the watch returns to the time mode (state E1). For example, a long application of pressure includes 2 to 5 seconds, and the long time period before returning to the visual mode is 12 hours. By applying a short pressure on the stem-crown in state E4 (PC), for a short period of time, for example 5 seconds, the watch provides a visual indication until another short pressure is applied. The intermittent visual mode (state E5) may be activated until returning to the continuous altimeter mode (state E4). From intermittent altimeter mode (state E3) and continuous altimeter mode (state E4), the stem-crown position can be entered into the altimeter calibration mode (state E6) by setting the pulled out position T2. In the altimeter measurement mode, it is possible to adjust the displayed altitude by rotating the stem-crown. The application of very long pressure (PTL) to the stem-crown in the visual mode (state E1) sets the position of the stem-crown to the pull-out position T2 and resets the clock hand by rotating the stem-crown. Means the ingress to the clock hand reset mode (state E7). By repositioning the stem-crown position to the non-pull out position T1, a return to the viewing mode is achieved.

3 is a block diagram illustrating an example of an electronic circuit of an altitude clock according to one embodiment of the present invention. In the visual mode, the time base 11 of the clock controls the forward and backward movement of the motor 12 which operates the clock hands 13, 14 displaying time-related information. By activating the control component 17, it is possible to switch the clock from time mode to altimeter mode and vice versa. As mentioned above, any kind of control component may be used. Mode selection means 21 are provided for selectively activating / deactivating (ALTI_SEL) the altimeter mode and the visual mode. While this selection means 21 is presented here in the form of a logic gate located in the upstream direction of the two switches and one inverter, any other suitable electro-mechanical device may be provided. The altimeter module 15 is activated while going through the altimeter mode. The altimeter module 15 calculates an altitude value based on a pressure sensor 16 measuring external atmospheric pressure, a frequency sampling unit 18 whose pressure measurement is controlled by a time base of the clock, and the measured pressure. A pressure-altitude converter 19 and a fluctuation detector 20 that allows the watch to exit the altimeter mode when the pressure fluctuation (path A) or altitude fluctuation (path B) exceeds a specified fluctuation threshold. do. For example, the fluctuation detector 20 receives two pressure values (path A), or uses a pressure fluctuation threshold (path A), or an altitude fluctuation threshold (path B) to provide two altitudes provided by the comparator. It may be implemented in the form of a subtractor that receives one of the values (path B). More generally, the variation detector 20 may be implemented in the form of a logic circuit programmed in a microcontroller, or a logic equation, wherein a function of development of one function for pressure measurements made between two specified time intervals A comparison of the specified variation threshold equal to the result of the function is made. When the result of such a comparison performed by the variation detector 20 requires automatic exit from the altimeter mode, the variation detector 20 sends an automatic stop signal AUTO_OFF to the input of the mode selection means 21. . The ALTI_SEL signal is then deactivated, which allows the clock to automatically exit the altimeter mode, after which the analog display means switches to the visual mode.

The operation of the altimeter mode will be described in detail in connection with the first method of automatically exiting the altimeter mode with reference to FIG. 4, and the second method of automatically exiting the altimeter mode from FIGS. 5A-5D and FIGS. It will be described with reference to 6c.

4 illustrates a first method for automatically exiting from altimeter mode. In this case, the sampling frequency is set to be 1 kHz. In other words, one pressure measurement is made per second. In order for the pressure-altitude converter to calculate the altitude value, the following formula can be used.

H = 153.85 x T ₀ x [1- (P / P ₀ ) ^0.190255 ] ············ (1)

At this time, T0 = 228.15K = 15 ° C, P represents the atmospheric pressure of the barometer, and P0 = 1013.25 mbar at sea level. The above equation is defined at a temperature change rate of -6.5 ° C / 1000m (ie, a temperature drop of 6.5 ° C with an elevation of 1000m).

When the control component of the watch is activated, the component returns to altimeter mode (step a)). The altimeter module 15 is activated by entering altimeter mode. The measurement frequency sampling unit 18 clocked by the time base 11 of the clock controls the pressure sensor 16 so that pressure measurement at the desired frequency (1 Hz in this example) can be made. In step b), a first pressure measurement is made and the measured pressure value P1 is provided to a pressure-altitude converter 19 which calculates an altitude value H1 corresponding to the measured pressure value. The pressure value H1 thus calculated can then be displayed by the analog display means 13, 14 for the altitude value. In step c), a second pressure measurement is made and the pressure value P2 thus measured is provided to the pressure-altitude converter 19 which calculates the second altitude value H2.

According to the alternative represented by path A in FIG. 3, two measured pressure values P1 and P2 are fed to the fluctuation detector 20, which fluctuates the difference P2-P1 between the two values. S _VP ), if (P2-P1≥S _VP ), it may be considered that the altimeter is not in use in a real environment, after which the watch automatically exits from the altimeter mode (step e)). According to an alternative indicated by path B in FIG. 3, two calculated altitude values H1 and H2 are supplied to the fluctuation detector 20, which fluctuates the altitude difference H1-H2 to the specified altitude fluctuation threshold S. _VH ), when (H1-H2 ≧ S _VH ), the watch automatically exits from altimeter mode (step e)). In both alternatives, it is desirable that a variation threshold (S _VP , S _VH ) higher than the threshold for free-falling persons is chosen. Therefore, on path B, it is desirable to select S _VH = 100 m to sample a frequency of 1 kHz. That is, the threshold corresponding to a drop of 100 meters per second, which is higher than the speed of the free-falling person. If the pressure fluctuation P2-P1, or the altitude fluctuation (H1-H2) is less than the pressure fluctuation threshold S _VP , or the altitude change threshold S _VH , respectively, the calculated altitude H2 is displayed and another pressure measurement P3 is made. , Another altitude H3 value corresponding thereto is calculated, and then a comparison step d) is performed using the two measured pressure values P2 and P3 and the calculated two altitude values H2 and H3. Alternatively, it may be possible to compare the absolute value of the pressure fluctuation (path A), or the absolute value of the altitude fluctuation (path B) with the pressure, or respective altitude fluctuation threshold, respectively.

As a variant of this first method, it is possible to compare discontinuous pressure values or altitude values. It is desirable to compare two altitude values separated by three seconds with the altitude variation threshold S _VH at 300 m.

According to another variant, it is preferred to use a "pressure filter", in order to find the average pressure value, the pressure sensor comprises a circulation buffer of three recently measured pressure values. Or a circular buffer of these three recently measured altitude values may be used.

5A-5D illustrate a second preferred method of automatically exiting from the altitude mode, to exit to a maximum value of 3 seconds in case of an altitude variation that is considered excessive or not substantial. FIG. 5A shows the pressure measurement sample and the corresponding altitude calculated by the pressure altitude converter. In this example, the sampling frequency is chosen to be equal to 1 kHz. According to this second method, in that the pressure sensor includes a circulation buffer containing the three most recent pressure measurements (n, n-1, n-2), a pressure sensor is given an average pressure value given by Based on the transmission to the pressure-altitude converter, a "pressure filter" is preferably used.

Pn = [n + (n-1) + (n-2)] / 3 ·············· (2)

Based on formula (1), the pressure-altitude converter calculates a filtered altitude that depends on the average value of the last three pressure measurements according to formula (2). As will be described in detail herein, the use of a pressure filter provides the advantage that the first measured pressure value does not automatically exit the altimeter mode as soon as the first threshold is exceeded. Alternatively, the use of the "altitude threshold" may be considered using the displayed altitude computed from formula (1) by the last three altitudes.

FIG. 5B illustrates a first “non-trigger” measurement sample, ie, for the sample, the filtered altitude value does not automatically trigger the clock to exit altimeter mode. . 5b corresponds to five filtered altitudes (hn, hn-1, hn-2, hn-3, hn-4) calculated based on previous pressure measurements according to formulas (1) and (2), Five pressure samples (n, n-1, n-2, n-3, n-4) are plotted.

The purpose of the variation detector 20 is to check whether the altimeter mode should remain active as a function of detected altitude variation or pressure variation. In the case of too much variation during a given time period, the detector sends a signal to automatically exit the altimeter mode.

To do this, it is desirable that two conditions are checked for each sample, that is, every second in this example. Advantages are provided by using dual conditions. This is because, for example, when the user washes his wrist, the sensor may be briefly exposed to the sprayed water, or when the user controls the motorcycle or moves his wrist out of the window of a fast moving car. In addition, the watch is prevented from suddenly exiting the altitude mode when the sensor is suddenly exposed to a huge air flow.

The first condition represented by the open rectangle c1 consists of checking whether the last altitude value calculated is lower than the altitude value specified from the altitude value hn-4, calculated four seconds earlier than the subtracted value. have. Therefore, the first condition may be expressed as follows.

hn <(hn-4-"elevation criterion")

The second condition represented by the open rectangle c2 consists of checking whether the last altitude value hn-1 is lower than the specified altitude value subtracted from the altitude value calculated three seconds earlier. The second condition may be expressed as follows.

Hn-1 <(hn-4-"altitude criterion")

If the user wants to exit the altimeter mode up to three seconds after excessive altitude fluctuations are detected by this second method, they are more than the possible altitude fluctuations during the three seconds of free fall (e.g. during parachute jump before unfolding the parachute). The altitude criterion is set to be large. This criterion is preferably set to be 300 m. Therefore, the watch must have an altitude fluctuation of 300m (condition c2) for at least 3 seconds to automatically exit altitude mode. Also, two conditions c1) and c2) compare the last calculated altitude value (hn) and the last second calculated altitude value (hn-1) with the previously calculated altitude value (hn-4), respectively. This prevents the watch from suddenly exiting the altimeter mode while effectively detecting any inappropriate use that requires the watch to exit the altimeter mode.

As shown in FIG. 5B, a case may occur in which neither of the two conditions (c1) and (c2) is fulfilled. The altitude value hn-4 is located outside of the two rectangles c1 and c2, and the defined altitude criteria do not exceed this.

5C illustrates the case of an intermediate sample in which only the first condition c1 is performed. In the illustrated example, since the last altitude value hn corresponding to the last pressure sample n taken is lower than the previous altitude value hn-1, the user of the watch is in the water. However, because of the pressure filter, the value obtained does not satisfy the second condition c2. Of course, as is clearly shown using the squares c1 and c2, the altitude value hn-4 is inside the square c1, and thus the first condition is performed. However, this same altitude value hn-4 is outside the rectangle c2, and thus the second condition is not performed. As a result, the watch remains in altitude mode.

5D illustrates a sample where both conditions are performed, causing the watch to exit altitude mode. In FIG. 5D, the user is still in water, so a second pressure value is measured which corresponds to an unrealistic altitude value. Since the pressure filter makes the last three pressure measurements, the filtering effect is reduced by using two higher pressure values of the three. Once again, rectangles (c1) and (c2) indicate that two conditions are to be checked. As shown, the value hn-4 is inside the rectangle c2, not inside the rectangle c1. Thus both conditions are performed. That is, the altimeter detects an altitude fluctuation higher than the free fall altitude fluctuation. In particular, this example detects altitude fluctuations of more than 300m in 3 seconds. As a result, the fluctuation detector may transmit an altitude mode escape signal to prevent the watch hands from displaying unreal fluctuations that may erroneously affect the user. Thus, three seconds pass between the first unrealistic and excessive pressure measurement and the escape from the altitude mode.

With reference to FIGS. 6A-6C, in accordance with a second automatic escape method, a predicted example of escape due to sudden pressure, or altitude fluctuation is illustrated. 6A plots a high graph as a function of pressure sample. The region formed by the dotted line represents the moment when the pressure measurement is changed suddenly. For example, if a user submerges into water, or if the measurement of the preceding change is made at the surface and the next measurement is made in deep water, this change occurs.

6B depicts the first sample after a sudden change in pressure. As mentioned above, the same two conditions (c1) and (c2) are used. Since the altitude value hn-4 is located inside the rectangle c1, the first condition c1 is performed. Since the last calculated altitude value hn has not yet been taken into account, the second condition c2 is not explicitly performed.

6C analyzes a second sample after a sudden pressure change. The first condition is still performed and a second unreal altitude value is calculated. In addition, the second condition c2 is also performed. The altitude value used as a reference is a value corresponding to the preceding sample. That is, the new value hn-1 and the preceding altitude value hn of FIG. 6B. Since both conditions (c1) and (c2) are performed, the fluctuation detector sends an automatic altitude mode escape signal two seconds after the unrealistic altitude value has been calculated.

It is apparent that various modifications and improvements can be applied to the method of exiting from the altitude mode and to the watch for implementing the method, within the spirit and scope of the present invention. In particular, as analogue display means, various alternatives can be used. For example, instead of the use of a clock hand, a graduation disk, or a mechanical counter can be used. For pressure filters, it is conceivable that an average of smoothing only two pressure values is defined, which has the advantage of having a more reactive altitude value. Or, on the contrary, an average of smoothing the four pressure values is defined, which has the effect of making the altitude fluctuation less abrupt and reducing the sudden movement of the clock hand during the apparent fluctuation of the measured pressure. However, this smoothed average is more likely to prevent the computed altitude value from becoming completely smooth, which can prevent the detection of improper motion by the user in altimeter mode and thus prevent it from effectively exiting the mode. It is not based on values.

When the analog altitude display means moves significantly in altimeter mode, the user is not sure that his watch is operating properly, while jumping back and forth is excessive because the analog display means is controlled by a motor. It will result in power consumption, which is never desirable in portable machines. Therefore, one of the main objectives of the present invention is to overcome the aforementioned disadvantages by implementing a method for automatically exiting from the altitude mode. The invention also relates to an electronic altitude clock for implementing such a method.

Claims (11)

A method for automatically exiting an electronic clock equipped with an altimeter mode from the mode, the method comprising:  (A) entering the altimeter mode by activating the altimeter module of the watch; (B) measuring at least one first pressure value P1 used to calculate a first altitude value H1 using the watch's pressure sensor, (C) measuring at least one second pressure value P2 used to calculate a second altitude value H2 using the pressure sensor, Using a change detector of an altimeter module, the difference between the first pressure and the second pressure (P2-P1), or the difference between the first and second altitude values (H2-H1) is determined by a specified pressure change threshold. (S _VP ), or comparing with the specified altitude change threshold (S _VH ) (d), (E) automatically exiting the altimeter mode and stopping the display of the altitude value by the analogue display means when the comparison results, when higher than the specified pressure change threshold or the specified altitude change threshold ,; And an electronic clock equipped with an altimeter mode automatically exits from the mode. 2. The method of claim 1, wherein the designation change threshold (SVP) is higher than the altitude fluctuation for the free-falling person. 3. An electronic clock equipped with an altimeter mode according to claim 2, wherein the two altitude values are considered over a period of three seconds and the altitude change threshold S _VH is 300 m. How to get out. The pressure filter according to any one of claims 1 to 3, wherein the pressure filter is used in steps (b) and (c), wherein steps (b) and (c) (B) measuring at least two first pressure values forming a first average pressure value P1moy, which is used to calculate a first altitude value H1, using a pressure sensor of a watch; Measuring (c) using the pressure sensor one or more second pressure values P2 forming a second average pressure value P2moy used to calculate a second altitude value H2 And an electronic clock equipped with an altimeter mode automatically exits from the mode. The method of claim 1, wherein the pressure value measurement and altitude value calculation of steps (b) and (c) are repeated at a specified sampling frequency, and step (d) First comparing the calculated altitude value hn-4 with the second and second calculated altitude values hn-1, and comparing the altitude value hn-1 with a specified altitude variation threshold S _VH . (d1),  Comparing the first calculated altitude value hn-4 with the second and second altitude values calculated, and comparing the last calculated altitude value hn with an equally designated altitude variation threshold (d2). Wherein step (e) comprises When the two different results performed in steps (d1) and (d2) are greater than the specified altitude change threshold, the altimeter mode is automatically exited and the display of the altitude value by the analog display means is stopped. Characterized in that an electronic clock equipped with an altimeter mode automatically exits the mode. 6. The method of claim 5, wherein the first calculated altitude value used in steps d1 and d2 is a fourth altitude value hn-4 preceding the last calculated altitude value hn, Wherein the variation threshold can be selected to be 300 meters, wherein the electronic clock equipped with an altimeter mode automatically exits the mode. 7. The pressure according to claim 5 or 6, wherein the calculation of each altitude value is based on at least two previously measured pressure values n, n-1, n-2 to form an average pressure value p n. A method for automatically leaving an electronic clock equipped with an altimeter mode, characterized in that a filter is used. 4. The method of any one of claims 1 to 3, wherein during step (e), the step of stopping the display of the altitude value comprises switching the analogue display means into a time mode. Characterized in that an electronic clock equipped with an altimeter mode automatically exits the mode. In the electronic clock 1, the electronic clock is Pressure sensor (14), In altimeter mode, altimeter module 15 for calculating the altitude value from the pressure value measured by the pressure sensor, Display means (3, 4) for displaying the calculated altitude value Includes, wherein the altimeter module A fluctuation detector 20 comprising a subtractor receiving two pressure values, or respective altitude values, A comparator for performing a comparison between the results provided at the output of the interpolator and a pressure change threshold, or each altitude change threshold, When the difference between the two pressure values, or the respective altitude values, is higher than the pressure fluctuation threshold, or the altitude change threshold, the altimeter mode is automatically exited to stop displaying the altitude value by the analog display means. Mode selection means 21 controlled by the output of the variation detector Electronic clock comprising a. 10. The electronic clock of claim 9, wherein the altitude module further comprises a pressure filter for supplying an average pressure value to the variation detector. 10. The electronic clock of claim 9, wherein the altitude module further comprises an altitude filter for supplying an average altitude value to the variation detector.

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