CH710489B1 - Trim element of a timepiece comprising a light sensor. - Google Patents

Abstract

The present invention relates to a trim element for a timepiece comprising a frame made of a first material, said trim element further comprising at least one light sensor (120) characterized in that said light sensor is formed of at least one pellet (122), said pellet being composed of a matrix and a photochromic pigment sensitive to a specific wavelength, said matrix from a binder serving as a support for the pigment, said photochromic pigment being selected to react to a specific intensity of radiation of the specific wavelength so that said pigment changes from a first color to a second color when said specific intensity of radiation is reached.

Description

The present invention relates to a trim element of a timepiece comprising a frame made of a first material, said trim element further comprising at least one light sensor.

TECHNOLOGICAL BACKGROUND

[0002] Portable objects such as watches equipped with sensors allowing the detection of ultraviolet or UV rays are known. These devices include an ultraviolet semiconductor sensor consisting of a GaAsP component combined with a UV filter.

[0003] A disadvantage of these ultraviolet semiconductor sensors is that they have a latency time for display and that they are expensive. Moreover, these sensors being electronic, their use in a mechanical watch is not desired.

Another known possibility consists of a bracelet made of plastic, said plastic of which comprises a photochromic pigment, that is to say one that changes color depending on the light. These photochromic pigments can be chosen to be sensitive to different wavelengths, including ultraviolet.

[0005] A disadvantage of this type of bracelet is that it is of a solid color and that the variation in color depending on the level of UV light takes place around this solid color. It is understood by this that a bracelet whose initial color is green will see its hue vary from a pale green to a dark green depending on the intensity of the ultraviolet light.

[0006] A disadvantage of this type of product is that the indication is not precise since it is difficult to associate a specific shade with a level of ultraviolet luminosity.

SUMMARY OF THE INVENTION

[0007] The invention relates to a covering element which overcomes the aforementioned drawbacks of the prior art by proposing a portable object capable of providing an indication of brightness in a readable and reliable manner, while being simple to implement.

[0008] To this end, the object of the invention is to provide a covering element for a timepiece according to claim 1 comprising a frame made of a first material, said covering element further comprising at least a luminosity sensor, characterized in that said luminosity sensor is formed of at least one pellet, said pellet being composed of a binder and of a photochromic pigment sensitive to a specific wavelength, said photochromic pigment being chosen to respond to a specific intensity of radiation of the specific wavelength so that said pigment changes from a first color to a second color when said specific intensity of radiation is reached.

[0009] This trim element provided with at least one light sensor according to the invention has the advantage of being easily readable since a change in color announces a light intensity threshold crossing. In addition, the use of an energy-intensive electronic system is avoided.

In a first advantageous embodiment, said light sensor is formed of a plurality of pellets, each pellet reacting to a specific intensity of the radiation of the specific wavelength specific to it.

In a second advantageous embodiment, said pellets all have the same first color.

In a third advantageous embodiment, said pellets all have the same second color.

[0013] In a fourth advantageous embodiment, said pellets are designed so that their second color allows a gradient when they have all changed from the first color to the second color.

[0014] In a fifth advantageous embodiment, the pellet is in the form of an ink or paint or lacquer.

In a sixth advantageous embodiment, the pellet is in the form of an insert coated with said photochromic pigment.

In another advantageous embodiment, the pellet is in the form of an insert, said photochromic pigment being dispersed in the material forming said insert.

[0017] In another advantageous embodiment, the armature comprises at least one recess in which the pellet is arranged.

[0018] In another advantageous embodiment, the frame is a bezel.

[0019] In another advantageous embodiment, the armature is a mirror.

[0020] In another advantageous embodiment, the frame is a watch case middle.

[0021] In another advantageous embodiment, the armature is a bracelet.

In another advantageous embodiment, the wristband comprises two wristband strands made of plastic materials, said light sensor being arranged on at least one of the two strands.

In another advantageous embodiment, the bracelet comprises a plurality of links articulated together, said light sensor being arranged on at least one link.

In another advantageous embodiment, said bracelet is closed by a folding clasp, said light sensor being arranged on said clasp.

[0025] In another advantageous embodiment, the armature is a crown.

In another advantageous embodiment, said photochromic pigment is chosen to react to ultraviolet radiation.

BRIEF DESCRIPTION OF FIGURES

The advantages of such a trim element will appear clearly on reading the following description and on examining the drawing which illustrates it by way of example and in which: FIGS. 1 and 2 schematically represent a timepiece comprising a light sensor according to the present invention; FIGS. 3 and 4 schematically represent a bezel forming the trim element comprising a light sensor according to one embodiment of the invention; FIGS. 5 and 6 schematically represent a lens forming the trim element comprising a light sensor according to one embodiment of the invention; FIG. 7 schematically represents a middle part forming the trim element comprising a light sensor according to one embodiment of the invention; FIG. 8 schematically represents a wristband strand forming the trim element comprising a light sensor according to one embodiment of the invention; FIG. 9 schematically represents bracelet strand links forming the trim element comprising a light sensor according to one embodiment of the invention; FIGS. 10 to 11 schematically represent a bracelet clasp forming the trim element comprising a light sensor according to one embodiment of the invention; FIGS. 12 and 13 schematically represent a dial forming the trim element comprising a light sensor according to one embodiment of the invention.

DETAILED DESCRIPTION

The present invention relates to a trim element 1 of a timepiece or watch 100.

The timepiece 100, visible in Figures 1 and 2, is for example a wristwatch and comprises a case 102. This case is formed by a middle part 104 closed by a bottom 106 and a crystal 108. The piece of watchmaking also comprises a bracelet 110. The latter is fixed to the middle via two pairs of lugs 112. The bracelet can be made up of two bracelet strands, each strand being fixed to a pair of horns and connected to the other strand via a clasp.

The trim element 1 comprises a frame made of a first material. This first material can be a metallic or plastic material.

On this frame, at least one light sensor 120 is arranged. This luminosity sensor is used in order to allow the user to visualize at what intensity of luminosity he is compared to a reference. Indeed, the UV index used to inform of the intensity of ultraviolet radiation is known. There is therefore a minimum threshold from which information on this intensity of ultraviolet radiation is visible.

Advantageously according to the invention, the light sensor comprises at least one photochromic patch 122. This photochromic patch is mainly composed of a photochromic pigment such as those defined in patent US5208132 A, which is dispersed in an organic matrix or inorganic. This matrix is a binder serving as a support for the pigment.

[0033] Such a photochromic pigment has a first color and changes color to have a second color when the intensity of the radiation reaches a specific value for said pigment. Here, it will be the intensity of ultraviolet radiation of wavelength 100 to 400nm.

This characteristic makes it possible to visually indicate the crossing of an intensity threshold of the ultraviolet radiation.

[0035] In a preferred embodiment, the luminosity sensor allows the visualization of a luminosity scale. For this, the light sensor comprises a plurality of photochromic patches 122. Each photochromic patch includes a pigment reacting at a specific intensity. Accordingly, each patch 122 changes color when a specific radiation intensity is reached. To have a luminosity scale, the specific intensities of the pellets 122 will be increasing. Thus, when the user carrying the portable object goes into the sun, the pellets change color as they go along, allowing a visual indication. These pads 122 can be glued together or spaced apart.

[0036] In a preferred variant, the different pellets making up the brightness scale have a whole first color, that is to say an identical color at rest. It is understood by this that at a level of luminosity below the minimum threshold, all the pellets have the same color.

[0037] In another preferred variant, the different pellets making up the luminosity scale have an entire second color, that is to say one color, when their specific threshold is reached, which is identical. It is understood by this that at the maximum measurable luminosity, all the pellets will have the same color.

[0038] In another preferred variant, the different pads making up the brightness scale all have an identical first color but are made so that they do not all have an identical second color in order to allow a gradient. More specifically, the pellets are designed so that when they form a brightness scale, the first color changing pellets have a lighter second color than the last color changing pellets. For example, the first pads turn yellow and the last ones turn red. This allows for a double indication: not only does the user know that the brightness is increasing because the number of color-changing pellets increases, but he also knows that he is approaching a maximum intensity because the color varies and becomes darker and darker. .

It will therefore be understood here that the photochromic pigment is of the reversible type. This means that when the pigment reaches or exceeds a specific luminosity threshold, it changes color from a first color to a second color. But it also means that when the luminosity falls below the specific threshold, the pigment changes from the second color to the first color.

[0040] The matrix used for the dispersion of the pigment can be of different kinds.

[0041] A first matrix category includes inks, lacquers and paints. This matrix consists of an elastomeric binder mixed with at least one solvent, one plasticizer and one dispersant. Such a matrix can be a cross-linked polyurethane.

[0042] A second category of matrix comprises thermoplastic granules. This matrix consists of a resin mixed with at least one dispersant and one plasticizer.

[0043] A third category of matrix comprises the rubber compound. This matrix consists of an elastomer mixed with at least fillers, a dispersant and a vulcanization system. This category then makes it possible to produce inserts comprising said photochromic pigment in order to form a mosaic.

[0044] A fourth category of matrix comprises thermosetting mixtures. These mixtures consist of a liquid resin mixed with at least one dispersant.

It is thus possible to obtain a pellet in the form of a transparent organic/inorganic insert (polymethyl methacrylate, acrylic resin, epoxy, glass of raw chemical formula SiO2 or Al2O3 or C). This insert can be screen printed on one side with an ink based on photochromic pigment or have the photochromic pigment dispersed in the material forming the insert.

In a first embodiment, the covering element is a bezel 114 as shown in Figures 3 and 4. This bezel 114 can be a rotating bezel or a fixed bezel. In the case of a fixed bezel, this bezel may be a ring fixed to the caseband so as not to be able to rotate or be directly integrated into the caseband 104 and thus form a caseband-bezel.

Such bezel 114 has an upper wall 114a which is the face visible to the user and a vertical wall 114b allowing the user to rotate the bezel in the case of a rotating bezel.

In this embodiment, the pads 122 comprising the photoelectric pigments are arranged on the upper wall 114a acting as the visible face.

In the case where the pellets 122 are in the form of an ink or paint, these pellets are screen printed on said upper wall. A scale can also be screen-printed to associate a numerical indication with these photochromic patches. Of course, provision can be made for the important values such as 500Lux, 1000Lux, 20000Lux, 100000Lux to be displayed by different dots 122a.

[0050] In the case where the pellets are in the form of an insert, the upper wall 114a of the bezel 114 comprises recesses (not shown). The number of recesses is identical to the number of inserts. The inserts can then be placed and fixed in the recesses by gluing for example. However, it remains possible to directly overmold the inserts in the recesses. A bezel having a bi-material appearance is then obtained when a metal bezel has rubber inserts.

This brightness sensor 120 can be arranged on a quarter of the bezel or a third or half a bezel.

In a second embodiment visible in Figures 5 and 6, the trim element is the glass 108 of the portable object. Such crystal 108 is fixed to middle 104 and has an upper face 108a, a lower face 108b and a side edge 108c for fixing.

In this second embodiment, the photochromic pellets 122 are arranged on the upper face 108a of the crystal. It would be possible to put them on the underside, if the selected transparent material allowed the UV to pass through.

In the case where the pellets are in the form of an ink or paint, these pellets are screen printed on said upper face 108a. A scale can also be screen-printed to associate a numerical indication with its photochromic patches. This scale can also be screen printed on the bezel.

[0055] In a variant, the ice has hollows 108d of very small thicknesses. These recesses make it possible to place the photochromic ink therein while ensuring a perfectly smooth surface of the glass 108, the risks of shocks chipping said ink are therefore reduced.

In the case where the pellets 122 are in the form of an insert, the upper face 108a of the crystal 108 includes recesses 108d. The number of recesses is identical to the number of inserts. The inserts can then be placed and fixed in the recesses by gluing for example. However, it remains possible to directly overmold the inserts in the recesses. A crystal having a bi-material appearance is then obtained.

It is possible, for these two scenarios, for the photochromic patches 122 to be arranged on the upper face of the crystal but for the numerical indications of luminosity to be placed on the dial or on the lower face of the crystal.

In a third embodiment visible in Figure 7, the trim element is the middle part 104 of the portable object.

As for the first and the second embodiment, the photochromic patches in the form of ink or inserts are arranged directly on the middle part or in recesses on said middle part. Numerical indications of luminosity can be screen-printed or engraved on the middle.

[0060] In a fourth embodiment, the covering element is the strap 110 of the watch. Indeed, the timepiece is provided with a bracelet fixed to the case middle via two pairs of lugs.

In a first case visible in Figure 8, the bracelet 110 consists of two bracelet strands 110a, each strand being fixed to a pair of horns 112 and connected to the other strand via a clasp 111. Preferably, the bracelet strands 110a are made of rubber or plastic.

Several solutions are possible for the arrangement of the photochromic patches 122.

A first solution consists in using pellets in the form of ink and depositing this ink on the surface of a bracelet strand.

A second solution consists in using pads in the form of an insert and in placing and fixing these inserts in recesses made in the bracelet strand.

A third solution consists in using pellets in the form of ink and in depositing this ink on a flexible support. This flexible support is then inserted into the bracelet strand so that the pellets are visible.

In a second case visible in Figure 9, the bracelet is made of metal and then consists of a plurality of links 110b attached to each other via pins. This makes it possible to have links 110b which support the photochromic pellets and which can pivot relative to each other.

This bracelet strand also consists of a clasp. This clasp is here in the form of a folding clasp 111. Such a folding clasp is generally composed of three parts 111a, 111b, 111c like longitudinal members and hinged relative to each other. Two of these parts are attached to a link.

These parts making up the folding clasp are then designed to articulate so that they can be stacked, these three parts 111a, 111b, 111c then forming one. This configuration makes it possible to temporarily enlarge the length of the bracelet for attachment to the user's wrist.

The photochromic pellets in the form of ink or inserts are then arranged at the level of the links 110b of said bracelet, directly on the bracelet or in recesses thereof.

Preferably, each link 110b carries a photochromic patch.

[0071]Even more preferentially, the photochromic pellets are arranged on the links placed between the pair of lugs located at 6 o'clock and the folding clasp. Effectively, when a timepiece is on the user's wrist, the links located between the pair of lugs located at 6 o'clock and the folding clasp are the most accessible to the user. The latter just has to slightly turn his wrist to see them. They are even more visible when the user has his arms resting on a table or desk. This arrangement makes it possible not to overload the visual of the dial by having patches on the crystal or the bezel while offering good visibility.

In a fifth embodiment visible in Figures 10 to 12, the covering element is the clasp 111 that is to say the folding clasp of the bracelet. Indeed, such a folding clasp is generally composed of three parts like longerons, hinged relative to each other. Two of these parts are attached to a link. These parts making up the folding clasp are then designed to articulate so that they can be stacked, these three parts then becoming one. For certain folding clasp models, one of the parts acts as the main part 111a because it is this part which accommodates the other two parts 111b, 111c, this so-called main part is the part visible from the outside. From the outside, the user therefore sees a part in the form of a metal plate on which indications such as the name of the brand can be engraved, for example.

Advantageously, the present invention uses this surface for the arrangement of the light sensor. The photochromic patches are therefore arranged on this surface of the central part 111a of the folding clasp as visible in figure 10.

[0074] The photochromic patches can be aligned and associated with a scale of numerical indications. It is however possible that the pellets are configured to have different sizes depending on the luminosity as visible in figure 11. For example, the pellets can take the form of increasingly large strips as the intensity of the radiation increase. As a result, the user is able, without numerical indication, to have reliable information.

In a sixth embodiment visible in Figures 12 and 13, the covering element is the dial of the timepiece. Indeed, given that the crystal of the timepiece is in principle sufficiently transparent, it is possible to deposit the photochromic disc(s) directly on the dial. This configuration advantageously makes it possible to avoid any risk of damage linked to scratches or shocks.

This embodiment is possible if the crystal 108 is not provided with a filter coating so that all the rays of the specific wavelength can be captured by said photochromic patches 122.

It will be understood that various modifications and/or improvements and/or combinations obvious to those skilled in the art can be made to the various embodiments of the invention described above without departing from the scope of the invention defined by the appended claims.

Thus, it is possible for the photochromic pigment to be sensitive to radiation of another wavelength, such as infrared or the visible spectrum. It is also possible to have a luminosity sensor which can preferentially detect UV-A whose wavelength varies from 400 to 315 nm or UV-B whose wavelength varies from 315 to 280 nm, or even UV-C whose wavelength varies from 280 to 100 nm.

It is also possible to have several brightness sensors with each sensor sensitive to a specific wavelength. We are then able to obtain a portable object which could be able to detect UV-A whose wavelength varies from 400 to 315 nm or UV-B whose wavelength varies from 315 to 280 nm, or UV-C whose wavelength varies from 280 to 100 nm.

In another variant, the patch combines the photochromic function with another function. For example, provision may be made to use phosphorescent pigments for applications in diving watches so as to have visibility of the light sensor. In another example, provision may be made to use thermochromic pigments also making it possible to react to a critical temperature threshold caused by the light intensity on the sensor.

Claims (18)

1. Trim element (1) of a timepiece comprising a frame made of a first material, said trim element further comprising at least one light sensor (120), characterized in that said light sensor luminosity is formed of at least one patch (122), said patch being composed of a matrix and a photochromic pigment sensitive to a specific wavelength, said matrix forming a binder serving as a support for the pigment, said pigment photochromic being chosen to react to a specific intensity of radiation of the specific wavelength so that said pigment changes from a first color to a second color when said specific intensity of radiation is reached. 2. Trim element according to claim 1, characterized in that said light sensor is formed of a plurality of pellets, each pellet reacting to a specific intensity of the radiation of the specific wavelength which is specific to it. 3. Trim element according to claim 2, characterized in that said pellets all have the same first color. 4. trim element according to claim 3, characterized in that said pellets all have the same second color. 5. Trim element according to claim 3, characterized in that said pellets are designed so that their second color allows a gradient when they have all changed from the first color to the second color. 6. Trim element according to one of the preceding claims, characterized in that the patch is in the form of an ink or paint or lacquer. 7. Trim element according to claim 6, characterized in that the matrix of the patch is in the form of an insert, said insert being coated on one side with an ink or a paint or a lacquer based on said pigment photochromic. 8. Trim element according to one of claims 1 to 5, characterized in that the pellet is in the form of an insert, said photochromic pigment being dispersed in the material forming said insert. 9. Trim element according to one of the preceding claims, characterized in that the frame comprises at least one recess in which the pellet is arranged. 10. Trim element according to one of the preceding claims, characterized in that the armature is a bezel (114). 11. Trim element according to one of claims 1 to 9, characterized in that the armature is a mirror (108). 12. Trim element according to one of claims 1 to 9, characterized in that the armature is a middle part (104) of a watch case (102). 13. Trim element according to one of claims 1 to 9, characterized in that the armature is a strap (110). 14. Trim element according to claim 13, characterized in that the strap comprises two strands (110a) of strap made of plastic materials, said light sensor being arranged on at least one of the two strands. 15. Trim element according to claim 13, characterized in that the bracelet comprises a plurality of links (110b) hinged together, said light sensor being arranged on at least one link. 16. Trim element according to claim 13, characterized in that said bracelet is closed by a clasp (111) with a folding clasp, said light sensor being arranged on said clasp. 17. Trim element according to one of claims 1 to 9, characterized in that the armature is a crown. 18. Trim element according to one of the preceding claims, characterized in that said photochromic pigment is chosen to react to ultraviolet radiation.