TEMPERATURE CONTROL OF A CLOCK

Description

Technical field of the invention

[0001] The invention defined by the attached claim 1 relates to a temperature control device for a timepiece, comprising a first part allowing light to pass through, and a second adjacent to said first part but distant from said first part and defining with it an intermediate chamber of variable dimensions in an axial direction and / or a radial direction depending on the temperature of said first part.

[0002] The invention also relates to a timepiece, in particular a watch, comprising at least one such temperature control device.

[0003] The invention relates to the field of temperature control in a timepiece, in particular a watch, to enable it to operate, without significant alteration of the rate, in an environment subject to large temperature amplitudes, or even to very high or very low temperatures, such as may be encountered in scientific, aeronautical or astronautic applications in particular. Technological background

[0004] The temperature inside a timepiece, particularly a watch, has a direct influence on its operation. Operating clearances must remain compatible with expansion phenomena within the thermal operating range. Oscillator operation, particularly in the case of a mechanical oscillator, is particularly affected by large temperature differences, which is not conducive to applications or experiments that depend on correct and stable time estimation.

[0005] External insulating devices are bulky and can be inconvenient for users.

[0006] Features built into a watch, such as reflective crystals, can make reading its display difficult or even impossible.

[0007] WO 2014 / 105718 A1 discloses systems, methods, and apparatus for modulating light for forming an image on a display. A light modulator of the display may include a substrate, a shutter, a first actuator, and a second actuator. The shutter may be configured to selectively shutter an optical path through the substrate. The first actuator may be configured to move the shutter in a first direction along a first axis in a plane substantially parallel to a plane defined by the substrate, thereby moving the shutter from a first state to a second state. Summary of the invention

[0008] The invention proposes to integrate into a timepiece, and in particular into the reduced volume constituted by a watch case, a device making it possible to regulate the temperature inside this timepiece as best as possible.

[0009] For this purpose, the invention relates to a temperature control device according to the appended claim 1.

[0010] In other words, the temperature control device for a timepiece comprises a first part allowing light to pass through, defining with an adjacent second part an intermediate chamber (9) of variable dimensions depending on the temperature of the first part, the first part comprises first micro-louvers according to a first spatial distribution, the second part comprises second micro-louvers according to a second spatial distribution and substantially facing the first micro-louvers, to overlap partially or totally in certain relative positions between the first part and the second part, to vary the transmission and / or the reflection of the light incident on the first part between a maximum and a minimum.

[0011] In other embodiments: the first micro-louvers and the second micro-louvers are arranged to overlap partially or totally in certain relative positions of said first part with respect to said second part, to vary the transmission and / or the reflection of the light incident on said first part between a maximum and a minimum; said first part has a first coefficient of thermal expansion, which is different from a second coefficient of thermal expansion that said second part has; said first part or said second part is mounted on a third part, which has a third thermal coefficient which is different from a first coefficient of thermal expansion that said first part has and / or from a second coefficient of thermal expansion that said second part has; said first spatial distribution and said second spatial distribution are homothetic or identical;said first micro-louvers are located on a lower surface of said first part, at said intermediate chamber; said second micro-louvers are located on an upper surface of said second part, at said intermediate chamber; said first micro-louvers and / or said second micro-louvers comprise a reflective coating; said first spatial distribution and second spatial distribution, and the dimensions of said first part and said second part are adjusted for maximum reflection at the highest temperatures, and for maximum transmission at the lowest temperatures; said first part comprises at least one first coated and / or structured reflective part, arranged to reflect the light rays oblique with respect to an axial direction of said timepiece and to allow the passage of the light rays in this axial direction;at least one said first reflective part comprises prismatic structures projecting from said first part, arranged according to said first spatial distribution, and each comprising a reflective coating; at least one said first reflective part comprises reflective structures embedded in the thickness of said first part for better abrasion resistance, arranged according to said first spatial distribution, and each comprising a reflective coating; said first part is a protective cover and in that said second part is a watch crystal.;

[0012] The invention also relates to a timepiece, in particular a watch, comprising at least one such temperature control device. Brief description of the figures

[0013] The aims, advantages and characteristics of the invention will appear better on reading the detailed description which follows, with reference to the appended drawings, where: there Figure 1 shows, schematically and in cross-section of a timepiece consisting of a watch, a first part which is a protective cover, above a second part which is a watch glass; an arrow A indicates activation by axial expansion, while an arrow R corresponds to activation by radial expansion; the functional parts of the watch, not shown, are under the second part, that is to say on the side opposite the first part; the figures 2 to 5 show, in a similar way to the Figure 1, the local detail of the relative positioning of micro-louvers that comprise respectively the first part and the second part, respectively the first micro-louvers according to a first spatial distribution, and the second micro-louvers according to a second spatial distribution, which constitute the temperature control device according to the invention, and which are arranged to overlap partially or totally in certain relative positions of the first part with respect to the second part, to vary the transmission and / or the reflection of the light incident on the first part between a maximum and a minimum, and thus vary the temperature, or stabilize it, inside the timepiece; Figures 2 and 4 correspond to a temperature lower than the optimal temperature; and the Figures 3 and 5 correspond to a temperature lower than the optimal temperature; the passage of the position of the Figure 2 to that of the Figure 3 corresponds to a relative axial movement in the axial direction A (movement away from the Figure 3 towards the Figure 2 , approximation in the opposite case); while the passage of the position of the Figure 4 to that of the Figure 5 corresponds to a relative radial movement in the direction R; the Figure 6 represents, in a similar way to the Figure 1 , a variant in which the first part comprises at least one first coated and / or structured reflective part, which is arranged to reflect the light rays oblique with respect to an axial direction of the timepiece, and to allow the passage of the light rays in this axial direction; Figure 7 represents, in a similar way to the Figure 6, a variant in which such a first reflective part comprises prismatic structures projecting from the first part, arranged according to the first spatial distribution, and each comprising a reflective coating; the most inclined rays, visible on the right part of the figure, are reflected outside the user's field of vision, while those located in his field of vision are transmitted towards the display of the watch, which allows the user to read the time or other indications displayed by the watch; the figure 8 represents, in a similar way to the Figure 6 , a variant in which such a first reflective part comprises reflective structures embedded in the thickness of the first part for better abrasion resistance, arranged according to the first spatial distribution, and each comprising a reflective coating; Figure 9represents, in a schematic manner, a timepiece, here a watch, comprising such a temperature control device. Detailed description of the invention

[0014] The invention relates to a temperature control device 100 for a timepiece 1000, comprising a first part 1 allowing light to pass through, and a second part 2 adjacent to the first part 1 but distant from the first part 1 and defining with it an intermediate chamber 9. This intermediate chamber 9 is of variable dimensions in an axial direction A and / or a radial direction R depending on the temperature of the first part 1.

[0015] The invention uses micro-louvers to ensure temperature control in the watch, to ensure regularity of operation when it is a mechanical or electromechanical watch. Each micro-louver, otherwise called a "micro-louver structure" or "micro-louver structured element", is formed in the first or second part. This micro-louver can modify the angle of incidence, the angle of reflection and / or the angle of refraction of the light incident on said first part. The micro-louver can have refractory characteristics or characteristics that modify the direction of the light passing through or reflecting on this micro-louver.

[0016] According to the invention, the first part 1 comprises a plurality of first micro-louvers 10 according to a first spatial distribution, and the second part 2 comprises a plurality of second micro-louvers 20 according to a second spatial distribution and substantially facing the first micro-louvers 10. The first micro-louvers 10 and the second micro-louvers 20 are arranged to overlap partially or totally in certain relative positions of the first part 1 with respect to the second part 2, to vary the transmission and / or reflection of the light incident on the first part 1 between a maximum and a minimum. Each part thus carries a specific spatial distribution of micro-louvers, which thus overlap for a minimum and a maximum of transmission / reflection according to the position of the first part 1 with respect to the second part 2.This device thus makes it possible to vary the temperature, or stabilize it, inside the timepiece according to the relative position of the micro-louvers.

[0017] Movement under the action of temperature is possible if either one part has a different coefficient of thermal expansion than the other part, or if one of the parts is mounted on a third part with a different coefficient of thermal expansion.

[0018] More particularly, the first part 1 has a first coefficient of thermal expansion, which is different from a second coefficient of thermal expansion that the second part 2 has.

[0019] More particularly, the first part 1 or the second part 2 is mounted on a third part, which has a third coefficient of thermal expansion which is different from a first coefficient of thermal expansion which the first part 1 has and / or from a second coefficient of thermal expansion which the second part 2 has. Even more particularly, the third coefficient of thermal expansion is different from both the first coefficient of thermal expansion and the second coefficient of thermal expansion.

[0020] More specifically, the first spatial distribution and the second spatial distribution are homothetic or identical.

[0021] More particularly, the first micro-louvers 10 are located on a lower surface 19 of the first part 1, at the level of the intermediate chamber 9.

[0022] More particularly, the second micro-louvers 20 are located on an upper surface 29 of the second part 2, at the level of the intermediate chamber 9.

[0023] More particularly, the first micro-shutters 10 and / or the second micro-shutters 20 comprise a reflective coating.

[0024] More particularly, for good heat control, the first spatial distribution and second spatial distribution, and the dimensions of the first part 1 and the second part 2, are adjusted for maximum reflection at the highest temperatures, and for maximum transmission at the lowest temperatures.

[0025] There Figure 1shows, schematically and in section, a first part 1 which is a protective cover, above a second part 2 which is a watch glass; arrow A indicates activation by axial expansion, while arrow R corresponds to activation by radial expansion.

[0026] THE figures 2 to 5 show the local detail of the relative positioning of the micro-louvers 10 and 20 which comprise the first part 1 and the second part 2 respectively. Figures 2 and 4 correspond to a temperature lower than the optimal temperature, and the Figures 3 and 5 correspond to a temperature lower than the optimal temperature. The passage of the position of the Figure 2 to that of the Figure 3 corresponds to a relative axial movement in the axial direction A (movement away from the Figure 3 towards the Figure 2 , approximation in the opposite case), while the passage of the position of the Figure 4 to that of the Figure 5corresponds to a relative radial movement in the direction R. For example, the first micro-louvers 10 forming the reflective layer of the first part 1 are made of aluminum oxynitride AlON, with optical transparency greater than 85%, in the wavelength range of 250 to 4000 nanometers (from the near ultraviolet to the middle of the infrared band), while the second micro-louvers 20, which have a higher coefficient of thermal expansion, are made of “Hexalite” or similar.

[0027] It is therefore advantageous to play on the thermal expansion coefficients of the different components, here the glasses, to align the spatial distributions of the micro-louvers, to regulate the radiation flux reaching the surface of the watch, and to thereby regulate the thermal load of the watch.

[0028] More specifically, as seen on the Figure 6, the first part 1 comprises at least one first coated and / or structured reflective part 11, which is arranged to reflect the oblique light rays relative to an axial direction of the timepiece 1000 and to allow the passage of the light rays in this axial direction.

[0029] Spatial distributions may include relief to take advantage of certain incidence-dependent behavior as shown in Figure 7, where at least one such first reflective part 11 comprises prismatic structures 4 projecting from the first part 1, arranged according to the first spatial distribution, and each comprising a reflective coating 41. The most inclined rays, visible on the right part of the figure, are reflected outside the user's field of vision, while those located in his field of vision are transmitted towards the display of the watch, which allows the user to read the time or other indications displayed by the watch.

[0030] More specifically, as seen on the figure 8 and according to the same principle as the Figure 7 , at least one such first reflective part 11 comprises reflective structures 5 embedded in the thickness of the first part 1 for better abrasion resistance, arranged according to the first spatial distribution, and each comprising a reflective coating 51.

[0031] In a variant not illustrated, the timepiece 1000 comprises at least one internal temperature sensor, and an internal control means for comparing the measured temperature to a set temperature, and for controlling an actuator, for example piezoelectric, to move the first part 1 and / or the second part 2 in the axial direction A and / or the radial direction R.

[0032] More specifically, the first part 1 is a protective cover and the second part 2 is a watch crystal. Naturally, other parts of the watch may be suitable for the installation of micro-louvers on two adjacent parts of the watch, such as the bezel, flange, dial, parts of the movement, or others.

[0033] It is understood that the invention makes it possible to use the capacity of light, both to transfer heat, in particular by reflection, and to consult the display of the watch, in particular to read the time. Until now, there has been no differentiation in the spectrum. One could consider that optically closing the watch in a hot state would make it impossible to read its display. However, it is possible to implement coatings which, for example, transmit visible light, and reflect another band such as infrared. Hot mirrors make it possible in particular to transmit ultraviolet or certain frequencies of the visible.For example, hot mirrors are known with high transmission in the 400-690 nanometer band and high reflection in the 750-1125 nanometer band; or transmitting 85% of the visible and reflecting the near infrared and at least 90% of the infrared; or transmitting 80% of the visible and ultraviolet and reflecting 70% of the infrared.

[0034] These arrangements make the micro-shutters permeable to the visible spectrum to allow the user to read the time, even when closed.

[0035] The invention also relates to a timepiece 1000 comprising at least one such temperature control device 100. More particularly, this timepiece 1000 is a watch.

Claims

1. Temperature control device (100) for timepiece (1000), including a first light-transmitting portion (1), and a second portion (2) defining with said first portion (1) an intermediate chamber (9) of variable dimensions in an axial direction (A) and / or a radial direction (R) depending on the temperature of said first portion (1), device in which said first portion (1) includes a plurality of first microlouvers (10) according to a first spatial distribution, and said second portion (2) includes a plurality of second microlouvers (20) according to a second spatial distribution, said first and second portions provided with these first and second microlouvers (10, 20) being configured to move in relation to one another, thus varying the transmission and / or the reflection of said light on said first portion (1) between a maximum and a minimum, said first portion (1) being capable of moving in an axial direction (A) and / or a radial direction (R) relative to said second portion depending on the temperature of this first portion (1).

2. Temperature control device (100), according to claim 1, characterised in that the first microlouvers (10) and the second microlouvers (20) are arranged to superimpose partially or totally in certain relative positions of said first portion (1) in relation to said second portion (2), in order to vary the transmission and / or the reflection of the incident light on said first portion (1) between a maximum and a minimum.

3. Temperature control device (100) according to any one of the preceding claims, characterised in that said first portion (1) has a first thermal expansion coefficient, which is different from a second thermal expansion coefficient of said second portion (2).

4. Temperature control device (100) according to any one of the preceding claims, characterised in that said first portion (1) or said second portion (2) is mounted on a third portion, which has a third thermal expansion coefficient that is different from a first thermal expansion coefficient of said first portion (1) and / or from a second thermal expansion coefficient of said second portion (2).

5. Temperature control device (100) according to any one of the preceding claims, characterised in that said first spatial distribution and said second spatial distribution are homothetic or identical.

6. Temperature control device (100) according to any one of the preceding claims, characterised in that said first microlouvers (10) are located on a lower surface (19) or said first portion (1), at said intermediate chamber (9).

7. Temperature control device (100) according to any one of the preceding claims, characterised in that said second microlouvers (20) are located on an upper surface (29) of said second portion (2), at said intermediate chamber (9).

8. Temperature control device (100) according to any one of the preceding claims, characterised in that said first microlouvers (10) and / or said second microlouvers (20) include a reflective coating9. Temperature control device (100) according to one of claims 1 to 6, characterised in that said first spatial distribution and second spatial distribution, and the dimensions of said first portion (1) and of said second portion (2) are adjusted for a maximum reflection at the highest temperatures, and for a maximum transmission at the lowest temperatures.

10. Temperature control device (100) according to any one of the preceding claims, characterised in that said first portion (1) includes at least one first coated and / or structured reflective portion (11), arranged to send back the oblique light rays in relation to an axial direction of said timepiece (1000) and to allow light rays to pass through in this axial direction.

11. Temperature control device (100) according to claim 10, characterised in that at least one said first reflective portion (11) includes prismatic structures (4) protruding on said first portion (1), disposed according to said first spatial distribution, and each including a reflective coating (41).

12. Temperature control device (100) according to claim 10 or 11, characterised in that at least one said first reflective portion (11) includes reflective structures (5) embedded in the thickness of said first portion (1) for a better abrasion resistance, disposed according to said first spatial distribution, and each including a reflective coating (51).

13. Temperature control device (100) according to any one of the preceding claims, characterised in that said first portion (1) is a protective cover and in that said second portion (2) is a watch crystal.

14. Timepiece (1000) including at least one temperature control device (100) according to any one of the preceding claims.

15. Timepiece (1000) according to claim 14, characterised in that it is a watch.