Device for measuring humidity in an internal volume of a

Abstract

The invention relates to a device (10) for measuring the humidity in an internal volume (210) of a housing (21) of a watch (20), comprising:-a watch (20) comprising a housing (21) housing an optical system (22), the optical system (22) comprises a transmitter (220) emitting a light beam (221), a multi-pass cell (222) through which the light beam (221) is intended to pass, and a receiver (223) intended to receive the light beam (221) once the light beam (221) has passed through the multi-pass cell (222); -a management module (30) outside the housing (21), comprising a processing unit (31) configured to communicate with the optical system (22) and to process the data transmitted thereby, in order to process the light beam (221) on the basis of the absorption of the light beam (221) by water vapour that may be present in the internal volume (210) of the housing (21). The humidity present in the internal volume (210) of the housing (21) is determined by means of the humidity sensor (20).

Description

Technical Field

[0001] The present invention relates to a device for measuring a parameter applied in the watchmaking field, and in particular to a device for measuring humidity in the internal volume of a watch case.

[0002] More specifically, the invention relates to a device for measuring the humidity in the internal volume of a watch case. Background Art

[0003] Today, all watches are designed to be waterproof, i.e. to withstand the penetration of water in liquid form within the internal volume of the watch case. Depending on its water-tightness, this means that the watch can be used in a wet environment or immersed in water. For example, a diving watch is designed to withstand the pressure generated by water on the walls of the watch case at a depth of at least 100 meters.

[0004] In order to ensure water resistance, watches are equipped with joints located in the assembly interfaces of certain case components such as the crystal, bezel, watch back, crown and pushers.

[0005] However, the mechanical properties of the joints change over time and depending on the climatic conditions of the environment in which the watch is used, which can lead to a degradation of the water resistance of the watch. The watch can then become permeable to water and condensation can occur in its internal volume, on the surfaces of its components, which can cause oxidation of metal components or degradation of polymer components.

[0006] Furthermore, joints and / or certain external parts made of polymeric materials may be subject to permeation, i.e. they allow a certain amount of water vapor present in the environment in which the watch is located to pass through, so that equilibrium is reached between the interior and the exterior of the watch. This equilibrium may be achieved in a few hours or weeks, depending on the quality of the watch construction and the joints and the environment. In this case, the amount of vapor present in the watch may vary depending on the wearer and on differences in external temperature over time.

[0007] In order to limit the risk of loss of water resistance or excessive penetration of the polymer materials used, it is recommended to regularly service the watch, during which it must be opened. Opening the watch is relatively costly since it must be done by a watchmaker and involves the systematic replacement of all the joints.

[0008] Therefore, humidity measuring devices have been developed and integrated into watch cases to measure the humidity and detect any anomalies related to the presence of water or water vapor without having to open the case.

[0009] Examples include a measuring device in the form of a small electronic module capable of measuring and recording the values ​​of various environmental parameters, including relative humidity. Such an electronic module is capable of measuring the humidity inside the watch case via a dedicated sensor. The measured relative humidity value can then be wirelessly transmitted to a watch docking station.

[0010] However, a drawback of these measuring devices is that they require an electric power source, such as batteries or cells. These devices are therefore not very suitable for mechanical watches or watches of small dimensions. Moreover, for electronic watches, these devices may penalize autonomy or require the use of cells or rechargeable batteries of larger capacity, which may be incompatible with the volume available inside the watch case.

[0011] It should be noted that the concept of water resistance herein generally refers to resistance to water (whether in liquid or vapor form).

[0012] The term "humidity" refers to the relative humidity of the air. Summary of the invention

[0013] For this purpose, the present invention overcomes the above-mentioned drawbacks by proposing a device for measuring the humidity in the internal volume of a watch case, comprising: - a watch comprising a housing housing an optical system comprising a light beam emitter, a multi-pass cell through which the light beam is intended to pass, and a light beam receiver for receiving the light beam after it has passed through the multi-pass cell; - A management module outside the shell, comprising a processing unit configured to communicate with the optical system and to process the data transmitted thereby in order to determine the humidity present in the internal volume of the shell based on the absorption of the light beam by water vapor that may be present in the internal volume of the shell.

[0014] In particular embodiments, the invention may further comprise one or more of the following features, taken alone or in any combination that is technically possible.

[0015] In a particular embodiment, the processing unit is configured to control the emitter so that it emits the light beam or stops emitting the light beam.

[0016] In a particular embodiment, the emitter is a vertical cavity surface emitting laser or a vertical external cavity surface emitting laser.

[0017] In certain embodiments, the management module includes a power supply configured to power the transmitter and the receiver.

[0018] In certain embodiments, the power source is integrated into the internal volume of the watch. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Other features and advantages of the present invention will become apparent from the following detailed description, which is made with reference to Figure 1 and Figure 2 The exemplary embodiments are given by way of example and are not limiting in any way. Figure 1 and Figure 2 A device for measuring humidity in the inner volume of a watch case according to the invention is schematically shown. DETAILED DESCRIPTION

[0020] Figure 1 and Figure 2 Schematically illustrated is a device 10 for measuring humidity in an inner volume 210 of a watch case by cavity ring-down spectroscopy. The inner volume of the case is defined in a manner known per se by a crystal, a back and a middle part and houses a horological movement.

[0021] The measuring device 10 according to the invention comprises a watch 20, an optical system 22 housed in a case 21 of said watch 20, and a management module 30 outside said case 21. Management module 30 is said to be "outside" case 21 in the sense that it is not housed in the internal volume 210 of case 21.

[0022] The management module 30 comprises a processing unit 31 configured to communicate with the optical system 22 and to process the data transmitted thereby. The optical system 22 and the management module 30 are preferably able to communicate by wireless means.

[0023] Advantageously, the management module 30 may further comprise a display member 32 configured to display a representation of the processed data, as described in more detail below.

[0024] Optical system 22 is, for example, fastened to the middle, to the dial of watch 20, or to a structure of a timepiece movement, such as a plate or a bridge. Figure 1 and Figure 2 As can be seen from the schematic representation in , the optical system 22 includes a transmitter 220 that transmits a light beam 221 , a multi-pass cell (MPC) through which the light beam 221 is intended to pass, and a receiver 223 that is intended to receive the light beam 221 once it has passed through the multi-pass cell 222 .

[0025] It should be noted that such optical system 22 is configured such that the light beam 221 travels between the transmitter 220 and the receiver 223 without being guided by an optical guide (such as an optical fiber or a dielectric waveguide), i.e., without being confined in a medium other than the medium of the internal volume 210 of the housing 21.

[0026] During the propagation of the light beam 221 in the medium of the internal volume 210 of the watch 20 (in this case, air), the light beam 221 interacts with said medium, which causes a change in the properties of said light beam.

[0027] In particular, in the present invention, the device aims to measure the humidity present in the internal volume 210 of the case 21 of the watch 20 by evaluating the changes in the absorption of the light beam 221 by the water vapor that may be present in the internal volume 210 of the case 21. It should be noted that the absorbance is measured and, since the absorption coefficient of water molecules and in particular water vapor is known, the concentration of water present in the air of the internal volume 210 can be deduced.

[0028] Transmitter 220 includes a collimated light source capable of transmitting a light beam 221 through a multipass cell 222 to a receiver 223. Transmitter 220 is, for example, an external cavity surface emitting laser, also known as an external cavity diode laser or ECDL, or a vertical cavity surface emitting laser or VCSEL.

[0029] Advantageously, the emitter 220 is configured to emit a light beam 221 having a wavelength corresponding to one of the wavelengths absorbed by water vapour, in particular a wavelength equal to 968.3 nm, 1388 nm, 2741.41 nm, 2662.48 nm or 6270.77 nm.

[0030] The emitter 220 is also configured to communicate with the processing unit 31. In particular, the processing unit 31 is configured to transmit instructions to the emitter 220 in order to emit the light beam 221 or to stop emitting the light beam 221.

[0031] like Figure 1 and Figure 2Schematically shown, the multi-pass cell 222 includes at least two reflective elements 224, which are made of, for example, aluminum oxide or titanium dioxide, and have a reflectivity at the wavelength of the light beam 221. Due to the arrangement of the transmitter 220 and / or the reflective element 224, the light beam 221 is reflected multiple times by these two reflective elements 224. Therefore, the optical path of the light beam 221 is significantly increased, making it possible to increase the absorption of the light beam 221 by the water vapor that may be present in the volume, and thereby improving the sensitivity of the measurement. More specifically, the greater the length of the optical path, the more accurate the measurement of humidity by the measuring device 10. By way of example, the multi-pass cell 222 can be configured so that the optical path is between a few centimeters (e.g., 10 centimeters) and a few meters (e.g., 10 meters).

[0032] The receiver 223 comprises an optical light sensor comprising a photodiode. The receiver 223 is also provided with an analog-to-digital converter for converting an analog value related to the intensity of the light beam 221 into data, such as a digital value, which can be used by the processing unit 31. It should be noted that the receiver 223 may comprise a plurality of optical sensors, which makes it possible to amplify the differences in the signals from these optical sensors in order to reduce the influence of the relative intensity noise of the light beam 221, or to optimize the dynamic range of the analog-to-digital converter. It is also possible to place an optical bandpass filter in front of the receiver 223, so that the receiver 223 is only sensitive to the wavelengths emitted by the transmitter 220.

[0033] The receiver 223 is configured to communicate with the processing unit 31 in order to transmit data representative of the intensity of the light beam 221 emitted by the transmitter 220 to the processing unit 31 .

[0034] The processing unit 31 may be an integrated circuit comprising hardware and software resources, in particular at least one processor cooperating with memory elements. The processing unit 31 is capable of executing instructions for implementing a computer program to help determine the measurement of humidity in the internal volume 210 of the case 21 of the watch 20.

[0035] More specifically, the processing unit 31 is capable of controlling the emitter 220, as described above, and is configured to evaluate the absorption of the light beam 221 by water vapor that may be present in the internal volume 210 of the housing 21. In particular, the processing unit 31 is capable of performing signal processing operations by means of signal modulation and synchronous detection operations. The processing unit 31 comprises, for example, one or more lookup tables in its memory element, which match the intensity value of the light beam 221 and / or the coefficient of absorption of the light beam 221 by water vapor with the humidity value associated with the intensity value and / or the absorption coefficient of the light beam 221, so as to determine the humidity in the internal volume 210 of the housing 21.

[0036] like Figure 1As shown, the management module 30 may include a power supply 33 configured to power the optical system, and in particular the transmitter 220 and the receiver 223, for example by means of a wired or wireless power supply element. By way of example, the wired power supply element consists of a connector or a plug, respectively intended to be coupled to a connector or a plug arranged on the housing 21 of the watch 20. Moreover, the wireless power supply element may include an electromagnetic induction element.

[0037] The display devices 32 may be analog or digital. In particular, they are advantageously capable of displaying a plurality of different visual signals representing the humidity values ​​determined by the processing unit 31. By way of example, they may consist of a display screen, a luminous scale, or a pointer adapted to travel on a value scale arranged in the form of an arc, etc.

[0038] More typically, it should be noted that the embodiments and implementations considered above have been described by way of non-limiting examples and that other alternative embodiments and implementations are therefore conceivable.

[0039] In particular, the power source 33 may be integrated into the internal volume 210 of the watch 20, rather than being integrated into the management module 30, such as Figure 2 As shown. Such power source 33 can then be formed by a relatively small-sized battery or rechargeable battery. Such an exemplary embodiment of the present invention is preferably applicable to an electronic watch, because the battery or rechargeable battery constituting the power source 33 can be a battery or rechargeable battery that powers a watch movement.

[0040] Furthermore, the management module 30 may be adapted to transmit information representative of the data processed by the processing unit 31 to electronic devices, such as a smartphone or a tablet, which are able to display a representation of the processed data.

Claims

1. A measuring device (10) for measuring the humidity in an inner volume (210) of a case (21) of a watch (20), characterized in that The device comprises: - a watch (20) comprising a housing (21) housing an optical system (22), said optical system (22) comprising an emitter (220) emitting a light beam (221), a multi-pass cell (222) through which said light beam (221) is intended to pass, and a receiver (223) intended to receive said light beam (221) once it has passed through said multi-pass cell (222); - A management module (30) outside the housing (21), comprising a processing unit (31) configured to communicate with the optical system (22) and to process the data transmitted thereby in order to determine the humidity present in the internal volume (210) of the housing (21) based on the absorption of the light beam (221) by water vapor that may be present in the internal volume (210) of the housing (21).

2. The measuring device (10) according to claim 1, wherein the processing unit (31) is configured to control the emitter (220) so that the emitter (220) emits a light beam (221) or stops emitting a light beam (221).

3. The measuring device (10) according to claim 1, wherein the emitter (220) is a vertical cavity surface emitting laser or an external cavity surface emitting laser.

4. The measuring device (10) according to one of the claims 1, wherein the management module (30) comprises a power supply (33) configured to power the transmitter (220) and the receiver (223).

5. The measuring device (10) according to one of the claims 1, wherein the power supply (33) is integrated into the inner volume (210) of the watch (20).

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