Device for measuring humidity in internal volume of watch case

Abstract

To provide a device for measuring the humidity in an internal volume of a watch case.SOLUTION: A measurement device 10 for measuring the humidity in an internal volume 210 of a case 21 of a watch 20 comprises: a watch 20 comprising a case 21 housing an optical system 22; and a management module 30 external to the case 21. The optical system 22 comprises: a transmitter 220 transmitting 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. The management module 30 comprises a processing unit 31 configured to communicate with the optical system 22 and to process data transmitted thereby, so as to determine the humidity present in the internal volume 210 of the case 21 on the basis of the absorption of the light beam 221 by the water vapor that may be present in the internal volume 210 of the case 21.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a device for measuring parameters utilized in the field of timepieces (eg wristwatches, pocket watches), in particular a device for measuring the humidity in the interior space of a timepiece case.

[0002] In particular, the invention relates to a device for measuring the humidity in the interior space of a watch case. [Background technology]

[0003] Nowadays, all wristwatches are designed to be waterproof, i.e. to withstand the penetration of water in liquid form into the internal space of the case. This means that, depending on the watertightness, the wristwatch can be used in a humid environment or even immersed in water. For example, a diving watch is designed to withstand the pressure generated by water on the walls of its case to a depth of at least 100 meters.

[0004] To ensure water resistance, the watch is fitted with joints that are located at 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 in the environment in which the watch is used, which can lead to a decrease in water resistance: the watch can then become permeable to water, which can cause condensation in the interior spaces and on the surfaces of the components, leading to oxidation of metal components and degradation of polymeric components.

[0006] Also, the joints and / or certain external parts made of polymeric materials may be permeable, i.e. the watch may pass a certain amount of water vapour present in a certain environment, bringing the inside and outside of the watch into equilibrium. This equilibrium may be reached in a few hours or weeks, depending on the construction of the watch, the quality of the joints and the environment. In this case, the amount of vapour present in the watch may vary depending on the wearer and on the different outside temperatures over time.

[0007] To limit the risk of a loss of water resistance or a significant increase in permeability of the polymer materials used, regular maintenance work is recommended for watches, which requires opening the watch, which must be done by a watchmaker and is relatively expensive, since all joints must be systematically replaced.

[0008] For this reason, humidity measuring devices have been developed and incorporated into portable watch cases to measure humidity and detect anomalies related to the presence of water or water vapor without opening the case.

[0009] For example, there are measuring devices in the form of small electronic modules that can measure and record the values ​​of various environmental parameters, including relative humidity. Such electronic modules can measure the humidity inside the watch case via a dedicated sensor. They can then wirelessly transmit the measured relative humidity value to a docking station of the watch.

[0010] However, one of the problems of such measuring devices is that they require a power source such as a battery, and therefore they are not at all suitable for mechanical watches or watches with small size, and in the case of electronic watches, they may limit the autonomy or require the use of large capacity batteries or rechargeable batteries, which may be incompatible with the volume of space inside the watch case.

[0011] It should be noted that the concept of waterproof in this document generally means resistance to water, whether in liquid or vapour form.

[0012] The term "humidity" refers to the relative humidity of the air. Summary of the Invention [Means for solving the problem]

[0013] In this context, the present invention solves the problem by providing a measuring device for measuring the humidity in the internal space of a watch case, comprising a watch with a case housing an optical system, and a management module external to said case, said optical system comprising a light beam transmitter, a multi-pass cell through which the light beam is intended to pass, and a light beam receiver receiving the light beam after it has passed said multi-pass cell, said management module comprising a processing unit in communication with said optical system and adapted to process the data transmitted thereby, thereby determining the humidity present in said internal space of said case based on the absorption of the light beam by water vapour that may be present in said space of said case.

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

[0015] In certain embodiments, the processing unit is configured to control the transmitter to transmit or stop transmitting a light beam.

[0016] In certain embodiments, the transmitter is a vertical cavity surface emitting laser or an external cavity surface emitting laser.

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

[0018] In a particular embodiment, the power source is integrated into the interior space of the watch.

[0019] Other characteristics and advantages of the invention will become apparent from reading the following detailed description, given by way of exemplary embodiments and with reference to figures 1 and 2, without however being limited to these embodiments. [Brief description of the drawings]

[0020] [Figure 1] 1 shows diagrammatically a device for measuring humidity in the interior space of a watch case according to the invention; [Diagram 2] 1 shows diagrammatically a device for measuring humidity in the interior space of a watch case according to the invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] 1 and 2 show diagrammatically a device 10 for measuring humidity in the interior space 210 of a watch case by cavity ring-down spectroscopy. The interior space of the case is defined, in a well-known manner, by a crystal, a back and a middle, and houses a timepiece movement.

[0022] The measuring device 10 according to the invention comprises a watch 20, an optical system 22 housed in a case 21 of the watch 20, and a management module 30 located outside the case 21. The management module 30 is said to be "external" to the case 21 in the sense that it is not housed in the interior space 210 of the case 21.

[0023] The management module 30 comprises a processing unit 31 arranged to communicate with the optical system 22 and to process the data transmitted thereby. The optical system 22 and the management module 30 can preferably communicate by wireless means.

[0024] Advantageously, the management module 30 may further comprise a display member 32 configured to display a representation of the processed data, as will be explained in more detail below.

[0025] The optical system 22 is fixed, for example in the middle, to the face of the watch 20 or to structures of the timepiece movement, such as plates or bridges. As can be seen from the schematic diagrams of figures 1 and 2, the optical system 22 comprises a transmitter 220 which sends a light beam 221, a multipath cell (MPC) through which the light beam 221 is intended to pass, and a receiver 223 intended to receive the light beam 221 after it has passed through the multipath cell 222.

[0026] It should be noted that such an 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 to a medium other than the medium of the internal space 210 of the case 21.

[0027] When the light beam 221 propagates in the medium of the interior space 210 of the watch 20, which in this case is air, it interacts with said medium, thereby changing the properties of this light beam 221.

[0028] In particular, in the present invention, the device aims to measure the humidity present in the interior space 210 of the case 21 of the watch 20, by evaluating the change in absorption of the light beam 221 by water vapour that may be present in the interior space 210 of the case 21. Note that, since the absorbance is measured and the absorption coefficient of water molecules, and in particular water vapour, is known, it is possible to deduce the concentration of water present in the air of the interior space 210.

[0029] Transmitter 220 comprises a collimated light source capable of transmitting a light beam 221 through a multipass cell 222 to a receiver 223. For example, transmitter 220 may be an external cavity surface emitting laser, also known as an external cavity diode laser (ECDL) or a vertical cavity surface emitting laser (VCSEL).

[0030] Advantageously, the transmitter 220 is configured to transmit a light beam 221 having a wavelength that corresponds to one of the wavelengths absorbed by water vapour, in particular 968.3 nm, 1388 nm, 2741.41 nm, 2662.48 nm or 6270.77 nm.

[0031] The transmitter 220 is also configured to communicate with the processing unit 31. In particular, the processing unit 31 is configured to send commands to the transmitter 220 to transmit the light beam 221 or to stop transmitting the light beam 221.

[0032] The multipass cell 222, as shown diagrammatically in figures 1 and 2, comprises at least two reflecting elements 224, which are reflective at the wavelength of the light beam 221, for example made of aluminium oxide or titanium dioxide. Thanks to the configuration of the transmitter 220 and / or the reflecting elements 224, the light beam 221 is reflected multiple times by both reflecting elements 224. The optical path of the light beam 221 is therefore considerably long, which makes it possible to increase the absorption of said light beam 221 by water vapour possibly present in the space, thus improving the sensitivity of the measurement. In particular, the longer the length of the optical path, the more accurate the measurement of humidity by the measuring device 10. By way of example, the multipass cell 222 can be configured such that the optical path is from a few centimetres, for example 10 cm, to a few metres, for example 10 m.

[0033] The receiver 223 comprises an optical light sensor comprising a photodiode and an analog / digital converter for converting an analog value related to the intensity of the light beam 221 into data usable by the processing unit 31, such as a digital value. It is possible that the receiver 223 comprises multiple optical sensors, which allows amplifying the difference between the signals from the optical sensors to reduce the effects of the relative intensity noise of the light beam 221 and to optimize the dynamic range of the analog / digital converter. It is also possible to place an optical bandpass filter in front of the receiver 223 to receive only the wavelengths sent by the transmitter 220.

[0034] The receiver 223 is configured to communicate with the processing unit 31 and to transmit to the processing unit 31 data representative of the intensity of the light beam 221 transmitted by the transmitter 220 .

[0035] The processing unit 31 can be an integrated circuit comprising hardware and software resources, in particular at least one processor associated with memory elements, which are capable of executing instructions for implementing a computer program in order to contribute to determining a measurement of the humidity in the interior space 210 of the case 21 of the watch 20.

[0036] In particular, the processing unit 31 is capable of controlling the transmitter 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 space 210 of the case 21. In particular, the processing unit 31 is capable of performing signal processing operations using signal modulation and synchronous detection operations. The processing unit 31, for example, has in its storage element one or more look-up tables between intensity values ​​of the light beam 221 and / or absorption coefficients of the light beam 221 by water vapor, which include humidity values ​​and / or absorption coefficients associated with intensity values ​​of the light beam 221, thereby determining the humidity in the internal space 210 of the case 21.

[0037] 1, the management module 30 may comprise a power source 33 arranged to power the optical system, 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 may comprise a connector or a plug, respectively, intended to be connected to a plug or a connector, respectively, arranged on the case 21 of the watch 20. The wireless power supply element may also comprise an electromagnetic induction element.

[0038] The display device 32 can be analog or digital. In particular, the display device 32 can advantageously display a plurality of separate visual signals representative of the humidity value determined by the processing unit 31. By way of example, the display device 32 can be constituted by a display screen, a luminous scale, or a needle configured to move in a value scale arranged in an arc, etc.

[0039] It should be noted that typically the embodiments and implementations contemplated above are described as examples, and thus other alternative embodiments and implementations are contemplated.

[0040] In particular, the power source 33 can be mounted in the internal space 210 of the watch 20, as shown in Fig. 2, and not in the management module 30. In this case, such a power source 33 can be formed by a battery or a rechargeable battery having relatively small dimensions. This exemplary embodiment of the invention is preferably applicable to electronic watches, since the battery or the rechargeable battery constituting the power source 33 can be a battery or a rechargeable battery that powers the timepiece movement.

[0041] The management module 30 may also be configured to communicate information representative of the data processed by the processing unit 31 to an electronic device, such as a smartphone or tablet, capable of displaying a representation of the processed data. [Explanation of symbols]

[0042] 10 Measuring Devices 20 Portable Watches 21 cases 22 Optical system 30 Management Module 31 Processing Unit 32 members shown 33 Power Source 210 Interior Space 220 Transmitter 221 Light Beam 222 Multipass Cell 223 Receiver 224 Reflective Elements

Claims

1. A measuring device (10) for measuring the humidity in an interior space (210) of a case (21) of a watch (20), comprising: A portable watch (20) having a case (21) that houses an optical system (22); and a management module (30) located outside the case (21), The optical system (22) comprises a transmitter (220) for transmitting a light beam (221), a multipass cell (222) through which the light beam (221) is intended to pass, and a receiver (223) intended to receive the light beam (221) after it has passed through the multipass cell (222), the management module (30) comprises a processing unit (31) configured to communicate with the optical system (22) and to process data transmitted thereby; This allows determining the humidity present in the interior space (210) of the case (21) based on the absorption of a light beam (221) by water vapor that may be present in the interior space (210) of the case (21). A measuring device (10) characterized in that

2. The processing unit (31) is configured to control the transmitter (220) to transmit or stop transmitting a light beam (221).

2. The measuring device (10) according to claim 1 .

3. The transmitter (220) is a vertical cavity surface emitting laser or an external cavity surface emitting laser.

2. The measuring device (10) according to claim 1 .

4. The management module (30) comprises a power source (33) configured to power the transmitter (220) and the receiver (223).

2. The measuring device (10) according to claim 1 .

5. The power source (33) is integrated into the internal space (210) of the watch (20).

2. The measuring device (10) according to claim 1 .

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