Patent Grant
7593292
This application claims priority from European Patent Application No. 05106032.5, filed Jul. 1, 2005, the entire disclosure of which is incorporated herein by reference.
The present invention concerns, generally, a multi-function electronic watch powered by a non-rechargeable primary energy source including analogue display means operating in synchronism with a value representative of a time-related item of information contained in a volatile time counter whose value is calculated by means of a time base in a first operating mode of the watch, called the “time mode”, and operating asynchronously with said value in a second operating mode of the watch, called the “non-time related mode”. The invention concerns more specifically a simplified synchronisation method between the analogue display means and the value of the counter when the primary energy source is replaced.
In the prior art, multi-function electronic watches are known that include a time base for calculating a value representative of a time-related item of information, namely the current time, a volatile time counter which stores the calculated value representative of the current time and the position of the analogue display means, namely the hands, operating in synchronism with this calculated value in a first operating mode, called the “time mode”, and operating in an asynchronous manner with the calculated value in a second “non-time-related” mode, like for example a chronograph mode, a compass mode or even a weather mode.
For obvious reasons of cost and available space in such multi-function watches, it is preferable to power the watch by means of a primary energy source. However, at the end of the life of such a primary energy source, on the one hand, the hands are stopped when the energy provided by the source is perceived to be insufficient to move them, and, on the other hand, the value of the counter is corrupted when the source is insufficient to power the time counter and zero reset when the primary energy source is replaced. Thus, after the primary energy source has been replaced, the value contained in the time counter no longer corresponds to the value corresponding to the position in which the hands were or have been stopped. In cases where the user resets the time after replacing the primary energy source, as the hands operate in synchronism with the time counter value, the shift between the position of the hands and the value contained in the time counter remains. Although this shift in no way prevents the watch from operating normally in its time mode, this raises a problem when the user wishes to use the non-time related mode of the watch. Indeed, in the non-time related mode, the watch is supposed to place the hands in a reference position which it determines as a function of the value contained in the time counter, which is supposed to match the actual position of the hands. Thus, the hands are brought into incorrect positions in the non-time related mode, which causes the user to think that the watch is defective which is evidently undesirable.
One example of this malfunction is detailed in relation to
a shows, in time mode, dial 2 of the watch on which hands 4 and 6 indicate the current time, namely 10 minutes past 10 o'clock, in synchronism with the value contained in the time counter 8 of the watch.
b shows the same watch five minutes later, in non-time related mode, the latter being activated by the user. In this non-time related mode, hands 4 and 6 indicate a predetermined reference value, i.e. here both hands point towards the first indicator corresponding to 1 o'clock or 5 minutes, an additional indicator 10 being able to be arranged opposite on the bezel (not shown), or even on the dial or the crystal. Thus, the user knows that he is in the non-time related mode corresponding to indicator 10, the hands pointing in that direction. The correct positioning of the hands can be achieved simply by moving the hands independently of each other by means of their respective motor, since the electronic circuits of the watch know the start position of the hands defined by the value in the time counter, both being synchronous and the end position of the hands, the latter being predetermined for the non-time related mode selected. During operation in the non-time related mode, the value of the counter continues to be incremented by the time base, with the hands no longer being in synchronism with said value.
In
In
e shows either the state of the watch at the end of life of the energy source, or just after the energy source has been replaced. In the first case, the time counter is not longer being powered and the value that it contains is corrupted (reset to zero), the hands still indicating 20 minutes past 10 o'clock. The user is then aware that he has to change the energy source when he sees the hands have stopped, which brings us to the second case following the replacement of the energy source. In the second case, the counter value is reset to zero, or any other constant pre-set value, the powering of the counter having been interrupted for a relatively long time period, following replacement of the energy source. In the example shown, as the replacement has just occurred, the hands still indicate 20 minutes past 10 o'clock. It will thus be noted that there is a shift between the value contained in the time counter and the value corresponding to the real position of the hands.
Following the replacement of the energy source, as is shown in
g shows the position of the hands on the dial in the case presented in
In the first case (
In the second case (
In order to avoid this shift between the real position of the hands and the value representative of this position in a counter, certain solutions of the prior art provide for the use of a non-volatile memory for storing the position of the hands. Thus, even in the event of a prolonged interruption to the power supply, due for example to replacement of the watch battery, the value corresponding to the position of the hands is maintained and thus actually corresponds to the real position of the hands. However, this solution is not desirable for evident reasons of manufacturing costs, and available space in the printed circuit of the watch.
It is one of the main objects of the present invention to overcome the aforementioned drawbacks by implementing a synchronisation method between the analogue display means of the watch and the corresponding value stored in a volatile time counter for keeping the two matching in particular when the primary energy source of the watch is replaced.
Thus, within the scope of the present invention, there is provided a synchronisation method including the following steps:
Advantageous implementations of the method are described in the dependent claims 2 to 6.
According to another aspect, the present invention also concerns a multi-function electronic watch capable of implementing the aforementioned synchronisation method. This watch includes:
Other features and advantages of the present invention will appear more clearly upon reading the following detailed description of embodiments of the invention given solely by way of non-limiting example and illustrated by the annexed drawings, in which:
a to 1h show the evolution of the analogue display means and the time counter value of a multi-function electronic watch according to the prior art, in particular, when the battery is being replaced;
a to 3g show the evolution of the analogue display means and the time counter value of a multi-function electronic watch according to the invention, in particular, when the battery is being replaced;
The following description is provided solely by way of example, in particular,
For each motor 12 a time base 14 defines the step for advancing the hand associated with said motor. The time base generally used is formed, in particular, of a quartz oscillator and various frequency divider stages of the oscillator for driving each motor with the desired step. Drive means 16 for the motor or motors 12 are provided for this purpose.
The motor or motors 12 are powered by a non-rechargeable primary power source 18. A voltage comparator 20 is arranged at the output of power source 18. This comparator 20 receives the supply voltage Valim at a first input and a reference voltage Vre at a second input for comparing the supply voltage Valim to said reference voltage Vref. This reference voltage Vref is chosen such that if the supply voltage is higher than or equal to the reference voltage (Valim≧Vref), then the electronic circuits of the watch and the analogue display operate properly. Conversely, if the supply voltage is lower than the reference voltage (Valim<Vref), then the electronic circuits of the watch and especially the working of the hands are no longer guaranteed to operate properly. The result of the comparison is transmitted to stopping means 22 which, in the latter case where the supply voltage is insufficient to allow the watch to operate properly, cause the drive means of motor 16 to stop then to position hands 4 and 6 in a reference position so as to warn the user that the power source 18 is insufficient and that it therefore needs to be replaced. The reference position in which the hands are placed is preferably 12 o'clock.
A time-keeper circuit includes in particular a volatile time counter 8 which counts the time according to the pulses received by time base 14. In the time mode of the watch, the time value contained in counter 8 corresponds to an indication of the position of the hands, the latter then operating in synchronism with that value.
The watch, within the scope of the present invention, is a multi-function watch including at least one non-time related mode in addition to the time mode. In the non-time related mode, hands 4 and 6 provide a non-time related information item which is no longer in synchronism with the time value contained in counter 8. The watch includes means 26 for selecting this non-time related mode, which can be implemented for example in the form of a control member such as a push button. However, it should be noted that other types of selection means could be implemented, like for example a touch type glass, or automatic trigger as a function of a measurement made by a sensor of the watch. Following activation of selection means 26 of the watch, the latter switches from the time mode to a non-time related mode or vice versa depending upon the mode in which it was previously. In the case of passage from time mode to non-time related mode, the electronic part managing the non-time related application or applications is activated. Depending upon the non-time related mode selected by the user, the application control means 28 send a signal 32 to difference calculating means 30, corresponding to a reference value in which the hands have to be placed to indicate to the user that the desired mode has been selected. Thus, difference calculating means 30 receive, on the one hand, a reference value (Vpos) originating from the non-time related application control means 28, and on the other hand the time value (Vtps) contained in time counter 8. The result of the difference calculated by difference calculating means 30 enables a control signal 34 to be sent to the motor drive means 16 to move the hands from their current position to the reference position indicating the selected non-time related mode. Conversely, in the case of passage from a non-time related mode to time mode, difference calculating means 30 provides a control signal 34 to the hand drive means to move the hands from a reference position indicating the previously selected non-time related mode to a position corresponding to time information matching the time value contained in counter 8.
It should be noted that if the watch includes several non-time related modes, it is possible for the user to select one non-time related mode while the watch is in another non-time related mode. In such case, difference calculating means 30 receives two signals corresponding on the one hand to the reference position of the current non-time related mode (Vpos1), and on the other hand, to the reference position of the newly selected non-time related mode (Vpos2). The results of the difference (Vdif) thus enables passage directly from one reference position of the two non-time related applications to the other.
As was seen previously, the hands are automatically placed in a predetermined reference position when the supply voltage supplied by power source 18 is insufficient for the watch to operate properly. Thus, the user is warned of the need to replace the power source. As time counter 8 is of the volatile type, removal of the power source resets the time value that it contains to a predetermined reference value, for example to zero. After replacement of power source 18, the watch again operates correctly and the time value (here 0) contained in counter 8 actually matches the actual position of the hands which have been placed in the 12 o'clock reference position. If the predetermined reference position is offset in relation to 12 o'clock, the electronic circuits of the watch, which know of this shift, can adequately increment the time value of the counter such that the time value is representative of the actual position of the hands in time mode upon reset resulting from the replacement of the power source. When the actual position of the hands, i.e. the predetermined reference position in which they have been placed, does not match the current time, following replacement of the power source, which occurs in most cases, the user can then reset the time, for example by means of a conventional mechanism activated by a winding crown 36. In this time-reset mode, it is important for hands 4 and 6 to operate in synchronism with the time value of counter 8. For this purpose the time reset mechanism transmits a hand movement signal 38 to time counter 8, which can then update the time value so that this value is always representative of the real position of the hands in the time mode.
a to 3g show an example implementation of the synchronisation method according to the present invention.
a shows, in time mode, watch dial 2 on which hands 4 and 6 are indicating the current time, namely 10 minutes past 10, in synchronism with the value contained in time counter 8 of the watch.
b shows the same watch five minutes later, following activation of control member 26 by the user to select a non-time related mode of the watch. In this non-time related mode, hands 4 and 6 indicate a predetermined reference value, i.e. here both hands are pointing towards the first indicator of the dial corresponding to 1 o'clock or 5 minutes, an additional indicator 10 being able to be arranged facing the bezel (not shown) or even on the dial or the crystal. Thus, the user knows that the watch is in the non-time related mode corresponding to indicator 10, since the hands are pointing in that direction. The correct position of the hands can be achieved simply by moving the hands independently of each other by means of their respective motor, since the electronic circuit of the watch knows the start position of the hands defined by the value in the time counter, both being synchronous and the end position of the hands, the latter being predetermined for the selected non-time related mode. During operation in non-time related mode, the value of the counter continues to be incremented by the time base, with the hands no longer being in synchronism with said value.
In
In
e shows the watch following replacement of the power source. As the counter is a volatile memory, the value that it contains has been reset to zero during the prolonged power interruption due to replacement of the power supply. Thus, the counter value is again representative of the position of the hands in time mode. It will be noted that if the predetermined reference position is chosen to be offset in relation to 12 o'clock, this is not inconvenient provided the shift between the counter value and the real position of the hands is defined and thus known to the electronic circuit of the watch, and can therefore be corrected during the initialisation carried out following replacement of the power source.
f shows the watch following replacement of the power source and after the time has been reset by the user. In order to reset the time, the user activates winding crown 36 so as to reset the time of his watch, here 3:30. In this time reset mode, the time value contained in time counter 8 is altered in synchronism with the movement of the hands, and this value therefore also corresponds to 3 hours and 30 minutes in this example.
g shows the watch five minutes later, the time value of the counter is thus now 3 hours 35 minutes. Following activation of control member 26 by the user to select a non-time related mode of the watch, hands 4 and 6 have moved so as to indicate the predetermined reference value, in which both hands point to the first indicator corresponding to 1 o'clock, opposite additional indicator 10. The movement of hands 4 and 6 from the position that they occupied in time mode, i.e. 3:35 and this selected non-time mode reference position, is calculated by the difference calculating means of the watch. Since the counter value is still representative of the actual position of the hands in time mode, the latter have actually moved into the reference position of the selected non-time related mode, as shown, unlike the “fantasy” indications obtained with a solution of the prior art (see in particular
The invention thus concerns a method of synchronisation between analogue display means 4, 6 and the volatile time counter 8 during replacement of primary power means 18, which includes the following steps: (i) calculating a value representative (Vtps) of a time information item by means of the time base (14) of the watch; (ii) storing the value in the volatile time counter; (iii) updating the value in the volatile time counter periodically as a function of the supply frequency of a time information item by the time base; (iv) synchronized display of the value representative of a time information item by the analogue display means in a first operating mode of the watch; (v) non-synchronized display of a value not representative of a time information item by the analogue display means in a second operating mode of the watch; (vi) detecting the end of life of the primary power means powering the watch; (vii) setting the analogue display means in a predetermined reference position following detection of the end of life of the primary powering means; (viii) setting the value of the time counter to a predetermined reference value when the primary powering means are removed; (ix) automatic synchronisation between the analogue display means and the value of the time counter when the primary powering means are replaced.
Thus, according to the preferred implementation of the previously described synchronisation method, for which the watch includes a protected volatile memory zone including at least one fixed data zone (81, 83) and one variable data zone (82), the method further comprising the following steps: (x) storing the value (Vtps) representative of an item of time information in the variable data zone (82); (xi) detecting a zero reset of the electronic circuit of the watch; (xii) subsequently checking whether at least one part of the data (Vp1, Vp2) of the fixed data zone (81, 83) has been altered; (xiii) if there is no alteration to the fixed data zone, validating the value representative of an item of time information as being correct.
It will be noted that the protected volatile memory zone preferably includes two predefined fixed data zones (81, 83) arranged on either side of the variable data zone (82). Moreover, it will also be noted that the time counter preferably corresponds to the protected volatile memory zone. In such case, steps (ii) and (x) are one and the same. Alternatively, the protected volatile memory zone could be distinct from the time counter and in such case the step of storing the value representative of an item of time information in the protected volatile memory zone is carried out at a lower frequency than the frequency for updating the value in the time counter.
It will be understood that various alterations and/or improvements obvious to those skilled in the art can be made to the synchronisation method according to the invention described above without departing from the scope of the invention defined by the annexed claims. In particular, one could envisage using a rechargeable power source instead of the primary power source. In such case, the step of detecting the end of life of the power source is replaced by a step of detecting insufficient power, the step of setting the time counter value to a predetermined reference value is carried out after detection of insufficient power and the automatic synchronisation step between the analogue display means and the time counter value is carried out after the rechargeable power source has been recharged to a predetermined voltage threshold higher than the threshold defined for detecting insufficient power.
| Number | Date | Country | Kind |
|---|---|---|---|
| 05106032 | Jul 2005 | EP | regional |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5671192 | Schaffel | Sep 1997 | A |
| 6144622 | Berney | Nov 2000 | A |
| Number | Date | Country |
|---|---|---|
| 195 43 590 | Jan 1997 | DE |
| 2 671 646 | Jul 1992 | FR |
| Number | Date | Country | |
|---|---|---|---|
| 20070002693 A1 | Jan 2007 | US |
