WO2015106828A1

WO2015106828A1 - Timepiece with at least one photoluminescent component

Info

Publication number: WO2015106828A1
Application number: PCT/EP2014/050989
Authority: WO
Inventors: Simon Springer; Pierpasquale Tortora
Original assignee: The Swatch Group Research And Development Ltd
Priority date: 2014-01-20
Filing date: 2014-01-20
Publication date: 2015-07-23
Also published as: JP3208267U; CH710869B1; CN206096773U; DE212014000245U1

Abstract

The invention relates to a timepiece (10) comprising external parts (8) in which is arranged a movement (32). According to the invention, at least one of the movement (32) or the external parts (8) comprises a timepiece- component (14, 16, 18, 20, 22, 24, 26, 28, 30, 34, 36, 38, 40, 42, 44, 46, 48, 0, 52, 54) which body is entirely made of a photoluminescent material permitting the timepiece to enhance its legibility and/or visibility without any further luminous coating.

Description

Timepiece with at least one photoluminescent component

Field of the invention

The present invention relates to a timepiece providing a human visible luminous effect.

Background of the invention

Timepieces, such like wristwatches typically provide some kind of luminous elements. For instance, the hands or the applique of the timepiece can be coated with a phosphorescent or similar material, so as to provide a legibility and/or visibility of the time even in a dark or dimmed environment. Typically, the appliques and/or the hands can be coated with luminous paint made of strontium aluminate.

Such luminous coatings may badly adhere onto particular materials and/or be deteriorated or scratched quickly and/or deposition processes of such coating are not able to reliably form a predetermined pattern on complex surfaces that will resist harsh environment.

Document DE10 2012 004 100 discloses a UV light source that activates fluorescent effect of a waveguide embedded in a hand of an analogue display. The implementation disclosed is very cumbersome and always requires an electrical power source.

Summary of the invention

It is an object of the invention to overcome these drawbacks in proposing a timepiece exhibiting particular and unique luminous properties, which may enhance and which may positively contribute to the aesthetic appearance of such timepieces without any further luminous coating.

Hence, the invention relates to a timepiece comprising external parts in which is arranged a movement characterised in that at least one of the movement or the external parts comprises a timepiece-component which body is entirely made of a photoluminescent material permitting the timepiece to enhance its legibility and/or visibility without any further luminous coating. Advantageously, the timepiece-component of photoluminescent material not only comprises a photoluminescent material on its surface but comprises a bulk, and three-dimensional macroscopically voluminous photoluminescent material. Preferably, the at least one timepiece- component consists of the photoluminescent material and may therefore comprise a homogeneous uncoated structure.

Providing a timepiece with at least one timepiece-component entirely made of or manufactured of a photoluminescent material, a coating of selected components of a timepiece with a phosphorescent or otherwise luminescent material becomes effectively superfluous. Manufacturing and assembly of a respective timepiece may therefore be simplified.

Additionally, the photoluminescent material the timepiece-component is made of may further comprise a particular and attractive outer appearance, which may enhance the aesthetic appearance of the timepiece in its entirety. Additionally, the timepiece-component which is entirely made of a photoluminescent material may feature a much stronger luminous effect compared to a conventional luminous paint applied to a selected area of a timepiece-component. This way, visibility and legibility of the timepiece in a darkened or dimmed environment may be effectively enhanced. Generally, the luminous timepiece-component can be used anywhere in a timepiece. It may replace or substitute almost any component or a part of the latter in a movement or external parts of a timepiece.

According to other features of the invention: - the material of the timepiece-component comprises a crystalline structure and/or a glass and/or a fiber glass and/or a ceramic;

- the material the timepiece-component is made of, comprises or consists of at least one or of a combination of the following materials: Ce-, Tb-doped yttrium-aluminum garnet (YAG), Eu-doped yttrium orthovanadate (YVO₄) and Cr-, Fe- or Ti-doped sapphire (AI2O3);

- the timepiece-component forms at least partially a case, a dial, a crystal, a bezel, a button, a crown, a back cover, an applique, a wristlet, a plate, a bridge, a jewel, a rod, a balance, a wheel, an arbor, pallets, an oscillating weight, an escapement wheel or a spring;

- the timepiece further comprises at least one excitation unit to trigger a luminescent effect of the timepiece-component;

- the excitation unit comprises a UV-light source being activated via the control unit;

- the excitation unit is integrated into an electronically implemented movement;

- the excitation unit is integrated into an illuminating module (66) to be separately assembled to the electronically or mechanically implemented movement.

Brief description of the drawings

Other features and advantages of the present invention will appear more clearly upon reading the following detailed description, made with reference to the annexed drawings, given by way of non-limiting and in with:

- Figure 1 is an exploded view of a timepiece according to the invention;

- Figure 2 is an exploded view of a timepiece movement according to the invention;

- Figure 3 schematically shows the implementation of an excitation unit according to a first embodiment of the invention; - Figure 4 schematically shows the implementation of an excitation unit according to a second embodiment of the invention.

Detailed description of the preferred embodiments

In the illustration of Figure 1 , various components of external part 8 of a timepiece 10 provided as a wristwatch are schematically illustrated. The external parts 8 often comprise a case 12 holding a two strands wristlet 30. The case 12 is closed with a back cover 24 at a lower face of the case 12 and a crystal 16 at an upper face of the case 12 so as to protect the watch movement 32. Inside the case 12, between movement 32 and crystal 16, a dial 14 is typically arranged with numerous appliques 26 and hands 28 above said dial 14. The crystal 16 may be held by a bezel 18.

The external parts 8 may further comprise one or several buttons 20 and/or crowns 22 extending for instance from the middle part of the case 12 in order to set the time and/or to activate various functions of the timepiece 10.

In Figure 2 only a few but typical components of a mechanical movement 32 are illustrated. Of course, as explained hereinafter, other kinds of movement such as electronic movement or hybrid electronic - mechanical movement can also be used. The movement 32 typically comprises a plate 34 on which various further components, such like a bridge 36 as well as a variety of moveable and/or mutually inter-engaging components, such like a jewel 38, a rod 40, a balance 42, various wheels 44, an arbor 46, pallets 48, an oscillating weight 50, an escapement wheel 52 as well as a spring 54 can be arranged in a well-defined way. According to the invention, at least one or a part of the above- mentioned components, illustrated in Figures 1 and 2 but also any other functional and/or aesthetic but not explicitly illustrated component of the timepiece 10 may be made of a luminescent material. In particular, the timepiece-component may be a functional component of the timepiece, which provides a particular and well-defined mechanical or electrical function in the present timepiece.

Preferably according to the invention, said luminescent material is able to provide a luminescent response in the human visible range when excited with e.g. natural or non-natural electromagnetic radiation in the UV spectral range.

In a preferred embodiment, the timepiece-component comprises a photoluminescent material. Thus, photoluminescent materials may comprise phosphorescent as well as fluorescent materials. Fluorescent as well as phosphorescent materials are adapted to absorb electromagnetic radiation, in particular in the human visible or UV-spectral range. Absorption of photons then generally leads to the excitation of electrons to higher energy states. The re-emission of a photon leading to a visible luminous effect at the same or at a lower photon frequency is then a consequence of the electron returning into its ground state. Especially with phosphorescent phenomena, the excited electron has to undergo vibrational relaxations and an intersystem crossing to a different spin state. Such decay phenomena are accompanied by luminous emittance at a longer, hence less energetic wavelength compared to the initial wavelength of the exciting radiation. Depending on the particular component or a part of the latter to be replaced by a luminescent material, a suitable luminescent material is to be chosen. Typically, regarding pallets 48, luminescent material can replace pallet-stones and/or anchor lever. Thence, in a particular embodiment, the timepiece-component comprises a monocrystalline structure as well as polycrystalline structure. The luminescent timepiece-component comprises a three-dimensional structure and is provided as a three-dimensional object applicable to replace existing timepiece-components or a part of latters that are usually made of metal, plastic, sapphire, ceramics or glass. In general, the timepiece-component made of a particular luminescent material may also substitute and replace not only metallic and/or plastic components of a timepiece but may also replace and substitute other crystalline and non- luminescent components of existing timepieces comprising or being made e.g. of sapphire or ruby.

Thus, at least one or a part of the above-mentioned timepiece- components 14, 16, 18, 20, 22, 24, 26, 28, 30, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54 may also be made of a different monocrystalline but luminescent material, such like yttrium-vanadate (YVO₄). Other suitable materials may be fluorides, such like YLF, BYF or KYF but also sesquioxides, such like SC2O3 and LU2O3, each of which doped with suitable dopant materials.

It is of particular benefit, that the timepiece-component may be characterized by stimulated emission of electromagnetic radiation, in particular in the human visible spectral range. Such monocrystalline materials may also be able to provide particular mechanical functions. Mechanical hardness of a monocrystalline luminescent material may be comparable to sapphire or ruby and may therefore replace respective sapphire- or ruby-components, e.g. of a mechanical movement of a timepiece. In preferred embodiment, the material, the at least one timepiece-component is made of or comprises at least one of an oxide, a vanadate, a tungstate, a borate, an apatite, a garnet, a sapphire, an aluminate, a sesquioxide, a silicate, a chalcogenide, a fluoride.

For instance, original sapphire components of a timepiece 10 could be replaced and substituted by a doped sapphire, by a doped ruby, by a doped quartz, by a doped diamond or by a doped YAG-crystal. Especially YAG-crystals doped with Nd, Er or Yb provide a large degree of rigidity and a comparatively low absorption in the visible range.

In a further preferred embodiment, the luminescent timepiece- component of the timepiece is doped with at least one dopant being embedded in the bulk of the respective timepiece-component. By appropriately selecting a particular dopant, the spectral range and color of light to be emitted from the timepiece-component can be precisely determined and chosen. Here, not only the choice of a particular dopant but also the dopant concentration in the luminescent material may be arbitrarily modified in order to provide a desired luminous effect for the timepiece. In a further preferred embodiment, the dopant comprises at least one or a combination of the following materials: neodymium (Nd), ytterbium (Yb), erbium (Er), cerium (Ce), Nd:Ce, thulium (Tm), holmium (Ho), dysprosium (Dy), samarium (Sm), terbium (Tb), europium (Eu), chromium (Cr), iron (Fe), titanium (Ti). Generally, monocrystalline oxide luminescent materials, such like yttrium-aluminum garnet (YAG) or yttrium orthovanadate (YVO₄) may be doped with almost any lanthanide or rare-earth material to provide emission in the visible spectral range.

In a further preferred aspect, the material the at least one timepiece- component is made of comprises or consists of any one or a combination of the following materials:

- Ce-, Tb-doped yttrium-aluminum garnet (YAG),

- Eu-doped yttrium orthovanadate (YVO₄)

- Cr-, Fe- or Ti-doped sapphire (AI2O3).

Especially with chromium-doped sapphire, Cr³⁺-ions typically replace aluminum in the sapphire structure.

For instance, Ce(lll):YAG crystals provide a yellow emission, typically between 530 and 550 nm. Moreover, a yellow-green emission spectrum may also be obtained with Tb-doped YAG crystals.

Sapphire-based monocrystalline timepiece-components may exhibit emission spectra in a region above 600 nm, e.g. even near 700 nm or near 800 nm.

Among the above-mentioned tungstates, materials such like potassium gadolinium tungstate (KGW), potassium yttrium tungstate (KYW) may serve as the material of the timepiece-component. Moreover, also fluorides, such like yttrium lithium fluoride (YLF) or calcium fluoride (CAF) as well as borates, e.g. Yb3+Sr3Y(BO3)3 (Yb:BOYS) or apatites, such like S- FAP or SYS may provide a monocrystalline bulk structure to provide and/or to substitute a timepiece-component. Additionally, at least one or a part of the above-mentioned timepiece- components 14, 16, 18, 20, 22, 24, 26, 28, 30, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54 may be manufactured from a luminescent ceramic material, e.g. based on yttrium aluminum garnet (YAG) ceramics. Such ceramic materials may also be doped with suitable lanthanides or rare-earth materials, such like Ce or Tb.

Alternatively or additionally, the at least one luminescent timepiece- component may comprise a glass material, e.g. a silicate glass, a phosphate glass, a fluoride glass, a germanate glass or fluorozirconate, which may be appropriately doped with lanthanide or rare-earth ions. In contrast to a monocrystalline structure, the material of such a timepiece- component may be amorphous. A glass or glass fiber component is available in rather large three-dimensional structures at comparatively low costs. In preferred embodiment, wherein the material of the timepiece- component comprises or consists of a glass, various glass types, such like silicate glass, phosphate glass, fluoride glass, germanate glass and/or fluorozirconate.

The glass-based timepiece-component may be provided in form of a slab or in a form comparable to a fiber laser component having an optical fiber based active gain medium, doped with rare-earth elements, such like lanthanides (La-Lu), erbium (Er), ytterbium (Yb), neodymium (Nd), dysprosium (Dy), praseodymium (Pr), holmium (Ho) and/or thulium (Tm). The doped active gain medium, the timepiece-component is substantially made of, may be at least partially surrounded by at least one layer of a cladding. This way, a luminous effect may even be amplified by the timepiece-component itself. In still another embodiment, the timepiece further comprises at least one excitation unit 60 to trigger a luminescent effect of the luminescent timepiece-component 14, 16, 18, 20, 22, 24, 26, 28, 30, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54 or a part of the latter. For instance, the timepiece 10 may comprise a light source adapted to illuminate the at least one luminescent timepiece-component 14, 16, 18, 20, 22, 24, 26, 28, 30, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54 with electromagnetic radiation outside of the human visible spectral range. In response to a UV-excitation, the luminescent timepiece-component 14, 16, 18, 20, 22, 24, 26, 28, 30, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54 may exhibit a fluorescent or phosphorescent response by emitting electromagnetic radiation within the human visible spectral range.

In the schematic block diagram of Figure 3, the case 12 as well as the movement 32 comprise a timepiece-component 14, 34 made of a luminescent material or consisting of such a material. The diagram of Fig. 3 relates to an electronic timepiece 10, wherein the movement 32 comprises an energy source 64 and a control unit 62. Moreover, the movement 32 comprises an excitation unit 60, e.g. in form a UV-light source, by way of which a luminescent effect of the timepiece-component 14, 34 of the case 12 and/or of the movement 32 can be triggered.

The timepiece-components 14, 34 as indicated in Figure 3 are only exemplary for any one or a part of the timepiece-components 14, 16, 18, 20, 22, 24, 26, 28, 30, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54 as shown in Figures 1 and 2. Hence, instead of the plate 34, an oscillating weight 50 of the movement 32 or any other of the above described components could be implemented as a timepiece-component consisting of or being made of a luminescent material.

By means of the excitation unit 60, a luminous effect of the timepiece- component 14, 34 and hence of the entire timepiece 10 can be provided on command especially in a dark or dim environment. The excitation unit 60 can comprise a UV-light source which is activated via a control unit 62. Typically, the control unit is user operable with help, for example, of a pushbutton 20 or a crown 22, and may further comprise or may be coupled with a source of electric energy 64. By making use of a UV-light source as the excitation unit, excitation of the luminous timepiece-component may occur substantially outside the human visible range. Moreover, based on the time constants of the luminous effect of the timepiece-component dynamic glowing or fading effects may also be implemented. In a particular embodiment of figure 3, the excitation unit 60 is integrated into an electronically implemented movement 32 of the timepiece 10. In this embodiment, the timepiece 10 is preferably designed and implemented as an electronic timepiece 10. Here, the excitation unit 60 may be provided as an additional component in the electronic movement 32. Independent of the implementation of the excitation unit 60, various luminescent timepiece-components 14, 34 may be excited by a single excitation unit 60 at the same time. Hence, a luminescent timepiece- component, which may belong to the external parts 8 of the timepiece 10 may be illuminated and excited by the excitation unit 60 in a similar way as it would be the case for a timepiece-component integrated into the electronic movement.

In another aspect, the excitation unit can be integrated into an illuminating module 66 to be separately assembled to an electronically or mechanically implemented timepiece 10. Especially for a mechanically implemented timepiece the excitation unit 60, the control unit 62 and an energy source 64 may be integrated into a separate module or preassembly, which as a whole may be assembled in or to a mechanical timepiece 10. Also here, the excitation unit 60 does not only serve to optically excite components of the illuminating module but may generally provide illumination and excitation of any luminescent timepiece- component.

Thence, as schematically illustrated in Figure 4, the movement 32 is, in contrast to the configuration of Figure 3, not provided with an electrical energy source 64. In the configuration according to Figure 4 there is provided an illuminating module 66, which comprises an energy source 64, a control unit 62 and an excitation unit 60, e.g. a UV-light source for exciting and/or illuminating the luminescent timepiece-component 34, 14 of the movement 32 and/or of the external parts 8, respectively. As it is additionally illustrated in Figure 4, the illuminating module 66 may also comprise a user interface 68, by way of which an excitation of the luminescent timepiece-component 14, 34 may be triggered on demand. The user interface 68 may comprise a button 20, a crown 22 or the like allowing a user to activate the excitation unit 60, e.g. for a predetermined period of time.

The illuminating module 66 as shown in Figure 4 may be pre- assembled and may be arranged in or at the case 12 of the timepiece 10. Here, it is generally conceivable, that also existing cases 12 and/or mechanical movements 32 could be retrofitted with such an illuminating module 66.

Of course, the present invention is not limited to the illustrated example but may be subject to various variants and alterations, which will be apparent to those skilled in the art. In particular, the invention can be applied in remote fields regarding the horology. For example, it may apply in automotive, aeronautic and/or jewellery domains.

Moreover, in function of chosen luminescent material, manufacturing method can differ. Thus, regarding hard material such as monocrystalline or polycrystalline materials, grinding and/or drilling and/or polishing and/or etching (wet or dry) processes can be performed. In particular case of ceramics, moulding and sintering can be performed. Finally, laser and/or plasma machining can also be performed for most of the hereinbefore materials.

Claims

1 . Timepiece (10) comprising external parts (8) in which is arranged a movement (32) characterised in that at least one of the external parts (8) comprises a timepiece-component (34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54) which body is entirely made of a photoluminescent material permitting the timepiece to enhance its legibility and/or visibility without any further luminous coating.

2. Timepiece (10) according to the preceding claim, characterised in that the timepiece-component forms at least partially a case (12), a dial (14), a crystal (16), a bezel (18), a button (20), a crown (22), a back cover (24), an applique (26) or a wristlet (30).

3. Timepiece (10) comprising external parts (8) in which is arranged a movement (32) characterised in that at least one part of the movement (32) comprises a timepiece-component (14, 16, 18, 20, 22, 24, 26, 28, 30) which body is entirely made of a photoluminescent material permitting the timepiece to enhance its legibility and/or visibility without any further luminous coating.

4. Timepiece (10) according to the preceding claim, characterised in that the timepiece-component forms at least partially a plate (34), a bridge (36), a jewel (38), a rod (40), a balance (42), a wheel (44), an arbor (46), pallets (48), an oscillating weight (50), an escapement wheel (52) or a spring (54).

5. Timepiece according to any of the preceding claims, characterised in that the photoluminescent material of the timepiece- component (14, 16, 18, 20, 22, 24, 26, 28, 30, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54) comprises a crystalline structure.

6. Timepiece (10) according to the preceding claim, characterised in that the photoluminescent material comprises a sapphire (AI2O3) bulk doped with Cr, Fe or Ti atoms.

7. Timepiece (10) according to claim 5, characterised in that the photoluminescent material comprises a yttrium-aluminum garnet (YAG) bulk doped with Ce or Tb atoms.

8. Timepiece (10) according to claim 5, characterised in that the photoluminescent material comprises a yttrium orthovanadate (YVO₄) bulk doped with Eu atoms.

9. Timepiece according to any of the claims 1 to 4, characterised in that the photoluminescent material of timepiece-component (14, 16, 18, 20, 22, 24, 26, 28, 30, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54) comprises a glass and/or a fiber glass.

10. Timepiece according to any of the claim 1 to 4, characterised in that the photoluminescent material of the timepiece-component (14, 16, 18,

20, 22, 24, 26, 28, 30, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54) comprises a ceramic.

1 1 . Timepiece (10) according to any of the preceding claims, characterised in that it further comprises at least one excitation unit (60) to trigger a luminescent effect of the timepiece-component (14, 16, 18, 20, 22, 24, 26, 28, 30, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54).

12. Timepiece (10) according to the preceding claim, characterised in that the excitation unit (60) comprises a UV-light source being activated via the control unit (62).

13. Timepiece (10) according to claim 1 1 or 12, characterised in that the excitation unit (60) is integrated into an electronically implemented movement (32).

14. Timepiece (10) according to any of the preceding claims 1 1 to 13, wherein the excitation unit (60) is integrated into an illuminating module (66) to be separately assembled to the electronically or mechanically implemented movement.