CH701301B1 - Timepiece comprising at least one light source. - Google Patents

Abstract

The invention relates to a timepiece comprising, in addition to a crystal (34), the following covering elements: a back (2), a middle part (1), a dial (3), a bezel (26 ) and two bracelet strands, at least one of these covering elements being at least partially transparent or translucent, the back (2), the middle part (1) and the bezel (26) defining an interior volume (4) of the watch case (6) in which a clock movement (M) is housed, the timepiece being characterized in that it comprises at least one light source (10) housed in the interior volume (4 ) and producing a light which passes through the transparent or translucent part of the trim element concerned.

Description

The present invention relates to a timepiece with special aesthetic effects. More specifically, the present invention relates to a timepiece exhibiting original play of light.

[0002] Creating timepieces such as wristwatches with an improved aesthetic appearance is a constant concern among watch manufacturers and in particular among those responsible for designing the various trim elements. It would take too long to list here all the solutions that have been considered to give a timepiece as neat and aesthetic as possible. By way of example only, we can cite the technique of guillochage of the dials, the shape and/or the color of the appliques of the dial or of the hands or even the addition of precious or semi-precious stones.

The present invention is part of the quest to provide customers with watches whose appearance is both aesthetic and surprising.

[0004] To this end, the present invention relates to a timepiece comprising, in addition to a crystal, at least the following covering elements: a bottom, a middle part, a dial, a bezel and two bracelet strands , at least one of these casing elements being at least partially transparent or translucent, the back, the middle part and the bezel defining an interior volume in which a timepiece movement is housed, the timepiece being characterized in that it comprises at least one light source housed in the interior volume and producing light which passes through the transparent or translucent part of the covering element concerned.

[0005] Thanks to these characteristics, the present invention provides a timepiece whose aesthetic appearance can be varied practically infinitely. Since the light source is housed in the interior volume of the case of the watch, it is for example possible to envisage the middle part being partially or totally transparent, so that the light produced by the light source diffuses through said middle part. Similarly, it may be envisaged to illuminate the sconces at the level of the dial of the watch. To this end, the dial can be provided totally opaque and allow light to escape only at the level of the appliques. It is also possible to cover a transparent dial with an opaque mask which also only allows light to escape at the level of the appliques.

[0006] Different light escape modes can be provided. According to a simplified variant embodiment of the invention, the light produced by the light source directly illuminates the transparent or translucent zones of the trim element(s) through which it is desired that the light emerge. This embodiment is applicable when no obstacle is interposed between the light source and the trim element to be illuminated.

[0007] According to a second variant embodiment, the light source is a light-emitting diode or LED which emits ultraviolet, violet, blue, white or infrared light and the covering element is made of a plastic material loaded with fluorescent and/or phosphorescent particles. In this way, the fluorescent and/or phosphorescent particles absorb the emitted radiation and re-emit a homogeneous visible light. Depending on the type of particles chosen, fluorescent and/or phosphorescent, the luminous effect ceases immediately after the light source has been switched off or, on the contrary, continues through the afterglow effect.

[0008] According to a third alternative embodiment, the light produced by the light source is injected into a light guide which then brings the light to the level of the transparent or translucent zone(s) of the trim element(s) considered. According to a variant, the light guide is an optical fiber which makes it possible to circumvent any obstacles which may arise between the light source and the transparent or translucent zone of the trim element considered through which the light will escape. of the interior volume of the watch case. The optical fiber can be replaced by a fiber which diffuses the injected light over its entire length.

[0009] Preferably, the light source is a light-emitting diode or LED mounted on a support of the printed circuit board or PCB type together with its electronic control circuit. The light source is powered for example by an interchangeable or rechargeable battery or even by a solar cell.

[0010] In places where light must not pass, the covering element concerned may be opaque in the mass or else be coated with a layer of opaque paint.

Other characteristics and advantages of the present invention will emerge more clearly from the detailed description which follows of various embodiments of the invention, these examples being given for purely illustrative and non-limiting purposes only in connection with the appended drawing. on which : Figure 1 is a sectional view of a watch case equipped with a light source according to the invention; FIG. 2 is a partial cross-sectional view of a watch case according to the invention in the region of a push-button; FIG. 3A is a top view of a watch case middle along the inner side of which is fixed a diffusing optical fiber into which light is injected; FIG. 3B illustrates a bundle of optical fibers in which a V-shaped notch is made opposite the light source for optimization of the yield on injection of light into the optical fibers; FIG. 3C illustrates a bundle of optical fibers cut off at a point on its perimeter in order to be able to insert a light source into the space left vacant; FIGS. 3D to 3F illustrate a bundle of optical fibers provided with a plurality of optical extractors which are respectively in the form of V-grooves, microlenses or small printed surfaces, the density of these optical extractors being as much greater the further they are from the light source; FIG. 4 is a top view of a wristwatch comprising a dial through the appliques of which light passes; FIG. 5A is a top view of a wristwatch comprising two bracelet strands in which the light diffuses; FIG. 5B is a view similar to that of FIG. 5A, the transparent parts placed at the places where the strands of the bracelet are fixed to the caseband having a conical shape; FIG. 5C is a view similar to that of FIG. 5A, the transparent parts placed at the places where the strands of the bracelet are fixed to the middle part being constituted by two straight sections of a bar of optical fibers; Figure 6 is a sectional view of a digital display watch case, and FIG. 7 is a view in longitudinal section of a bracelet strand comprising a light guide in which the light diffuses.

The present invention proceeds from the general inventive idea which consists in housing at least one light source in the interior volume of a watch case, the light produced by the light source being able to escape towards the outside of the watch case by at least one watch casing element designed to be at least partially transparent or at least translucent. This provides a timepiece with original aesthetic effects, presenting an extremely attractive appearance in the dark or in the dark.

Figure 1 is a sectional view of a middle part 1 delimiting with a bottom 2 and a dial 3 an interior volume 4 of a watch case 6. For the purposes of this description, it will be imagined that the watch is an electronic watch and that its movement M is arranged in the bottom of the watch case 6. In this way, it is possible to place above the movement M a support plate 8 of the printed circuit board or PCB type on which are mounted a light source 10, for example of the light-emitting diode or LED type, and its electronic control circuit 12. The light source 10 is powered, for example, by a rechargeable or interchangeable battery 14 and conventionally arranged under the clock movement M on the side of the back 2 of the watch case 6. It will be understood that the watch according to the invention can be electronic, electromechanical or even purely mechanical. In the latter case, it will suffice to provide a housing to receive a battery which will be intended to power only the light source 10 and its electronic control circuit 12. Thus, the present invention can be applied to any type of wristwatch, the the only constraint to be observed being that there is no obstacle to the propagation of light between the light source and the covering element through which said light must exit.

According to one embodiment of the invention illustrated in Figure 2, a crown of light is created around a control member of the watch such as a push-button 16. If the middle part 1 is metallic, a through hole 18 is made in the latter in which is engaged a transparent or at least translucent cylinder 20 which will serve as a light guide for the light escaping from the watch case 6. It will be understood that in order to obtain the desired effect, namely to form a crown of light around the head of the push button 16, the outer diameter of the transparent or translucent cylinder 20 must be greater than the outer diameter of the head of the push button 16.

In addition to its light guide function, the cylinder 20 can also serve as a mechanical guide for the push button 16. Of course, it is also possible to introduce into the cylinder 20 an insert which will serve as a mechanical guide for the button. - pusher 16. If the middle part 1 is made of a transparent or translucent material such as a plastic material, a ceramic material, sapphire or fused silica, it can be tinted in the mass except in a region surrounding the button- pusher 16 where the material remains transparent or translucent. It is also possible, to simplify the method of injection of the plastic middle part 1, to tint the latter in the mass throughout its entire volume, then to machine a through hole in which is engaged a transparent or translucent cylinder as explained above in connection with a metal frame. Yet another solution consists in making caseband 1 by injecting a transparent plastic material, then coating the inner face of this caseband with a layer of light-absorbing material except in the region surrounding push-button 16. To vary the effects in particular in the vicinity of the push button 16, it is also possible to overmold a transparent or translucent plastic material on the trim element considered made of an opaque material.

[0016] Any type of light source such as an incandescent lamp, light-emitting diode, organic light-emitting diode or the like can be used. In a particular embodiment of the invention, a light-emitting diode emitting ultraviolet, violet, blue, white or infrared light is used in combination with a middle part made of plastic material loaded with fluorescent and/or phosphorescent particles. In this way, the fluorescent and/or phosphorescent particles absorb the radiation emitted by the diode and re-emit a homogeneous visible light. Depending on the type of particles chosen, fluorescent and/or phosphorescent, the luminous effect ceases immediately after the light source has been switched off or, on the contrary, continues through the afterglow effect.

[0017] The casing element or elements of the watch which allow all or part of the light produced by the light source to pass can be illuminated directly by this light source. These trim elements can nevertheless also be illuminated indirectly by the light source. By way of example, FIG. 3 shows a middle part 1 made of plastic material, along the inner side of which a light guide 22 has been fixed, which makes it possible to bring the light from the point where it is injected into the guide. 22 up to the level of the transparent or translucent zone(s) of the covering element(s) considered through which the light will escape from the interior volume 4 of the watch case 6. According to a variant, the light guide 22 is an optical fiber or a bundle of such optical fibers which makes it possible to circumvent any obstacles which may arise between the light source 10 and the transparent or translucent zone of the trim element in question through which the light will escape from the interior volume 4 of the watch case 6. As illustrated in FIG. 3, the optical fiber can be an optical fiber which diffuses the injected light over its entire length. The light guide can also be a transparent plastic ring with a round or circular section, for example.

According to a first alternative embodiment (FIG. 3B), a V-shaped notch 54 is practiced in the light guide 22 opposite the light source 10. The angle formed by the two arms 54a and 54b of the notch 54 is adjusted according to the light emission cone of the light source 10 to guarantee optimum efficiency for the injection of light into the light guide 22 such as a bundle of optical fibres.

According to a second alternative embodiment illustrated in FIG. 3C, the light guide 22 is cut off at a place 56 of its perimeter and the light source 10 is inserted into the space left vacant between the facing ends 22a, 22b of the light guide 22. Preferably, for the optical coupling between the light source 10 and the light guide 22, the gap between the light source 10 and the end 22a of the light guide 22 which acts as input face of the latter by means of an optical coupling element 57 formed of an optical gel such as a silicone. It is thus possible to guarantee optimum efficiency for the injection of light into the light guide 22.

[0020] The rays of light which propagate inside the light guide 22 at angles less than the limit angle of reflection are totally reflected in the light guide 22. To extract the light from the light guide 22, this light guide 22 is provided with a plurality of optical extractors 58. Depending on the circumstances (see FIGS. 3D to 3F), these optical extractors 58 can take the form of V-shaped grooves 60 machined in the surface of the light guide 22 or even microlenses 62 distributed over the surface of light guide 22. The optical extractors 58 can also be formed by small printed surfaces 64 transferred onto the surface of the light guide 22. The optical extractors 58 can also be formed by particles of pigments embedded in the light guide 22. These particles act as so many centers of diffusion and extraction of light. Advantageously, the optical extractors (grooves 60, microlenses 62, particles of pigments or others) can be manufactured at the same time as the light guide 22 by injection of a material, for example plastic. It will be noted that in order to optimally homogenize the density of the light which escapes from the light guide 22 all along the perimeter of the latter, provision can be made to vary the density of the optical extractors 58 (grooves 60, microlenses 62 , particles of pigments or others), this density being all the greater the further the extractors are from the point of injection of the light into the light guide 22.

[0021] So far, the present invention has been described in connection with the caseband as the only covering element. It should be clearly understood that the invention is in no way limited to this single embodiment and that it applies equally to the other trim elements of the watch, such as the back, the dial, the bezel, the flange , the strands of the bracelet and others. Thus, as represented in FIG. 4, it is possible, for example, to illuminate the appliques 24 at the level of the bezel 26 and of the dial 3. light only at the level of the appliques 24. It is also possible to envisage making the bezel 26 and the dial 3 out of a material, for example plastic, transparent or translucent then coating them with a mask in an opaque color which, too, does not allows light to escape only at the appliques 24. Conversely, the dial 3 can be transparent or translucent and the appliques 24 opaque. It is also possible to envisage that the back 2, the middle 1 and the dial 3 are opaque and that only a flange arranged between the bezel 26 and the dial 3 is transparent or translucent, thus creating a luminous ring all around the crystal 34.

In Figure 5A, there is shown another original embodiment of the invention which aims to inject the light produced by the light source 10 in the strands 30 of a transparent or translucent bracelet. To this end, provision is made for an opaque middle part 1 which has two transparent zones 32a and 32b substantially at noon and at six o'clock, that is to say at the places where the strands 30 of the bracelet are fixed to said middle part 1. On the side Inside the watchcase 6, two light sources 10 can each be provided facing one of the two transparent zones 32a, 32b of the middle part 1. The light produced by the two light sources 10 emerges from the watchcase 6 by said two transparent zones 32a, 32b and is injected into the two transparent or translucent strands 30 of the bracelet in which it diffuses. According to a variant, the caseband 1 could be transparent or at least translucent. In this case, a material will preferably be chosen for the caseband 1 whose refractive index is substantially lower than that of the zones 32a, 32b in order to guarantee optimum performance on the injection of light into the strands 30 of the bracelet.

For example (see Figure 5B), the light source 10 may be constituted by a light emitting diode whose typical dimensions are of the order of 0.6 mm. However, the section of a strand 30 of the bracelet at the place where this strand is connected to the caseband 1 of the watch is of the order of 20 to 30 mm. To ensure that the bracelet strand 30 is illuminated over its entire section, the two transparent zones 32a and 32b through which the light diffuses can be given the shape of a cone, the opening at the top of which corresponds to the width of the bracelet strand 30 . One would also take advantage of the cone of the radiation pattern of most commercially available light emitting diodes.

According to a particular embodiment of the invention, the transparent parts 32a and 32b can be constituted by two straight sections 68a, 68b of a bar of optical fibers (see Figure 5C). Such sections are better known by their Anglo-Saxon name "Fiber Optical Plate" or "FOP". These sections make it possible to bring the light produced by the corresponding light source 10 back to their respective output surfaces 66a, 66b facing the two transparent strands 30 of the bracelet.

An exemplary embodiment of a bracelet strand 30 is illustrated in Figure 7. In accordance with this example, the bracelet strand 30 comprises a light guide 48 which preferably extends over the entire length of said strand 30 and in the thickness of which are structured microprisms or microlenses. For optimum efficiency of the injection of light into the guide 48, the end of said guide 48 located on the side of the caseband 1 of the watch is positioned at the same level as the transparent zone 32a of the caseband 1, facing the light source 10. The light guide 48 is molded in a layer 50 of a transparent plastic material such as silicone or polyurethane. This sandwich structure is completed by a decorative sheet 52 arranged above the light guide 48, that is to say on the side of the strand 30 of the bracelet which is not in contact with the user's wrist. The light injected into the guide 48 is deflected by the microprisms or the microlenses and illuminates the decorative sheet 52. This decorative sheet 52 is made of a material compatible with silicone or polyurethane such as PMMA. The decorative patterns present in the decorative sheet 52 can for example be obtained by a molding technique known by its Anglo-Saxon name In Mold Decoration or IMD.

[0026] Figure 6 appended to this patent application shows a sectional view along the 3:00-9:00 axis of a watch case 6 with digital display. As can be seen on examining this figure, the watch case 6 comprises, on the side of the crystal 34, a digital display 36 of the liquid crystal cell type comprising a front substrate 38 extending parallel to and at a distance a rear substrate 40. The front 38 and rear 40 substrates are joined together by a sealing frame 42 which delimits a sealed volume for the confinement of the liquid crystal. The liquid crystal cell 36 is a so-called back-illuminated cell, that is to say it comprises a light guide 44, for example curved, arranged on the side of the rear substrate 40 and which follows the outer contour of said cell. display 36. The light produced by a light source 10, typically a light-emitting diode or LED, is injected into the light guide 44 and diffuses therein so as to illuminate the display cell 36 and to allow its reading in darkness. In this case, the originality of the invention resides in the fact that the light which escapes through the sides 46 of the light guide 44 is used to illuminate, for example, the transparent or translucent parts of the middle part 1 of the watch. Thus, in accordance with the invention, the light injected into a light guide 44 is used not only to illuminate a liquid crystal display cell 36 from behind but also to illuminate all or part of the trim elements (caseband 1, bezel 26) of a watch case 6.

It goes without saying that various variants and simple modifications can be envisaged by those skilled in the art without departing from the scope of the invention as defined by the appended claims. Thus, as will have been understood from the foregoing, the invention relates to a timepiece comprising, in addition to a crystal, the following covering elements: a back 2, a middle part 1, a dial 3, a bezel 26 and two bracelet strands 30, at least one of these covering elements being at least partially transparent or translucent, the back 2, the middle part 1 and the bezel 26 defining an interior volume 4 of the watch case 6 in which is housed a timepiece M, the timepiece being characterized in that it comprises at least one light source 10 housed in the interior volume 4 and producing light which passes through the transparent part or translucent of the trim element concerned.

When the covering element concerned is made of a transparent or translucent plastic material, it is tinted in the mass except at the place or places where it is desired that the light escapes from the interior volume 4 of the watch case 6. According to a variant, the covering element concerned made of transparent or translucent plastic material can be covered internally or externally with a layer of light-absorbing material except at the place or places where the 'we want the light to escape from the interior volume 4 of the watch case 6.

[0029] In the case where the light source 10 emits ultraviolet, violet, blue, white or infrared light, the covering element is charged with fluorescent and/or phosphorescent particles at the place or places where it is desired that the light escapes from the interior volume 4 of the watch case 6.

As will also be understood from the foregoing, the present invention aims to cause light to escape from the interior volume 4 of the watchcase 6 to the outside. Another aspect of the invention consists in illuminating from the inside 4 of the watch case 6 elements outside the latter. Thus, the caseband 1 can be transparent or at least translucent at least in its parts 32a, 32b opposite the zones where the strands 30 of the bracelet are connected, so that the light which passes through the transparent parts 32a, 32b of the caseband 1 diffuses in the strands 30 of the bracelet which are also transparent or translucent.

According to the other variant embodiment of the invention, the covering element is made of a metallic material. In this case, a through passage is provided in which a transparent or translucent element is engaged at the place or places where it is desired that the light escapes from the interior volume 4 of the watchcase 6. As an For example, when the timepiece includes a winding crown or a push-button 16, a transparent or translucent cylinder 20 is engaged in the through passage 18 which can serve both as a mechanical guide for the winding crown or the push-button 16 and as a light guide for the light which escapes from the interior volume 4 of the watch case 6, the external diameter of the transparent or translucent cylinder 20 being greater than the external diameter of the crown or of the push-button 16 It will be noted that at least the switching on of the light source 10 can be controlled by the user, for example by pressing a push-button such as the push-button 16 or by applying the finger to a tactile key. The extinction of the light source can also be caused by an additional pressure on the push-button 16 or else be controlled by the control circuit 12 after a predetermined time interval. Provision can also be made for the switching on and off of the light source 10 to be controlled by an automatic system such as a photosensitive sensor depending on the degree of ambient light. The photosensitive sensor will control the switching on of the light source when the degree of ambient luminosity drops below a predetermined threshold and will control the extinction of the light source when the degree of ambient luminosity exceeds a predetermined threshold. According to yet another variant, the switching on and off of the light source can be controlled by applying a shock to the watch case or by a sudden movement of the wrist, the shock or the acceleration being detected by an accelerometer housed in the watch.

According to yet another variant, the light produced by the light source 10 is injected into a fiber which diffuses the light over its entire length.

It is also possible to envisage bringing out the light through the dial 3. In this case, the dial 3 is opaque except at the level of the appliques 24 which are transparent or at least translucent and through which the light can escape. of the interior volume 4 of the watch case 6. The dial 3 can be made of an opaque material or else be transparent and be covered in this case with a layer of an opaque material except at the level of the appliques 24.

Claims (21)

1. Timepiece comprising, in addition to a crystal, the following covering elements: a back (2), a middle part (1), a dial (3), a bezel (26) and two strands (30 ) of the bracelet, at least one of these covering elements being at least partially transparent or translucent, the back (2), the middle part (1) and the bezel (26) defining an interior volume (4) of the case watch (6) in which a clock movement (M) is housed, the timepiece being characterized in that it comprises at least one light source (10) housed in the interior volume (4) of the watch case (6) and producing light which passes through the transparent or translucent part of the covering element concerned. 2. Timepiece according to claim 1, characterized in that the covering element concerned is made of a transparent or translucent material chosen from the group formed by plastic materials, ceramic materials, sapphire and fused silica. . 3. Timepiece according to claim 2, characterized in that the covering element concerned is tinted in the mass except at the place or places where it is desired that the light escapes from the interior volume ( 4) of the watch case (6). 4. Timepiece according to claim 2, characterized in that the covering element concerned is covered internally or externally with a layer of a light-absorbing material except at the place or places where one wants the light to escape from the interior volume (4) of the watch case (6). 5. Timepiece according to any one of claims 1 to 4, characterized in that the light source (10) emits ultraviolet, violet, blue, white or infrared light and in that the element of covering is loaded with phosphorescent and/or fluorescent particles at the place or places where it is desired that the light escapes from the interior volume (4) of the watch case (6). 6. Timepiece according to any one of claims 1 to 5, characterized in that the middle part (1) is transparent or translucent at least in its parts (32a, 32b) opposite the areas where the strands ( 30) of the bracelet, so that the light which passes through the transparent or translucent parts (32a, 32b) of the middle part (1) diffuses into the strands (30) of the bracelet which are also transparent or translucent. 7. Timepiece according to claim 6, characterized in that each bracelet strand (30) comprises a light guide (48) in the thickness of which are structured microprisms or microlenses, the light guide (48) being overmolded in a layer (50) of a transparent plastic material, this sandwich structure being completed by a decorative sheet (52) arranged above the light guide (48), that is to say on the side of the strand (30) of the bracelet which is not in contact with the wrist of the user. 8. Timepiece according to claim 7, characterized in that the layer (50) in which the light guide (48) is molded is made of silicone or polyurethane and in that the decorative sheet (52) is made made of PMMA, the decorative patterns present in the decorative sheet (52) being obtained by an In Mold Decoration molding technique. 9. Timepiece according to claim 1, characterized in that, when the covering element is made of a metallic material, a through passage is provided in which is engaged a transparent or translucent element at the place or at the places where it is desired that the light escapes from the interior volume (4) of the watch case (6). 10. Timepiece according to claim 9 further comprising a winding crown or a push-button, characterized in that the winding crown or the push-button (16) is surrounded by a cylinder (20) transparent or translucent which serves as a light guide for the light which escapes from the internal volume (4) of the watch case (6), the external diameter of the transparent or translucent cylinder (20) being greater than the diameter of the crown or the button- pusher (16). 11. Timepiece according to claim 10, characterized in that the cylinder (20) also serves as a mechanical guide for the winding crown or the push-button (16). 12. Timepiece according to any one of claims 1 to 11, characterized in that at least the ignition of the light source (10) is controlled by the user. 13. Timepiece according to any one of claims 1 to 11, characterized in that the ignition of the light source (10) is controlled by an automatic system. 14. Timepiece according to any one of claims 1 to 13, characterized in that the light produced by the light source (10) is injected into a light guide which then brings the light to the level of the part or parts transparent or translucent of the trim element(s) considered. 15. Timepiece according to claim 14, characterized in that the light guide is an optical fiber (22) which makes it possible to circumvent any obstacles which may arise between the light source (10) and the transparent or translucent part. of the covering element considered through which the light will escape from the interior volume (4) of the watch case (6). 16. Timepiece according to claim 14, characterized in that the light guide is a fiber which diffuses the injected light over its entire length and which makes it possible to circumvent any obstacles which may arise between the light source (10) and the transparent or translucent part of the trim element considered through which the light will escape from the interior volume (4) of the watch case (6) 17. Timepiece according to any one of claims 1 to 16, characterized in that the dial (3) is opaque except at the level of the appliques (24) which are transparent or translucent and through which the light can escape from the interior volume (4) of the watch case (6). 18. Timepiece according to claim 17, characterized in that the dial (3) is made of an opaque material. 19. Timepiece according to claim 17, characterized in that the dial (3) is transparent and is covered with a layer of an opaque material except at the appliques (24). 20. Timepiece according to any one of claims 1 to 16, characterized in that the dial (3) is transparent and in that the appliques (24) are opaque. 21. Timepiece according to any one of claims 1 to 20 comprising, on the side of a crystal (34), a digital display (36) under which is arranged a light guide (44) in which is injected the light produced by a light source (10) for rear illumination of said digital display (36), characterized in that the light which escapes through the sides (46) of the light guide (44) which are opposite the middle part (1) and the back (2) of the watch case (6) passes through the transparent or translucent part of the covering element concerned.