EP0721154A1 - Means and method to detect and correct the position of a moving object - Google Patents

Abstract

The system for detecting and correcting the position of mobile wheels in a clock movement includes a transmitter (19) and receiver (20) adjacent to the three wheels (11, 12, 13) which drive the display. The wheel closest to the transmitter includes a reflective region (16) having one angular position, and a hole (17) having a different angular position. The second wheel (12) also has a hole (15), whilst the wheel furthest from the transmitter has a reflective region (14). A pulsed light sent from the transmitter and is periodically reflected by each of the reflective regions to the receiver (20). The pulses received are counted, and decoded (25) enabling determination and correction of the wheel positions.

Description

The present invention relates to a device for detecting and correcting the position of at least two mobiles, at least one of which carries an indicator, in particular of a component of a watch or pendulum movement, formed by at least two wheels with parallel axes and arranged in substantially parallel planes, this detection device comprising at least one transmitter and one receiver arranged close to one another and arranged respectively to emit and to receive a light beam in a direction substantially parallel to the axes of the wheels, at a determined distance from these axes, all the different wheels from the wheel furthest from the transmitter having an opening, the wheel furthest from the transmitter comprising a reflective zone, said openings and said reflecting zone being arranged on circles concentric with these axes, these circles having a radius equal to said determined distance.

The present invention also relates to a method for detecting and correcting the position of at least two mobiles by means of a device as defined above.

There are currently various devices for detecting the position of mobiles, used for example to detect the position of components such as hands or date disks in watches with analog display. One of these devices includes a transmitter and a receiver associated with each group of mobiles. Generally, a first group of mobiles has wheels driving the seconds and minutes indicators, and a second group of mobiles has a wheel driving the hours indicator. The mobiles of the first group being engaged, the positioning of one of the indicators automatically causes the positioning of the other indicator. This device therefore comprises two separate transmission and reception systems. This embodiment has drawbacks from the point of view of the space required inside the watch case, the manufacturing cost and the energy consumption.

Another known detection device comprises only one emitter emitting a light beam separated into two distinct beams by a semi-transparent mirror or a prism. The two beams are picked up by two receivers. This embodiment requires two circuits for processing the information received by the receiver and therefore consumes a lot of energy.

A third detection device using a single transmitter and a single receiver is described in the German publication DE-A-38 28 810 A1. The hour wheel of the watch in which this device is placed carries a combination of reflecting and non-reflecting zones. The minute wheel has an opening and its underside is reflective. The detection of the position of the mobiles corresponds to the reading and interpretation of a binary code. The device must carry out a series of operations to know the position of the mobiles, so that the detection is relatively long and consumes a lot of energy.

Another detection device using a single transmitter and a single receiver is described in the European patent application published under No. EP-A- 0 529 390. This document describes a watch movement in which the hour wheel has a hole crossing, the rest of the lower surface of this wheel being completely reflective. The minutes wheel as well as the seconds wheel also have a through hole, the holes of these three wheels being aligned with a fixed mirror when the three indicators are placed in their reference position. To place the indicators in this reference position, the hour wheel must be moved until the detector no longer receives a light beam. This means that the beam passes through the hole of this wheel and that it does not pass through that of the minutes and seconds wheels. Then move the minutes and seconds wheels while keeping the hours wheel stationary until the detector receives a beam, which means that the incident beam passes through the holes of the three wheels. This device is impractical because it is not possible to distinguish the reflection of the incident beam on the wheel or on the fixed mirror. It is therefore necessary, before placing the mobiles in their reference position, to find a position in which the minute wheels and seconds are not in their reference position while that of the hours is. This operation increases the time and energy consumption during the correction.

The present invention proposes to overcome these drawbacks by providing a device and a method for reliable detection and correction of the position of the mobiles of a watch, the device being small and consuming little energy, the method being simple and rapid.

This object is achieved by a device as defined in the preamble and characterized in that the wheel closest to the transmitter further comprises a reflective zone having a first angular extension, placed on the side of the transmitter at said determined distance from the axis, and in that at least one of said openings has a second angular extension smaller than said first angular extension of the reflective zone of the wheel closest to the transmitter.

According to a preferred embodiment, said reflective zone of the wheel furthest from the transmitter is at said determined distance from the axis at least when the opening of the wheel closest to the transmitter allows passage the light beam from the transmitter.

Said light beam can be a continuous beam or a beam composed of pulses.

The device advantageously comprises an information processing circuit arranged either to measure the duration during which the receiver picks up a light beam or to count the number of pulses received by the receiver.

The processing circuit is also arranged to compare the information received by the receiver with a reference sequence corresponding to the correct positioning of the mobiles.

According to a preferred embodiment, the processing circuit includes a counter in which are stored time and / or date information.

According to an advantageous embodiment, the device comprises means for automatically correcting the position of the mobiles, associated with means for receiving radio signals containing time information and / or relating to the date.

The object is also achieved by a process as defined in the preamble and characterized in that, in normal operating mode, the position of the indicators is regularly checked by sending a light beam parallel to the axis of the wheels, by detecting a reflected beam. and distinguishing the reflecting area on which the beam is reflected as a function of the value of a distinction parameter picked up by the receiver.

According to a first embodiment of the method, a beam composed of pulses is sent and the number of pulses picked up by the receiver is determined, this number of pulses constituting the value of the distinction parameter.

According to a second embodiment of the method, a continuous beam is sent and the duration during which a reflected beam is picked up by the receiver is determined, this duration constituting the value of the distinction parameter.

Advantageously, the value of the distinction parameter is compared with a reference value corresponding to the correct positioning of the mobiles and the position of the mobiles is corrected in the event of a difference between these two values.

The object of the present invention is also achieved by a method of detecting and correcting the position of at least two mobiles by means of a device as defined in the preamble, characterized in that one places, at high speed , the mobile closest to the transmitter in its initialization position corresponding to the position in which the emitted beam is reflected on the reflective zone of the wheel closest to the transmitter, in that it is checked that the beam is reflected on this area reflecting by measuring the value of a distinction parameter picked up by the receiver, in that the wheel closest to the transmitter is rotated by a determined value so that the emitted beam passes through its opening, in this that the other wheels are rotated at high speed until the beam is reflected on the reflective zone of the wheel furthest from the transmitter, while checking that the beam is reflected on this reflecting zone by measuring the value of said distinction parameter, said other wheels then being in a position called initialization position.

• la figure 1a est une vue schématique en perspective d'un premier mode de réalisation du dispositif selon l'invention, dans lequel la montre ou la pendulette comporte trois mobiles;
• la figure 1b est une vue similaire à la figure 1a, dans laquelle la position des mobiles a été modifiée;
• la figure 2 représente les signaux émis et reçus en fonction de la position des mobiles de la montre ou de la pendulette, illustrés par la figure 1;
• la figure 3 est une vue schématique en perspective d'un deuxième mode de réalisation du dispositif selon l'invention dans lequel la montre ou la pendulette comporte deux mobiles dont l'un porte un indicateur; et
• la figure 4 est une vue similaire à la figure 2, illustrant les signaux émis et reçus en fonction de la position des mobiles représentés à la figure 3.

The present invention and its advantages will appear better in the following description of exemplary embodiments and with reference to the appended drawings, in which:

• Figure 1a is a schematic perspective view of a first embodiment of the device according to the invention, in which the watch or the pendulum comprises three mobiles;
• FIG. 1b is a view similar to FIG. 1a, in which the position of the mobiles has been modified;
• FIG. 2 represents the signals transmitted and received as a function of the position of the mobiles of the watch or of the clock, illustrated by FIG. 1;
• Figure 3 is a schematic perspective view of a second embodiment of the device according to the invention in which the watch or the clock has two mobiles, one of which carries an indicator; and
• FIG. 4 is a view similar to FIG. 2, illustrating the signals transmitted and received as a function of the position of the mobiles represented in FIG. 3.

Figures 1a and 1b illustrate an embodiment of the detection device 10, mounted in a watch comprising three mobiles 11, 12, 13, each of them driving an indicator (not shown). The mobile 11 drives an hour indicator, the mobile 12, a minute indicator and the mobile 13, a seconds indicator. These indicators can for example be formed by needles or discs. The three mobiles have three coaxial wheels with an axis of rotation 18, arranged in substantially parallel planes. These three mobiles are driven by two stepping motors (not shown). The first motor drives the hour 11 and minutes 12 moving parts which are meshed, and the second drives the seconds 13 moving parts.

The wheel of the hour mobile 11 has on its underside a reflective zone 14 disposed at a determined distance from the axis of rotation 18. The wheel of the minute mobile 12 has an opening 15 disposed at said determined distance from the axis of rotation. rotation 18 and the second seconds wheel 13 has a reflective zone 16 having a first angular extension and disposed on its underside, and an opening 17 angularly offset relative to said reflective zone 16 and having a second angular extension. The reflecting zone 16 and the opening 17 are located at said determined distance from the axis of rotation 18. The angular extension of the reflecting zone 16 is defined as being the plane angle whose apex is the point of intersection of the wheel and its axis, and the sides of which are tangent to said reflecting zone. Similarly, the angular extension of the opening is defined similarly, by analogy. The angular extension of the opening 15 is less than or equal to that of the opening 17 and the angular extension of the reflecting area 14 is greater than that of the reflecting area 16. The size of the openings 15 and 17 depends on the frequency of the minutes' mobile steps. This dimension is such that the position of the minutes mobile is uniquely determined, that is to say that it cannot exceed an angular step of elementary movement of the minutes mobile.

The device 10 further comprises a transmitter 19 and a receiver 20 arranged one next to the other and arranged to transmit and to receive a light beam parallel to the axis of rotation 18, at the determined distance from this axis, so that the reflecting zones 14 and 16 can intercept the light beam and the openings 15 and 17 can allow this beam to pass.

The receiver 20 is connected to a shaping device 21 which in particular comprises a filter and an analog / digital converter, connected to an information processing circuit 22 arranged to manage the operation of the watch. This processing circuit includes in particular a counter which stores the date and time in coded form. The circuit 22 manages the activation of reception means 23 of radio signals containing time information, as well as the operation of the transmitter 19. It also controls the motor driving the seconds mobile. The reception means 23 are well known to those skilled in the art and are essentially formed by an antenna 24 and a decoding device 25.

The operating method of the detection device will be described with reference to a specific embodiment in which the transmitter emits a beam composed of three pulses per second and the minute indicator takes one step every thirty seconds. The angular extension of the reflective zone 16 of the seconds mobile is 18 ° and is denoted a in FIG. 1a, and that of the opening 17 of 3 ° and is denoted b in FIG. 1a. The edges closest to the reflecting zone 16 and the opening 17 are offset by a multiple angle of 6 ° increased by 1.5 °, that is to say by 13.5 ° and is denoted c in FIG. 1a. The angular extension of the opening 15 is 3 ° and that of the reflective zone 14, 30 °, which corresponds to the angular displacement carried out by the hour wheel for one hour and allows the hour wheel to be mounted without pre -positioning.

When a power source is introduced into the watch, the antenna 24 picks up a signal containing time information from a transmitter, in a manner known to those skilled in the art. This signal is decoded by the decoding device 25 and sent to the processing circuit 22.

Simultaneously, the processing circuit starts the two stepping motors so as to place the indicators in their initialization position as defined below. While the transmitter 19 emits a light beam, the seconds mobile 13 rotates at high speed until the receiver 20 picks up a sequence of nine pulses, which means that the reflective zone 16 has passed in the path of the beam. The mobile 13 is then pivoted 24 ° in the same direction, then it is immobilized. In this position, the beam passes through the opening 17. The minutes 12 and hours 11 mobiles are rotated at high speed until the receiver picks up a reflected beam, which means that the beam passes through the opening 15 and that it is intercepted by the reflecting zone 14. The position of the three mobiles is thus determined and corresponds to the initialization position.

When this position is reached, the processing circuit 22 advances the indicators by supplying a number of pulses to the stepping motors, so that the time displayed by these indicators corresponds to the time provided by the signal containing the timetable information.

In normal operating mode, every minute, the reflective zone 16 of the seconds mobile cuts the light beam. Thus, every minute, the receiver 20 picks up a signal of nine pulses. Similarly, every minute, the light beam passes through the opening 17 of the seconds mobile. This allows the beam to be returned to the receiver only when the aperture 15 and the reflective area 14 are also in the path of the beam, which occurs once every twelve hours. Thus, the receiver picks up nine pulses for three seconds every minute and three pulses for one second every twelve hours as illustrated by FIG. 2 next to the reference R. The counter of the processing circuit 22 checks whether this sequence of impulse is correct. If this is the case, the watch continues to operate in a conventional manner. If the pulse sequence is not correct, it means that one of the stepper motors has not taken a step. This step not taken is caught up by comparing the number of steps actually taken by each motor to the number of steps they should have taken, this number of steps being known by the counter of the processing circuit. It should be noted that in normal operating mode, the transmitter need not continuously emit a pulse. As shown in dashed lines in Figure 2 next to the reference E, the pulses can be produced only when necessary. When the watch is put into operation for the first time, however, it is necessary to send pulses continuous as shown in solid lines in Figure 2 next to the reference E, since the counter contains no information.

FIG. 3 illustrates a second embodiment of a detection device 30 according to the invention. The watch or the clock in which this device is mounted comprises two mobiles 31, 32, the mobile 31 bearing an indication of dates and the mobile 32 being an intermediate mobile formed by a wheel 33 and a pinion 34. The mobile of calendar 31 is driven by meshing with the pinion 34 secured to the wheel 33 which performs one revolution per day in ten consecutive steps having a determined period, for example of one second or less in order to reduce the time for passing to the next calendar. The wheel 33 of the intermediate mobile comprises a reflecting zone 35 having a first angular extension and an opening 36 having a second angular extension and disposed on its underside. The wheel of the date mobile 31 also carries a reflective zone 37 on its underside. This reflective zone 37 has an angular extension corresponding to a one-day increment of the date wheel, which makes it possible not to pre-position the date indicator during assembly. The device 30 comprises, as in the previous embodiment, a transmitter 19 and a receiver 20 connected to a shaping device 21 and a processing circuit 22. Likewise, the device 30 comprises means 23 for receiving signals radios.

The transmitter 19 and the receiver 20 are arranged in such a way that a light beam emitted by this transmitter can be reflected on the receiver both by the reflective zone 35 and by the reflective zone 37 when the opening 36 lets this beam pass. . As in the embodiment described with reference to Figures 1 and 2, the transmitter emits a light beam composed of pulses. These pulses can be sent continuously when the watch is put into operation for the first time, as illustrated in solid lines in FIG. 4 next to the reference E, or intermittently, only when they are used, as is shown in broken lines in Figure 4 next to the reference E. Once a day, the reflective area 35 of the intermediate wheel 33 intercepts the light beam. Assuming that the transmitter emits three pulses per second, that the wheel 33 takes ten consecutive steps of 36 ° for ten seconds and the angular extension of the reflective zone of the intermediate wheel is 72 °, the receiver will capture a sequence of six pulses for locating the position of the intermediate mobile 32. The processing circuit 22 will execute , for example, two additional steps to the intermediate mobile 32, so as to bring the opening 36 into the beam path. Once a month, the opening 36 of the wheel 33 and the reflecting area 37 of the wheel of the date mobile 31 are aligned in the beam of the transmitter. In this position, the receiver 20 also picks up pulses which correspond to the initialization position of the date indicator. As it is required by construction that the angular extension of the reflective zone 35 of the wheel 33 be greater than that of the opening 36, the number of pulses reflected by the reflective zone 37 of the date wheel will be less than the number d pulses reflected by the reflecting zone 35 of the intermediate wheel.

As in the previous embodiment, if the detected sequence does not correspond to the reference sequence, the counter sends information to the processing circuit so as to correct the position of the mobiles.

The present invention is not limited to the embodiment described, but extends to any modification obvious to a person skilled in the art. The pulse beam emitted by the transmitter 19 can for example be replaced in the two embodiments described above by a continuous beam. In this case, the receiver measures the time during which a signal is present instead of measuring the number of pulses it receives. The use of pulses is advantageous since it allows a significant saving of energy.

On the other hand, in normal operation, it is useless to send a beam continuously since the detection device uses the reflected beam only for a short period of time. Thus, it is advantageous to emit a light beam only when necessary, which is known by the processing circuit.

This processing circuit is also arranged to eliminate the received signals comprising fewer pulses than the number of pulses reflected on the reflecting zone of the wheel furthest from the transmitter. This occurs when the opening of the wheel closest to the transmitter comes to the end of the journey when the reflective zone of the wheel furthest from the transmitter is aligned with the light beam. The elimination of this type of signal guarantees correct recognition of the detected signals and acts as a filter.

In the embodiment comprising three mobiles, it is possible, in order to be able to carry out a control every hour, to have on the hour wheel, twelve reflective zones of which eleven have a similar angular extension, the twelfth having a lower angular extension so to distinguish a reference position.

It is also possible to pass the light beam through an opening of the hour wheel 11 or the date wheel 31 and have it received directly by the detector located in this case, facing the transmitter or on a mirror. forming part of the watch or pendulum frame.

With an adaptation of the command sequence of the mobiles for their rapid rotation, the device described allows the use of motors with two directions of rotation.

It is also possible to reverse the reflective and non-reflective areas.

The device therefore allows efficient and simple control of the mobile position of a watch or a pendulum clock and the method is particularly advantageous from the energy point of view.

Claims (14)

Device for detecting and correcting the position of at least two mobiles, at least one of which carries an indicator, in particular of a component of a watch or pendulum movement, formed by at least two wheels with parallel axes and arranged in substantially parallel planes, this detection device comprising at least one transmitter and one receiver arranged close to one another and arranged respectively to emit and to receive a light beam in a direction substantially parallel to the axes of the wheels , at a determined distance from these axes, all the different wheels from the wheel furthest from the transmitter comprising an opening, the wheel furthest from the transmitter comprising a reflecting zone, said openings and said reflecting zone being arranged on circles concentric with these axes, these circles having a radius equal to said determined distance, characterized in that the wheel (13, 33) la closer to the transmitter (19) further comprises a reflective zone (16, 35) having a first angular extension, placed on the side of the transmitter at said determined distance from the axis (18, 38), and in this that at least one of said openings (15, 17, 36) has a second angular extension smaller than said first angular extension of the reflecting zone (16, 35) of the wheel closest to the transmitter. Device according to claim 1, characterized in that said reflecting zone (14, 37) of the wheel furthest from the transmitter (19) is at said determined distance from the axis (18, 38) at least at the time where the opening (17, 36) of the wheel closest to the transmitter lets the light beam from the transmitter pass. Device according to claim 1, characterized in that said light beam is a continuous beam. Device according to claim 1, characterized in that said light beam is a beam composed of pulses. Device according to claim 3, characterized in that it comprises an information processing circuit (22) arranged to measure the duration during which the receiver (20) receives a light beam. Device according to claim 4, characterized in that it comprises an information processing circuit (22) arranged to count the number of pulses received by the receiver (20). Device according to one of claims 3 or 4, characterized in that the processing circuit (22) is arranged to compare the information received by the receiver (20) with a reference sequence corresponding to the correct positioning of the mobiles. Device according to one of claims 3 or 4, characterized in that the processing circuit (22) comprises a counter in which are stored time and / or date information. Device according to claim 1, characterized in that it includes means for automatically correcting the position of the mobiles, associated with means for receiving (23) radio signals containing time information and / or relating to the date. Method for detecting and correcting the position of at least two mobiles by means of a device as defined in one of the preceding claims, characterized in that, in normal operating mode, the position of the indicators is regularly checked by sending a light beam parallel to the axis (18) of the wheels, detecting a reflected beam and distinguishing the reflecting area on which the beam is reflected according to the value of a distinction parameter picked up by the receiver. Method according to claim 10, characterized in that a beam composed of pulses is sent and in that the number of pulses picked up by the receiver (20) is determined, this number of pulses constituting the value of the distinction parameter. Method according to claim 10, characterized in that a continuous beam is sent and in that the duration for which a reflected beam is picked up by the receiver (20) is determined, this duration constituting the value of the distinction parameter . Method according to claims 11 or 12, characterized in that the value of the distinction parameter is compared to a reference value corresponding to the correct positioning of the mobiles and that the position of the mobiles is corrected in the event of a difference between these two values. Method for detecting and correcting the position of at least two mobiles by means of a device as defined in one of the preceding claims 1 to 9, characterized in that the mobile is placed at high speed (13, 32) closest to the emitter (19) in its initialization position corresponding to the position in which the emitted beam is reflected on the reflective zone (16, 35) of the wheel closest to the transmitter, in that we check that the beam is reflected on this reflecting area by measuring the value of a distinction parameter picked up by the receiver, in that we rotate the wheel closest to the transmitter by a value determined so that the emitted beam passes through its opening (17, 36), in that the other wheels are rotated at high speed until the beam is reflected on the reflecting area ( 14, 37) of the wheel furthest from the transmitter, in that the 'it is checked that the beam is reflected on this reflecting area by measuring the value of said distinction parameter, said other wheels being in a position called initialization position.

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