Trim component comprising substrate having local variations in refractive index, and method of producing such trim component

Abstract

To provide a component including several bright and saturated colors over a wide color palette.SOLUTION: A trim component (10) includes a substrate (11) having a trim surface (110). The substrate (11) includes a decorative area (12, 13), a first portion (111) of the trim surface (110) is defined by the decorative area (12, 13), and a remaining portion of the trim surface (110) defines a second portion (112) of the trim surface (110). The first portion (111) of the trim surface (110) has a refractive index different from a refractive index of the second portion (112) of the trim surface (110), the whole of the trim surface (110) is covered with transparent and / or transparent coating (14) with a thickness of between 5 nm and 1 μm so as to give the trim surface (110) interference colors, the color of the first and second portions (111, 112) of the trim surface (110) is different.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the field of watch, jewelry, or ornament manufacturing, and more particularly to trim parts including a substrate with locally varying refractive index.

Background Art

[0002] In the field of watchmaking art, thin films are commonly used to modify the optical properties and thus the aesthetic appearance of the visible surfaces of external components.

[0003] Several methods can be used to deposit thin films, including physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), and galvanic growth methods.

[0004] The thin films can be made of pure metals, metal alloys, or ceramic materials.

[0005] However, these thin films have a relatively limited range of solid colors depending on their composition and thickness.

[0006] By the interference colors obtained by stacking different thin layers (typically made of translucent materials) deposited on a reflective layer, a wide range of colors and highly saturated colors can be obtained.

[0007] All of the aforementioned thin layers are monochromatic, and for multi-color decoration, as many deposition steps as the number of required colors are needed, and these deposition steps are typically followed by intermediate structuring steps performed by photolithography and chemical etching, "lift-off", processes known as "shadow masks", or ablation by laser or reactive ion etching.

[0008] These structuring steps are often cumbersome and costly to ensure compliance with tolerance requirements.

[0009] Accordingly, there is a need to provide components that include some bright saturated colors across a wide color palette. SUMMARY OF THE INVENTION

[0010] The present invention relates to a trim component including a substrate having a trim surface. The substrate includes a decorative area, a first portion of the trim surface being defined by the decorative area and the remaining portion of the trim surface defining a second portion of the trim surface. The first portion of the trim surface has a refractive index different from that of the second portion, and the entire trim surface is covered with a transparent or translucent coating having a thickness between 5 nm and 1 μm so as to impart an interference color to the trim surface, the color of the first portion of the trim surface being different from that of the second portion.

[0011] In this document, the color generated by the optical interference phenomenon is referred to as an "interference color".

[0012] In this way, a wide range of intense saturated colors can be produced in the trim component in a relatively simple manner.

[0013] In certain embodiments, the present invention may further include one or more of the following features, alone or in any technically possible combination.

[0014] In certain embodiments, the decorative area of the substrate has a crystalline phase and the remaining portion of the substrate has an amorphous phase, or vice versa.

[0015] In certain embodiments, the decorative area of the substrate and the remaining portion of the substrate have different crystal structures.

[0016] In certain embodiments, the decorative area of the substrate and the remaining portion of the substrate have different crystal plane orientations.

[0017] In certain embodiments, the decorative area of the substrate has a chemical composition different from that of the remaining portion of the trim surface.

[0018] In certain embodiments, the substrate is made of metal, glass, sapphire, ceramic material, polymer, or metal matrix composite material.

[0019] In certain embodiments, the coating is formed by a layer of oxide, nitride, fluoride, carbide, boride, or a combination of at least two of these elements.

[0020] In certain embodiments, the coating is formed by a stack of layers made of oxide, nitride, fluoride, carbide, and / or a combination of at least two of these elements.

[0021] In certain embodiments, the coating is formed by a stack of layers consisting of two layers of TiO2 with a layer of Al2O3 interposed therebetween.

[0022] In certain embodiments, the coating is configured to impart to the trim part a color characterized in that in the space L*a*b*, L* is between 28 and 60, a* is between -9 and -0.6, and b* is between 21 and 31.

[0023] Another aspect of the present invention relates to a method of providing decoration, for example, on a trim part according to the above. This method includes the step of locally surface-treating the trim surface of the substrate, in which a decorative area is generated on a part of the trim surface of the substrate, this decorative area has a refractive index different from the rest of the trim surface, and this method includes the step of depositing a coating on the entire generated trim surface so that the trim surface has an interference color.

[0024] In certain implementation modes, the step of locally surface-treating is performed by a laser to generate local annealing of the trim surface so as to provide a decorative area by phase change, crystal structure change, surface diffusion, oxidation, reduction, or nitridation.

[0025] In a particular implementation mode, the step of locally surface-treating is performed by electron beam evaporation, ion bombardment, or electron beam lithography so as to cause a local change in the chemical composition of the trim surface to result in a decorative area.

Brief Description of the Drawings

[0026] Other features and advantages of the present invention will become apparent from the following detailed description given by way of example and not by way of limitation with reference to FIG. 1.

[0027]

Figure 1

Mode for Carrying Out the Invention

[0028] The present invention relates to a trim part 10 including a substrate 11 having at least one decorative area 12, 13 in a first portion 111 of a trim surface 110. The substrate 11 can be made of metal, glass, sapphire, ceramic material, polymer, or metal matrix composite material, or more generally any material whose atomic arrangement can be modified. By way of example, the substrate 11 may be made of CrNi, CrC, or an alloy of gold and nickel.

[0029] FIG. 1 shows a trim part 10 having two different decorative areas 12 and 13. However, for ease of reading the text, only one decorative area will be described below.

[0030] The decorative area 12 or 13 is brought about by local surface treatment of the display surface 110. As a result, the decorative area 12 or 13 has a refractive index different from that of the remaining portion of the display surface 110, i.e., the second untreated portion 112 of the display surface 110. In this text, the term surface treatment may also be referred to as volume treatment insofar as it brings about surface treatment. Specifically, as shown in FIG. 1, the surface treatment generates a decorative area 12 or 13 extending into the volume of the substrate 11. As an example, the decorative area 12 or 13 resulting from the surface treatment may extend into the volume of the substrate to a depth equal to 100 μm.

[0031] The entire trim surface 110 is covered with a transparent and / or translucent coating 14, the thickness of which is between 5 nm and 1 μm so as to give an interference color to the trim surface 110. Since the refractive index of the decorative area 12 or 13 (i.e., the first portion 111 of the trim surface 110) is different from the refractive index of the second portion 112 of the trim surface 110, these colors are different, and the decorative area 12 or 13 forms a colored decorative pattern on the trim surface 110.

[0032] The present invention includes several variations for bringing about this colored decorative pattern.

[0033] In a first embodiment, the substrate 11 has an amorphous phase, and by local surface treatment of the trim surface 110, this amorphous phase can be locally converted to a crystalline phase. In this way, the decorative area 12 or 13 has a crystalline phase and the remaining portion of the substrate 11 has an amorphous phase.

[0034] The local surface treatment is preferably carried out by a laser so as to generate local annealing on the trim surface. This annealing may have the effect of locally reducing or oxidizing the surface of the substrate 11.

[0035] Conversely, the substrate 11 can have a crystalline phase, and the local surface treatment of the trimming surface 110 can locally convert the crystalline phase into an amorphous phase. In this way, the decorative area 12 or 13 has an amorphous phase, and the remaining part of the substrate 11 has a crystalline phase. In this example, the substrate 11 can be made of sapphire or diamond.

[0036] In the second embodiment, the decorative area 12 or 13 is made to have a crystal structure different from that of the remaining part of the substrate 11.

[0037] In the third embodiment, the decorative area 12 or 13 is made to have a crystal plane with an orientation different from that of the crystal plane of the remaining part of the substrate 11.

[0038] In these embodiments, these different configurations of the decorative area 12 or 13 are obtained according to the material of the substrate 11 and the laser parameters. Modifying these parameters according to the desired results is within the reach of those skilled in the art.

[0039] In the fourth embodiment of the present invention, the decorative area 12 or 13 is brought about to have a chemical composition different from that of the second part 112 of the trimming surface 110. As an example, the substrate 11 may be locally processed by electron beam evaporation or lithography so as to cause a local change in the chemical composition of the trimming surface in order to bring about the decorative area 12 or 13.

[0040] Specifically, for example, when the substrate 11 is made of a metal alloy or doped crystalline silicon, atoms can move from the substrate 11 to the trimming surface 110. Further, for example, atoms can be lost by evaporation, or atoms can be acquired on the trimming surface 110, for example, by oxidation in the ambient air or by nitridation in a controlled atmosphere.

[0041] The loss or acquisition of atoms can be achieved by sputtering or any other suitable method.

[0042] To obtain at least two different decorative areas 12 and 13 on the trim surface 110, several local surface treatment solutions from those described above are used.

[0043] The coating 14 may be formed by a layer of oxide, nitride, fluoride, carbide, boride, or a combination of at least two of these elements, or may be formed by a stack of these layers. Preferably, it is deposited by the ALD method or the PVD method. Alternatively, it may be deposited by any suitable thin film deposition method.

[0044] Specifically, in one embodiment, the coating 14 is formed by a stack of layers consisting of two TiO2 layers with an Al2O3 layer interposed therebetween. More specifically, the first layer of TiO2 is deposited on the trim surface 110 of the substrate 11 and has a thickness between 5 and 15 nm, and may further have a thickness between 6.5 and 9 nm. The Al2O3 layer is deposited on the first TiO2 layer and has a thickness between 60 and 70 nm, for example, between 62 and 68 nm. Finally, the second TiO2 layer is deposited on the Al2O3 layer and has a thickness between 25 and 35 nm, for example, between 28 and 31 nm.

[0045] These characteristics of the coating 14, in combination with the glass substrate 11, enable the trim part 10 to have a color characterized in the L*a*b* space where L* is between 28 and 60, a* is between -9 and -0.6, and b* is between 21 and 31. Specifically, the trim part 10 has a green color, and the first part 111, that is, the one or more decorative areas 12 and 13, in other words, the first part 111 and the second part 112 of the trim surface 110 each have a different shade of green.

[0046] Generally, the coating 14 may be composed of a stack of layers, each layer having a thickness between 1 and 100 nm, and may be dimensioned such that the coating has a thickness between 5 and 200 nm.

[0047] More generally, it should be noted that the implementation examples and embodiments considered above are described as non-limiting examples, and thus other variations may also be envisioned.

[0048] In this text, the substrate 11 may be composed of a substrate body and a coating deposited on the substrate body. In this case, the trim surface 110 of the substrate 11 is formed by the visible surface of the coating, and the single or plural decorative areas 12 and 13 are formed in the coating.

Claims

1. A trim component (10) including a substrate (11) having a trim surface (110), the substrate (11) comprises a decorative area (12, 13), a first portion (111) of the trim surface (110) is defined by the decorative area (12, 13) and a remaining portion of the trim surface (110) defines a second portion (112) of the trim surface (110), the first portion (111) of the trim surface (110) having a refractive index different from the refractive index of the second portion (112) of the trim surface (110), the entire trim surface (110) being covered with a transparent and / or semi-transparent coating (14) having a thickness between 5 nm and 1 μm so as to give the trim surface (110) an interference color, the first and second portions (111, 112) of the trim surface (110) being different in color, The trim component (10) is characterized in that the decorative areas (12, 13) have a different chemical composition than the remainder of the trim surface (110).

2. The trim component (10) of claim 1, wherein the substrate (11) is made of a metal, a glass, a sapphire, a ceramic material, a polymer, or a metal matrix composite material.

3. The trim component (10) of claim 1, wherein the coating (14) is formed by a layer of an oxide, a nitride, a fluoride, a carbide, a boride, or a combination of at least two of these elements.

4. 2. The trim component (10) of claim 1, wherein the coating (14) is formed by a stack of layers of oxides, nitrides, fluorides, carbides, and / or combinations of at least two of these elements.

5. 5. The trim component (10) of claim 4, wherein the coating (14) is formed by stacking two layers of TiO2 with a layer of Al2O3 interposed therebetween.

6. 2. The trim component (10) of claim 1, wherein the coating (14) is configured to impart a color to the trim component (10) characterized in that, in the space L*a*b*, L* is between 28 and 60, a* is between -9 and -0.6, and b* is between 21 and 31.

7. A method for providing decoration to a trim component (10), comprising the steps of: The method comprises the step of local surface treatment of a trim surface (110) of a substrate (11), in which decorative areas (12, 13) are generated in parts of the trim surface (110) having a refractive index different from that of the remaining part of the trim surface (110), The method includes depositing a coating (14) over the trimmed surface (110) such that the trimmed surface (110) has an interference color; The method is characterized in that the step of localized surface treatment is performed by electron beam evaporation, ion bombardment or electron beam lithography so as to generate a change in the local chemical composition of the trim surface to result in the decorative areas (12, 13).

8. 8. The method according to claim 7, wherein the step of localized surface treatment is performed by a laser to produce a localized annealing of the trim surface to produce the decorative areas (12, 13) by phase change, crystal structure change, surface diffusion, oxidation, reduction or nitridation.

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