HK1095391B - Electronic watch with compass function - Google Patents

Description

Electronic watch with compass function

Technical Field

The present invention relates to an electronic watch with compass function, comprising a watch movement and an electronic assembly associated with a manual control member, and having a magnetic sensor assembly capable of measuring the direction of the earth's magnetic field with respect to the watch, and having display means comprising a central hand driven by an electric motor so as to indicate time on the dial in a time display mode and north in a compass mode by two said hands fixed and held in opposite positions aligned with each other.

Background

By Tissot SA at T TouchA watch of the type named after the market is the subject of CH patent No.690697 and comprises, in addition to a digital liquid crystal display, an analog display with two hands. The compass comprises a magnetic sensor assembly of the type disclosed in EP patent No.713162, having a radially magnetized rotor and two hall probes arranged in fixed positions. The control member of this multifunction watch comprises three lateral buttons and seven capacitive keys formed by transparent electrodes on the inner surface of the watch glass case. In compass mode, the north direction is continuously indicated by the hour and minute hands being oppositely aligned so as to together form a single hand, sufficiently long to pass through a large part of the dialAnd thus resembles the magnetic needle of a conventional compass. An additional significant advantage of such a magnetic watch is that it indicates north in real time, regardless of any action by the user entering the watch during use of the compass.

This advantage does not exist, for example, in the table or other device provided in EP patent No.871096 which calculates and displays the direction of two consecutive measurements made by a terrestrial satellite positioning system. In fact, according to this system, the direction of the point selected as the target is indicated with respect to a reference axis of the watch, for example the 6 o 'clock-12 o' clock axis of the dial, the user must remain in the direction of movement defined by two successive measuring points. Since such a reference system is not fixed with respect to the ground, any rotational movement of the watch is accompanied by a pointer before measuring the position of the subsequent point and therefore distorts the indication of direction.

Furthermore, EP patent 713162 discloses a compass watch which can indicate a geographic orientation angle comprised between 0 ° and 360 ° via one of two hands, the user having preselected manual control means using the watch. Means are also provided for inputting the declination of the location to convert the magnetic bearing to a geographic bearing. The user can operate his watch so that the pointer indicates north (zero azimuth) or a preselected direction to be advanced, but not both.

Disclosure of Invention

The present invention relates to a magnetic compass rose capable of indicating simultaneously the north direction and in particular the other preselected direction to be followed, in a clear manner avoiding any risk of confusion between these two directions.

There is thus provided a watch of the type stated in the preamble, characterized in that the display means comprise a third hand which displays information relating to time in a time display mode, and the watch comprises means for selecting a direction of advance with respect to north via an operation on the manual control means, and in that in compass mode the desired direction of advance is indicated by the third hand which is arranged and held in an angular position corresponding to the direction of advance with respect to the direction of the two aligned hands. Preferably, the third hand is also the central hand, being thinner than the other two hands, as is the case with the second hand.

Preferably, the display device further comprises a digital display capable of indicating the forward direction value in compass mode and another indication in time display mode.

Since it is easy to recognize that the north is indicated by two aligned hands via the dial, while the heading is indicated by a hand starting from the centre of the dial, the features of the invention enable the person wearing the watch to observe the north and its target direction simultaneously and continuously without confusion between these directions. Furthermore, the numerical indication of the forward direction on the digital display in compass mode allows the user to check whether the forward direction indicated by the pointer is the direction he wishes to have.

In addition, the user may advantageously place the watch on the map so as to orient the map with respect to the north, and check on the map whether the direction of advance indicated by the third pointer actually corresponds to the direction of the place that the user wishes to reach.

Drawings

Further characteristics and advantages of the invention will be understood from the following description, provided by way of non-limiting example with reference to the accompanying drawings, in which:

fig. 1 schematically shows a top surface of a multifunction watch according to the invention in time display mode; and

fig. 2 shows the display of the same table in compass mode.

Detailed Description

The multifunction watch 1 shown in the figures comprises a case comprising a middle part 2 provided with a back cover, a bezel 3 and a glass case 4 indicated by a dial 5. A twelve hour symbol 6 is fixed to the dial to provide an analogue time display by means of a central hand comprising an hour hand 7, a minute hand 8 and a second hand 9. These hands are turned around the centre 10 of the dial via the action of an electric stepping motor, which is able to drive each hand individually in both directions of rotation. The watch also comprises a digital display 13, for example in the form of a Liquid Crystal Display (LCD) placed in an opening of the dial 5. Figure 1 shows schematically a magnetic sensor assembly 12 of the type described in EP patent NO713162 housed in a watch case.

In order to select and operate the various functions of watch 1, three buttons 14, 15 and 16 with electrical contacts are provided, mounted in the central portion 2 of the watch, and seven control keys 20-26, arranged opposite dial 5 and acting as mode selection keys. In the present case, as in the so-called T touch watch, the keys 20-26 are capacitive keys formed by transparent electrodes fixed under the glass envelope 4 and connected to an electronic detection circuit within the watch by a network of transparent conductive paths extending as far as possible to the periphery of the glass envelope. The reader may find a description of such a capacitive key control pointer in EP patent 674247. The keys 20-26 are used to operate six different operating modes a-F of the watch, which are identified by corresponding indicia on the dial. The center key 20 controls a time display mode. Some modes may include multiple sub-modes selected and controlled by different sequences of actions on the capacitive keys and buttons. The result of the operating function can thus be represented by one or more pointers 7-9 of the digital display 13 and/or of the analog display. The watch may also provide a sound signal in some cases.

As shown in fig. 1, in the time display mode the hands 7-9 typically indicate hours, minutes and seconds, while the digital display 13 may provide another indication, e.g. information not related to time, here e.g. the date, but also information related to time, e.g. the time of the second time zone.

The compass mode corresponds for example to the mode D shown in the figures, i.e. the user can switch by placing his finger on the capacitive key 24 after activating the detection circuit of the capacitive key by pressing the central button 15.

The compass of table 1 may be designed and operated as the compass of the T Touch table. In particular, the radially magnetized rotor of the sensor assembly 12 is permanently oriented parallel to the north-south direction of the earth magnetic field and thus acts as a magnetic field amplifier. When the watch is in compass mode, two hall probes arranged perpendicularly to each other supply signals processed by the relative electronic circuits in order to transmit signals representative of the angular orientation of the rotor magnetic shaft with respect to a fixed reference axis within the watch. Preferably, the electronic circuit performs a correction to correspond to the declination of the user's previously input position so that it represents true north, rather than magnetic north. The electric motors driving hands 7 and 8 operate according to this signal so that minute hand 8 forms the same angle with the rotor (making any corrections) with respect to reference axis 28 and to points in north direction N, and so that hour hand 7 points in the diametrically opposite direction, this operation being repeated many times per second, keeping the hands in the correct position with respect to the ground in real time, even in the case of the user moving his watch. As mentioned above, the two aligned hands 7 and 8 appear to form one long hand which extends over a large part of the dial and therefore resembles the magnetic hand of a conventional compass.

At the same time, the electronic circuit of the watch operates the motor driving the seconds hand 9 so as to place it and maintain it in a position forming a constant preselected angle a with the minute hand 8 indicating the north direction. This third pointer 9 thus indicates in real time the user's heading C to be made in order to reach the point he has selected, the heading being the geographic azimuth equal to the angle a. At the same time, the numerical value of the advance direction (here 248 °) is indicated by the digital display 13. Of course, since the angle a remains constant, the three hands 7, 8 and 9 pivot together as a unit with respect to the housing if the latter pivots in its plane. Since the hands 9 start from the centre of the dial, the direction of advance indicated by the hands 9 is clearly different from the indication of the north direction, which is indicated by aligning the hands, like the hands of a conventional compass. The pointer 9 differs from the other two pointers in that it is relatively narrow. In addition, it may carry specific symbols such as dots in the form of arrows as depicted in the figures.

The user may pre-select the direction of travel in the following manner. The watch must first be set to compass mode, as described above. The user increases the forward direction value by pressing button 14 or decreases the value by pressing button 16, the current value being indicated by the numerical display 13. The seconds hand 9 can be made to remain fixed during these operations, but its position can also be adjusted in real time according to the digital indications, which can select the advance direction while the watch is placed on the map, so that the user sees directly on the map those points which correspond to the advance direction. Once the desired direction of advance is displayed, the user validates this value by pressing the button 15, which is stored in the electronic circuit, and the watch operates normally in compass mode. Preferably, after a predetermined time in compass mode, the watch automatically returns to time mode to limit energy consumption. For other aspects, Table 1 may operate as described for the T Touch table.

Those skilled in the art will appreciate that the compass mode display function described hereinbefore may be achieved by different constituent elements. In particular, solid state magnetic sensor assemblies may be used in addition to magnetic sensor assemblies having magnetized rotors. Furthermore, the control members of the watch may differ from those described herein, for example they may comprise a rotary control handle cooperating with an electric switch or with this or a capacitive sensor.

Claims (8)

1. Watch with compass function, said watch (1) comprising an electronic assembly including a watch movement and associated with a manual control member, said watch having a magnetic sensor assembly (12) able to measure the direction of the earth's magnetic field with respect to the watch, and having display means comprising a central hand (7-9) driven by an electric motor, in order to indicate time on the dial in a time display mode, and north (N) in a compass mode by two of said central hands (7, 8) arranged and held in mutual alignment but pointing opposite,

the watch is characterized in that the display means comprise a third hand (9) displaying time information in a time display mode and in that the watch comprises means for selecting a direction of advance with respect to north via an operation on the manual control member (14, 15, 16, 20-26), in compass mode the direction of advance (C) being indicated by the third hand (9), the third hand (9) being set and held in an angular position corresponding to the direction of advance with respect to the direction of the two aligned hands (7, 8).

2. A watch as claimed in claim 1, characterised in that said third pointer (9) is a central pointer.

3. A watch as claimed in claim 2, characterised in that the third pointer (9) is narrower than the other two pointers.

4. Watch according to claim 1 or 2, characterised in that said display means further comprise a digital display (13) able to indicate the value of the heading in a compass mode and another indication in a time display mode.

5. Watch according to claim 4, characterised in that in the forward direction selection mode the digital display (13) indicates successive values of the forward direction in response to an action on said manual control member (14, 16).

6. Watch according to any one of claims 1 to 3, characterised in that said manual control means comprise a mode selection key (20-26) arranged opposite the dial of said watch.

7. Watch according to claim 6, characterised in that the mode selection keys (20-26) are transparent capacitive keys arranged under a glass cover (4) covering the display means.

8. Watch according to claim 6, characterised in that said manual control means comprise three button contacts (14-16) each having the function of increasing, decreasing and validating the selected advance direction value in compass mode.