table mirror

Abstract

The invention relates to a watch crystal (1), in particular for a wristwatch, comprising a cover sheet (4) made of diamond. The watch crystal (1) can comprise one layer configured as a bearing sheet (6) having a refractive index lower than the cover sheet (4) and a thickness (503) greater than the wavelength of visible light; and / or at least one layer configured as a coating having a refractive index lower than the cover sheet (4) and a thickness (501) greater than the wavelength of visible light. The invention also relates to a method for manufacturing such a watch crystal (1) and to a watch (40) comprising such a watch crystal (1).

Description

[0001] This invention relates to a watch crystal, and more particularly to a watch crystal for wristwatches.

[0002] Watch crystals made of mineral glass or sapphire glass are known from the prior art.

[0003] The objective of this invention is to provide a watch mirror with good mechanical and optical properties.

[0004] This task is accomplished by a watch crystal having the features described in the independent claim, particularly for wristwatches.

[0005] According to a first advantageous embodiment, the watch crystal (particularly for wristwatches) may include a cover plate made of diamond. Furthermore, the watch crystal includes a layer configured as a support plate with a refractive index lower than that of the cover plate, and / or at least one layer configured as a coating with a refractive index lower than that of the cover plate. The at least one layer configured as a coating is particularly disposed on the inner side of the cover plate. The cover plate forms the outer side of the watch crystal, and the layer configured as a support plate faces the interior of the wristwatch case. Constructing the cover plate from diamond has the advantages of 100% scratch resistance and a high-quality appearance. Another important advantage of the proposed watch crystal will be explained below. Diamond is one of the natural materials with the highest refractive index. In particular, diamond has a refractive index of about 2.41. This causes light passing through a single diamond sheet to lose at least 17% due to reflection (depending on the angle) upon entering the diamond sheet, and at least 17% upon exiting the sheet. When light shines on the hands, numerals, and dial in a watch with only a single diamond crystal, and then returns to the crystal, 17% is lost, and another 17% is lost on its journey back to the observer's eye. The end result is that noticeable haze or darkening affects the observation of the hands and dial because less than 50% of the incident light returns to the observer. By using a layer constructed as a support piece and / or at least one layer constructed as a coating, the effect is achieved where, at the interface between the diamond crystal and the layer constructed as a support piece and / or at least one layer constructed as a coating, the difference in refractive index between the two optical media is no longer as large as it is between a single diamond crystal and air. Therefore, the balance of light is greatly improved. Haze thus appears only to a significantly reduced degree and—depending on the color of the watch dial—is no longer as severe or completely non-disturbing. Preferably, all layers and pieces of the crystal are transparent to visible light.

[0006] It should be understood that sheets and coatings are not to be confused. In other words, a sheet cannot be considered a coating, and a coating cannot be considered a sheet. For example, a diamond sheet and a diamond coating are not the same concept. A sheet, in particular, can exist without support because it is an independent component. In contrast, a coating cannot exist independently and cannot form a complete object; rather, it requires a component / workpiece to which it is applied and thus coated. In particular, a coating can be understood as the result of applying a firmly adhered layer of material from an amorphous material to a workpiece (e.g., a sheet). Coatings can specifically impart certain properties to a workpiece and / or improve its existing properties. At the same time, the workpiece ensures the mechanical stability and functionality of the coating. The adhesion of a coating to the workpiece surface can be achieved through various mechanisms, such as mechanical adhesion or chemical adhesion. In mechanical adhesion, the coating material is anchored in the micropores and depressions of the workpiece surface. Chemical adhesion is based on the chemical bonds between the molecules of the coating material and the workpiece surface.

[0007] The proposed watch crystal is also shatterproof, particularly when it includes a layer constructed as a carrier plate, and the cover plate is manufactured in the case of a single-crystal synthetic diamond cover plate, in the case of a polycrystalline ...

[0008] Advantageously, the cover glass can be the outermost layer of the watch crystal. This specifically means that the surface of the watch crystal is formed by the surface of the cover glass. The outermost layer of the watch crystal, i.e., the surface of the cover glass, is the layer of the watch crystal, i.e., the cover glass surface, into which light first enters when the watch crystal is installed in the watch.

[0009] According to a first advantageous embodiment, the watch crystal preferably further includes a double layer on the outside of the cover plate. This double layer has a diamond layer and an additional layer located between the cover plate and the diamond layer. The refractive index of the additional layer is lower than that of the cover plate and the diamond layer, i.e., lower than the refractive index of the cover plate and lower than the refractive index of the diamond layer. The diamond layer is advantageously thinner than the cover plate. Advantageously, the diamond layer is the outermost layer of the watch crystal. The outermost layer of the watch crystal is the layer on which light first enters when the watch crystal is installed in a wristwatch.

[0010] Each single layer of the double layer preferably has a thickness of less than 5 μm, especially less than 2 μm.

[0011] The layer configured as a carrier sheet and / or at least one layer configured as a coating preferably have a thickness greater than the wavelength of visible light, i.e., greater than all wavelengths of visible light, in other words, greater than the maximum wavelength of visible light.

[0012] The layer configured as a carrier sheet and / or at least one layer configured as a coating preferably has a thickness significantly greater than the wavelength of visible light, preferably greater than 2 μm. This has the effect that no interference effect occurs in the layer configured as a carrier sheet and / or at least one layer configured as a coating.

[0013] The layer configured as a carrier sheet and / or at least one layer configured as a coating, each particularly preferably having a thickness significantly greater than the wavelength of visible light, preferably greater than or equal to 3 μm, especially between 3 μm and 300 μm.

[0014] When at least one layer configured as a coating has multiple coating layers, the value or range of values ​​given for the at least one layer generally applies to all coating layers, rather than to each coating layer individually.

[0015] It should be noted that the wavelength of visible light is in the range of 380nm to 780nm.

[0016] At least one layer configured as a carrier and / or a coating preferably extends to cover at least 80%, more preferably at least 90%, and even more preferably 100% of the watch crystal surface, i.e., covering the entire surface of the watch crystal, especially the entire surface of the inner side of the cover plate. In particular, when the carrier extends to cover 100% of the entire surface of the watch crystal, the carrier is disposed over the entire area of ​​the inner side of the cover plate. Correspondingly, when the coating extends to cover 100% of the entire surface of the watch crystal, the coating is disposed over the entire area of ​​the inner side of the cover plate. When a coating (especially a coating manufactured by PVD (physical vapor deposition)) is provided on the inner side of the cover plate, the coating may alternatively be configured not to cover the entire area of ​​the inner side of the cover plate. In this alternative embodiment, the coating does not extend to the edge of the watch crystal (especially the cover plate), i.e., it terminates before the edge of the watch crystal (especially the cover plate).

[0017] According to a second advantageous embodiment, the watch crystal (particularly for wristwatches) may include a cover plate made of diamond and a double layer located on the outside of the cover plate. The double layer has a diamond layer and at least one additional layer located between the cover plate and the diamond layer. The at least one additional layer preferably has a refractive index lower than that of the cover plate and the diamond layer, i.e., lower than the refractive index of the cover plate and lower than the refractive index of the diamond layer. The diamond layer is advantageously thinner than the cover plate. Advantageously, the diamond layer is the outermost layer of the watch crystal. The outermost layer of the watch crystal is the layer on which light first enters when the watch crystal is installed in a wristwatch.

[0018] The additional layer is preferably made of a dielectric material. Advantageously, the refractive index and thickness of at least one additional layer, as well as the thickness of the diamond layer, are selected such that reflections at the interface transition between the additional layer and the diamond layer are at least partially, and especially completely, compensated outward.

[0019] Other advantageous embodiments of the watch mirror and its components described below relate to both the watch mirror according to the first advantageous embodiment and the watch mirror according to the second advantageous embodiment, unless the first or second embodiment is explicitly referenced or it can be concluded from the description that only the first or only the second embodiment is possible.

[0020] The inside of the cover, especially the side of the cover facing the internal space of the watch (especially the internal space of the watch case) and / or at least one hand and / or at least one dial, when the crystal is installed in the watch. "Facing" means that the inside is closer to the internal space and / or the at least one hand and / or dial than the outside of the cover. The outside of the cover is away from the internal space and / or the at least one hand and / or dial.

[0021] The cover plate can preferably be made of diamond only.

[0022] When a watch crystal has both a layer constructed as a carrier and a layer constructed as a coating, it should be understood that the watch crystal has at least two layers besides the cover glass. Here, the coating is the first layer, the carrier is the second layer, and there is an intermediate layer, especially a laminated film or adhesive layer, between the first layer (coating) and the second layer (carrier).

[0023] The cover sheet preferably has a thickness of at least 0.1 mm, more preferably at least 0.3 mm, further preferably at least 0.5 mm, more preferably at least 0.75 mm, and more preferably at least 1 mm. The thickness of the cover sheet is preferably at most 3 mm. More preferably, the thickness of the cover sheet can be at most 2 mm, and particularly preferably at most 1.2 mm.

[0024] This allows for the optical advantages of the watch crystal. This will be explained below. When light rays pass through an optical medium with a higher optical density than air and parallel interfaces, obliquely incident light undergoes a certain deflection because it refracts towards the interface normal upon entering the optically dense medium and then bends again towards the interface normal upon exiting. The exiting light rays are parallel to the incident light rays, but with a certain deflection behind the cover glass. This deflection is proportional to the thickness of the optically dense medium, that is, proportional to the path length of the light rays traveling in the optically dense medium at different angles. Since the change in the direction of light rays in diamond media is the largest to date, the greater the thickness of the cover glass, the greater the deflection of the light rays. Although the reverse deflection of the light rays as they return through the diamond glass can compensate for this deflection, this alters the visible, captured area within the watch's internal space (especially the hand-dial space). Since it can be assumed that the person wearing a watch with the aforementioned crystal does not always view it perfectly perpendicularly through the crystal, a thinner cover glass, with its smaller deflection, is optically more aesthetically pleasing for viewing the internal space (especially the hand-dial space) than a thicker cover glass.

[0025] The cover plate is preferably made of synthetic diamond. However, it is also conceivable that the cover plate may be made of natural diamond. A cover plate made of synthetic diamond is superior to a cover plate made of natural diamond.

[0026] The aforementioned upper limit for cover plate thickness is particularly advantageous when the cover plate is made of synthetic diamond. This reduces the probability of optical defects (e.g., caused by foreign molecule intrusion or particulate contamination in the gas mixture) that may occur during the synthetic diamond manufacturing process (especially during crystallization). This also reduces the manufacturing cost of the cover plate.

[0027] The cover glass is preferably made of polycrystalline synthetic diamond or monocrystalline synthetic diamond. Cover glass made of polycrystalline synthetic diamond has the following advantages: it has no cleavage planes and is significantly more elastic. Therefore, the shatter resistance of thin-film polycrystalline synthetic diamond cover glass is significantly better than that of monocrystalline diamond glass. On the other hand, cover glass made of monocrystalline synthetic diamond has higher transparency than cover glass made of polycrystalline synthetic diamond. In addition, the growth rate of the monocrystalline substrate / seed crystal used to manufacture monocrystalline synthetic diamond cover glass is higher.

[0028] According to an advantageous variant of the watch crystal of the first advantageous embodiment, the watch crystal includes a layer configured as a carrier plate, which is fixedly connected to the cover plate. In particular, the carrier plate can have a thickness of at least 0.3 mm, preferably at least 0.5 mm, more preferably at least 1 mm, and more preferably at least 1.5 mm. The aforementioned upper limit of the cover plate thickness can also be considered in this embodiment of the invention. In particular, the carrier plate can be thicker than the cover plate. Furthermore, the carrier plate can be made of a different material than the cover plate. In other words, the carrier plate does not have to be made of diamond. In particular, the carrier plate can be made of glass, especially of a material with a coefficient of thermal expansion of 0.001 × 10⁻⁶. -6 K -1 Up to 2×10 -6 K -1 The support sheet is made of glass. Specifically, it can be made of quartz glass, Sitall glass, Vycor, Zerodur, CerVit, plastic, or sapphire glass. Thus, due to the similar coefficients of thermal expansion of the support sheet and the cover sheet, a stable connection between the cover sheet and the support sheet can be achieved with temperature changes. Quartz glass is particularly suitable for the support sheet because, in addition to a coefficient of thermal expansion similar to diamond, it possesses very interesting chemical and physical properties. The coefficient of thermal expansion is defined at room temperature, especially at 25 degrees Celsius. According to an advantageous embodiment, the support sheet can be made of glass, especially glass with a coefficient of thermal expansion of 0.5 × 10⁻⁶. -6 K -1 Up to 1.5×10 -6 K -1 Between, especially at 0.75×10 -6 K-1 Up to 1.25×10 -6 K -1 Between, preferred equal to 1×10 -6 K -1 It is made of glass.

[0029] Advantageously, the watch crystal includes a layer constructed as an intermediate layer (connecting intermediate layer) located between the cover glass and the carrier glass. This intermediate layer securely connects the cover glass and the carrier glass. This intermediate layer can, in particular, consist of one or more sublayers. These multiple sublayers can be made of the same or different materials. Manufacturing the watch crystal by placing an intermediate layer between the cover glass and the carrier glass, in other words, manufacturing the watch crystal as a laminated composite glass, allows for a particularly shatterproof watch crystal because, upon impact with the watch crystal, the impact energy can be absorbed by the carrier glass through the intermediate layer from the cover glass. Furthermore, laminating the cover glass and the carrier glass is an economical method because it significantly reduces the thickness of the expensive cover glass. In addition to the advantages of shatter resistance and economy, laminating the cover glass and the carrier glass has another advantage. The high refractive index of the cover glass causes a portion of the incident and re-emitted light to be lost due to reflection at the four transition points at the boundary between diamond and another optical medium. Because the refractive index difference between the two optical media (diamond-intermediate layer) at the interface between the cover glass and the interlayer is smaller than the refractive index difference between diamond and air, the optical balance of the laminated watch crystal is improved. In particular, it reduces haze that may occur in non-laminated watch crystals—depending on the color of the watch dial—making it less severe or completely non-interfering. In one embodiment of the invention, at least one coating on the inner side of the cover glass can be omitted in a laminated watch crystal. This simplifies the manufacturing process of the crystal. Another advantage of laminated watch crystals is that, because the interlayer and carrier layer have lower refractive indices compared to diamond (cover glass), the light deflection produced when light passes through the crystal is less than that produced when light passes through a non-laminated watch crystal, given the same total thickness.

[0030] In particular, the intermediate layer between the cover sheet and the carrier sheet can be thinner than the cover sheet and / or the carrier sheet.

[0031] However, the interlayer can also be thicker than the cover sheet. For example, the interlayer can have a thickness of 0.78 mm, while the cover sheet has a thickness of 0.5 mm or 0.3 mm. For this purpose, a laminated film with a thickness of, for example, 0.1 mm to 0.8 mm, particularly an EVA film, can be used. According to another example, the interlayer can have a thickness of 0.58 mm. To manufacture the interlayer, a first laminated film (particularly a first EVA film) with a thickness of, for example, 0.38 mm and a second laminated film (particularly a second EVA film) with a thickness of 0.2 mm can be used. Here, the cover sheet can be 0.5 mm thick, and therefore thinner than the interlayer.

[0032] In particular, the intermediate layer between the cover sheet and the carrier sheet may consist of at least one cured adhesive layer (preferably a cured UV adhesive) or at least one laminate containing / composed of EVA, PVB, Sentry glass or other laminated films.

[0033] In particular, the intermediate layer between the cover plate and the carrier plate may have a refractive index that differs from the refractive index of the carrier plate by at most + / -Δn = 0.4, preferably at most + / -Δn = 0.2. "Δn" represents the difference between the refractive index of the intermediate layer and the refractive index of the carrier plate. Preferably, the refractive index of the intermediate layer may be equal to the refractive index of the carrier plate.

[0034] In particular, the intermediate layer between the cover plate and the carrier plate can have a refractive index between 1.4 and 1.6, especially 1.48.

[0035] In particular, the intermediate layer between the cover plate and the carrier plate can have a thickness of at least 0.05 mm, preferably at least 0.1 mm. Furthermore, especially, the intermediate layer between the cover plate and the carrier plate can have a thickness of up to 0.8 mm, preferably up to 0.4 mm, individually or in total. In an advantageous variant of the watch crystal according to the first advantageous embodiment, the watch crystal can be constructed as a monolithic watch crystal, having only a cover plate and at least one layer on the cover plate (especially on the inner side of the cover plate) that is a coating. The monolithic watch crystal can also comprise two layers. In particular, the term "monolithic watch crystal" means that the watch crystal does not include a carrier plate.

[0036] According to an advantageous variant of the first advantageous embodiment, the watch crystal includes at least one layer configured as a coating. Advantageously, the coating is applied to the inside of the cover plate. For a watch crystal configured as a single-piece lens, the inside of the cover plate is advantageously the exposed inside, while for a double-piece lens, i.e., a watch crystal having a cover plate and a support plate, the inside is the laminated side. The laminated side is the side of the cover plate opposite to the outside, which, in the mounted state of the watch, faces the internal space of the watch (especially the internal space of the case) and / or at least one hand and / or dial.

[0037] According to an advantageous variant of the first advantageous embodiment, the watch crystal includes at least one layer configured as a coating. Advantageously, this coating is configured as a multi-layer coating, comprising multiple coating layers stacked upon each other, made of the same or different materials. Preferably, the coating layers have progressively lower refractive indices from the outside in. This progressively decreasing refractive index of the coating layers significantly reduces reflection losses that would occur at the transition between the cover glass and air in an uncoated watch crystal. The lower refractive index from the outside in particularly means that, in the mounted state of the watch crystal, the coating layer closer to the internal space of the watch (especially the internal space of the watch case) and / or at least one hand and / or dial has a lower refractive index than that other coating layer.

[0038] According to an advantageous variant of the watch crystal of the first advantageous embodiment, at least two, preferably all, layers (the layers here can be at least two of the following: a layer configured as a carrier, at least one layer configured as a coating, and a layer configured as an intermediate layer) have progressively lower refractive indices from the outside to the inside. However, this decrease in refractive index may not apply to the transition from the intermediate layer (laminated or adhesive layer) to the carrier. The latter may have a higher refractive index than the intermediate layer due to material properties. The lower refractive index from the outside to the inside here specifically means that, in the mounted state of the watch crystal, the layer closer to the internal space of the watch (especially the internal space of the watch case) and / or at least one watch hand and / or dial has a lower refractive index than the other layer. This applies particularly to all layers. However, it should be noted here that "all layers" refers to those layers with a thickness significantly greater than the wavelength of visible light, preferably greater than 2 μm. Therefore, by the progressively decreasing refractive index of each layer, the reflection loss that would occur at the transition between the cover plate and air in an uncoated watch crystal can be significantly reduced.

[0039] According to an advantageous variant of the watch lens of the first advantageous embodiment, the refractive index of the inner side of the cover can be reduced to at least 1.8, preferably at least 1.5, by at least one, preferably at least two, and more preferably at least three layers.

[0040] According to an advantageous variant of the watch lens of the first advantageous embodiment, the watch lens may include at least one layer configured as an antireflective coating. In particular, the antireflective coating may be applied to one or more layers with a refractive index reduced to at least 1.8, preferably at least 1.5. Specifically, each layer configured as an antireflective coating, i.e., each antireflective coating, is matched to its respective adjacent medium. The antireflective coating is advantageously mounted on the inner side of the cover plate and / or the inner side of the intermediate layer between the cover plate and the carrier plate and / or the inner side of the carrier plate. The antireflective coating reduces reflection loss when light exits from the respective media to which the antireflective coating is applied, thereby improving light output. It should be noted that the different coefficients of thermal expansion of different materials do not play a significant role in the antireflective coating because these coatings are very thin (e.g., 0.5 μm or 0.2 μm) and therefore elastic, and the watch lens does not need to consider very large temperature fluctuations.

[0041] The optical performance of a watch crystal can be improved by incorporating one or more layers configured as anti-reflective coatings. However, it is also possible, especially in laminated watch crystals, to omit the anti-reflective coating when the cover glass is connected to the carrier glass via an intermediate layer, since the optical performance of the watch crystal can be improved by the optical properties of the intermediate layer.

[0042] In particular, the aforementioned gradual reduction of the refractive index can be achieved in the following ways:

[0043] • The cover sheet and the carrier sheet are laminated together, eliminating the need for additional coatings.

[0044] • Multiple coatings are applied to the inside of a non-laminated monolithic lens (a cover glass without a support plate), resulting in progressively decreasing refractive indices.

[0045] • In the case of multi-piece watch crystals (safety glass), a single-layer coating is applied to the laminated side of the cover glass.

[0046] • In the case of multi-piece watch crystals (safety glass), multiple coatings are applied to the laminated side of the cover glass.

[0047] • In the case of multi-piece crystals (safety glass), multiple coatings are applied to the laminated side of the cover glass, and an additional single coating is applied to the inner side of the carrier plate (towards the internal space of the watch (especially the internal space of the watch case) and / or the carrier plate side of at least one watch hand and / or at least one dial).

[0048] • In the case of multi-piece crystals (safety glass), a single-layer coating is applied to the laminated side of the cover glass, and an additional single-layer coating is applied to the inside of the carrier plate (towards the internal space of the watch (especially the internal space of the watch case) and / or the carrier plate side of at least one watch hand and / or at least one dial).

[0049] • Combine a single or multiple coatings on one of the aforementioned mirror surfaces to gradually reduce the refractive index difference, and combine a single or multiple anti-reflective coatings.

[0050] By applying multiple coatings to the inside of the cover glass of the watch crystal (as a single or multiple watch crystals), a total light output of 67.5% can be achieved.

[0051] Within the scope of this invention, multi-element watch crystals preferably refer to at least two-element watch crystals.

[0052] In particular, multi-element crystals can be configured with:

[0053] • Single-layer coating on the inside of the carrier sheet (no coating on the inside of the cover sheet)

[0054] • Multiple coatings on the inside of the carrier sheet (no coating on the inside of the cover sheet)

[0055] • Single-layer coating on the inside of the cover plate (no coating on the inside of the carrier plate)

[0056] • Single-layer coating on the inside of the cover plate and single-layer coating on the inside of the carrier plate

[0057] • Single-layer coating on the inside of the cover plate and multiple coatings on the inside of the carrier plate

[0058] • Multiple coatings on the inside of the cover plate (no coating on the inside of the carrier plate)

[0059] • Multiple coatings on the inside of the cover plate and a single coating on the inside of the carrier plate

[0060] • Multiple coatings on the inside of the cover plate and multiple coatings on the inside of the carrier plate

[0061] Advantageously, the cover glass can be a diamond sheet with a type IIa crystal structure (lattice structure). In other words, the cover glass can be type IIa diamond. Type IIa is the purest carbon lattice type of diamond, meaning it has the fewest inclusions. In particular, a certain amount of nitrogen inclusions largely determines the color of the diamond. Therefore, type IIa diamond is the purest and most colorless diamond. Thus, a cover glass made of type IIa diamond has the advantage that light can pass through the cover glass with the least interference, whereas cover glasses of other diamond types may constitute color filters. Coloring (usually a yellow tint) can negatively affect the vibrancy of the color (e.g., the background color of the pointer) and cause light loss. In particular, a watch lens made of a cover glass made of type IIa single-crystal synthetic diamond is a particularly preferred embodiment.

[0062] Diamond possesses specific cleavage planes in which the unit cells can be relatively easily separated from each other. Referring to the fact that diamond is, in principle, a face-centered cubic lattice (a "cell" with a calculated 8 carbon atoms), there exist certain planes typically described by the three Miller indices. The relevant structural planes in the diamond lattice are primarily three cubic faces, which can be represented by the Miller indices (100), (010), and (001).

[0063] Although diamond has a cubic basic structure, it appears as an octahedron in its natural crystalline form. Here, the cubic planes (100), (010) and (001) can be identified as those planes in the octahedron that connect four of its six vertices that lie on the same plane.

[0064] An octahedron has three possible planes, each connecting its four vertices. In cubic coordinates, these planes can be represented by Miller indices (100), (010), and (001). From a crystallographic perspective, these three planes are equivalent because the cube or octahedron representing the diamond crystal structure can be rotated in any direction, and the exact same diamond lattice atomic structure is mapped in every direction in which the cube or octahedron face is directly observed.

[0065] The second type of crystal plane in a diamond cubic lattice is those faces that represent three of the six possible diagonal faces of the cube, which connect four of the eight vertices of the cube and each contain a coordinate vector in the cube coordinate system representation. These planes can be represented by Miller indices (110), (101), and (011).

[0066] The prominent crystal planes (110), (101), and (011) in the octahedron are those planes that extend parallel to an octahedron face, contain two vertices of the octahedron, and pass through the four triangular octahedron faces as angle bisectors. Here, the three crystal planes (110), (101), and (011) are also equivalent from the top view of the atomic lattice.

[0067] The third significant crystal plane that plays an important role in diamond is the plane that can be represented by the Miller index (111) in the cubic representation of the diamond lattice. This lattice plane (111) is represented as an octahedral face in an octahedron. Here, all four possible octahedral planes (there are four such planes in total, since every two octahedral faces are parallel to each other) are also equivalent from a schematic top view of the atomic lattice.

[0068] In a diamond lattice that can be represented as a plane using coordinate vectors, there exist three basic planes of diamond, which are represented in an octahedron as follows:

[0069] • The plane connecting the four vertices: (100), (001), (010) (referred to as the 4-point plane in the diamond polishing industry)

[0070] • Or the plane connecting the four angle bisectors: (110), (101), (011) (referred to as the 2-point plane in the diamond polishing industry)

[0071] • Or a plane extending parallel to the surface of the octahedron: (111) (referred to as the 3-point plane in the diamond polishing industry)

[0072] (111) The plane, which is a plane extending parallel to one of the four possible octahedral faces (each pair of octahedral faces is parallel to each other), is the cleavage plane along which single-crystal diamond can be very easily split, i.e., very easily split under the corresponding compressive load.

[0073] With this in mind, according to an advantageous embodiment, the cover plate can be made of single-crystal synthetic diamond, wherein the surface of the cover plate extends parallel to one of the crystallographic planes (100), (010), or (001), or parallel to one of the crystallographic planes (110), (101), or (011). Thus, the surface of the cover plate forms an angle with the crystallographic plane (111), and also with the other three crystallographically equivalent planes of the octahedral face. The surface of the cover plate is particularly the outward or inward facing surface; in other words, the surface facing or away from the internal space of the watch (particularly the internal space of the watch case) and / or at least one hand and / or dial. Therefore, the surface of the cover plate does not extend perpendicular to the cleavage plane (111), thereby preventing the cover plate from breaking along the cleavage plane due to impact with the crystal. Furthermore, the surface does not extend parallel to the cleavage plane (111). Therefore, parallel cleavage can be avoided when the crystal bends under pressure loads. When the crystal bends, the bent crystal forms a radius of curvature. At this point, the radius of curvature of the crystal surface facing the dial and / or the internal space of the watch (especially the internal space of the watch case) and / or at least one hand direction will be greater than the radius of curvature of the crystal surface facing away from the watch. The two different radii of curvature of the bent crystal may cause the diamond layers to peel off along the cleavage plane (111) (if the cleavage plane is parallel to the diamond glass surface and therefore extends at a 90° angle to the radius of curvature), because huge tensile stresses may occur between the diamond layers, and these tensile stresses are generated precisely along the cleavage plane. With this crystal construction, particularly shatterproof cover plates and therefore particularly shatterproof crystals can be manufactured, because on the one hand, the danger of cleavage along parallel cleavage planes is eliminated, and on the other hand, the bending of the crystal is made more difficult by a stronger cover plate, thus reducing the bending.

[0074] According to an advantageous embodiment, the cover glass can be made of polycrystalline diamond. Preferably, the polycrystalline diamond can have nanocrystalline diamond cells (especially between 5 nm and 100 nm) or microcrystalline diamond cells (especially larger than 100 nm, preferably larger than 20 μm). This configuration is more advantageous when the number of individual polycrystalline diamond cells is larger. This is because the greater the number and the smaller the size of individual diamond cells, the greater the optical damage to the mirror, especially so-called haze, which is caused by light scattering due to the structural transformation of individual diamond cells. By increasing the number of diamond cells and thus reducing their number, the optical damage / haze caused by the diamond cells of polycrystalline diamond is reduced. In particular, optical damage is minimized in polycrystalline diamond with microcrystalline diamond cells because it has the largest and therefore the fewest number of individual cells. The optical quality of polycrystalline diamond (especially polycrystalline diamond with microcrystalline diamond cells) improves particularly with increasing duration of the polycrystalline diamond growth process, as individual diamond cells increase in size with continuous growth and gradually displace their smaller neighboring cells. Therefore, as the growth time increases and the size of a diamond unit cell increases, the total number of existing unit cells decreases.

[0075] When using polycrystalline synthetic diamond as a cover plate, it is preferable that the nucleation side forms the inner side of the cover plate and the growth side forms the outer side. In other words, the inner side of the cover plate is formed by the nucleation side of the grown diamond, and the outer side is formed by the growth side of the grown diamond. The inner side is the side of the cover plate facing the internal space of the watch (especially the internal space of the watch case) and / or at least one hand and / or dial, while the outer side is the side of the cover plate facing away from the internal space of the watch (especially the internal space of the watch case) and / or the at least one hand and / or dial. Because the nucleation side has far more and much smaller diamond cells than the growth side, it is more flexible / more resilient. Therefore, when the crystal is subjected to compressive loads, the inner side can bend more easily and better withstand the tensile stress that occurs on the inner side. The compressive stress that occurs on the outer side of the cover plate when the crystal is subjected to compressive loads does not pose a significant problem for the cover plate because diamond is very hard and pressure-resistant. With the above-described construction of the cover plate, a particularly shatterproof polycrystalline synthetic diamond can be manufactured, thereby creating a particularly shatterproof cover plate.

[0076] A watch crystal (particularly for wristwatches) includes a cover plate made of diamond and a layer constructed as a support plate (the refractive index of the layer is lower than that of the cover plate and the thickness is greater than the wavelength of visible light), wherein the cover plate is a single-crystal synthetic diamond, and the surface of the cover plate extends parallel to one of the crystallographic planes (100), (010) or (001) or parallel to one of the crystallographic planes (110), (101), (011), and in particular, wherein the support plate has a diameter of 0.001 × 10⁻⁶. -6 K -1 Up to 2×10 -6 K -1Between, preferably 0.5×10 -6 K -1 Up to 1.5×10 -6 K -1 Between, further optimization of 0.75×10 -6 K -1 Up to 1.25×10 -6 K -1 Between, preferred equal to 1×10 -6 K -1 The coefficient of thermal expansion is particularly advantageous because it provides good optical quality and high shatter resistance. The coefficient of thermal expansion is defined here at room temperature, especially at 25 degrees Celsius.

[0077] Similar advantages also apply to a watch crystal (especially for wristwatches) comprising a cover plate made of diamond and a layer constructed as a support layer (the refractive index of this layer is lower than that of the cover plate and its thickness is greater than the wavelength of visible light), wherein when polycrystalline synthetic diamond is used as the cover plate, the nucleation side forms the inner side of the cover plate and the growth side forms the outer side of the cover plate, and the thickness of the cover plate is less than or equal to 1.2 mm, especially wherein the support layer has a thickness of 0.001 × 10⁻⁶ mm. -6 K -1 Up to 2×10 -6 K -1 Between, preferably 0.5×10 -6 K -1 Up to 1.5×10 -6 K -1 Between, further optimization of 0.75×10 -6 K -1 Up to 1.25×10 -6 K -1 Between, preferred equal to 1×10 -6 K -1 The coefficient of thermal expansion. The coefficient of thermal expansion is defined here at room temperature, especially at 25 degrees Celsius.

[0078] Advantageously, the watch crystal may have at least one decorative element, particularly a gemstone, arranged in a groove formed in the support plate. Preferably, the watch crystal has multiple decorative elements (especially gemstones) and multiple grooves. One decorative element is arranged in each groove. The number of grooves corresponds to the number of decorative elements. Within the scope of the invention, the term "gemstone" advantageously refers to a stone, especially a faceted (i.e., non-rough) semi-precious or precious stone. The gemstone can be, in particular, diamond.

[0079] The upper region of the decorative element is preferably in direct contact with the connecting intermediate layer. Preferably, the groove region below the contact area between the decorative element and the groove wall contains only air or a vacuum. In the case of a decorative element constructed as a gemstone, the upper region preferably includes the table and / or crown facets of the gemstone. Correspondingly, in the case of a decorative element constructed as a gemstone, the lower region of the decorative element includes the pavilion facets and / or preferably the tapered region of the gemstone.

[0080] The present invention also relates to a method for manufacturing watch crystals (especially the aforementioned watch crystals).

[0081] According to a first advantageous embodiment, the method includes the steps of: providing a substrate located on a reference plane; growing a synthetic diamond blank on the substrate along a growth direction perpendicular to the reference plane; and cutting and / or grinding the diamond blank to manufacture a cover plate. Furthermore, the method includes attaching the cover plate to a layer configured as a carrier sheet (the refractive index of which is lower than that of the cover plate), and / or attaching the cover plate to at least one layer configured as a coating (the refractive index of which is lower than that of the cover plate). The layer configured as a carrier sheet preferably has a thickness greater than the visible light wavelength, preferably greater than 2 μm. The layer configured as a coating preferably has a thickness greater than the visible light wavelength, preferably greater than 2 μm.

[0082] Preferably, the method according to the first advantageous embodiment may include the step of attaching the outer side of the cover plate to a double layer having a diamond layer and an additional layer located between the cover plate and the diamond layer. The additional layer has a lower refractive index than the cover plate and the diamond layer.

[0083] According to a second advantageous embodiment, the method includes: providing a substrate located on a reference plane; growing a synthetic diamond blank on the substrate along a growth direction perpendicular to the reference plane (particularly by microwave plasma chemical vapor deposition (MPCVD) or hot-wire CVD (HFCVD); cutting and / or grinding the diamond blank to manufacture a capping sheet; and attaching the outer side of the capping sheet to a bilayer having a diamond layer and an additional layer located between the capping sheet and the diamond layer. The additional layer has a refractive index lower than that of the capping sheet and the diamond layer. The MPCVD method can also be referred to as microwave plasma chemical vapor deposition. The HFCVD method can also be referred to as hot-wire CVD or hot-wire activated chemical vapor deposition.

[0084] The following additional advantageous embodiments of the method described below relate to both the method according to the first advantageous embodiment and the method according to the second advantageous embodiment.

[0085] The cultivation of the aforementioned synthetic diamond blanks can be carried out, in particular, by microwave plasma chemical vapor deposition (MPCVD) or hot filament CVD (HFCVD).

[0086] The method may also preferably include the following steps: when using a substrate configured for heteroepitaxial growth, or when using a substrate configured for homoepitaxial growth (wherein the substrate itself is composed of diamond, preferably of a polycrystalline fragmented diamond layer), separating the diamond blank from the substrate by cutting and / or grinding.

[0087] The method may also preferably include a step of cutting the diamond blank perpendicular to the growth direction.

[0088] The method may also preferably include the following steps: cutting the diamond blank perpendicular to the growth direction into at least a plurality of usable caps, or cutting it into at least one usable cap and at least one usable substrate.

[0089] The method may also preferably include a step of grinding the diamond blank in a plane perpendicular to the growth direction.

[0090] Advantageously, the diamond blank can be grown along the growth direction at a growth rate of less than 15 μm per hour, preferably less than 8 μm per hour, and more preferably less than 5 μm per hour. This allows for good purity and optical transparency in the grown diamond and therefore the cover plate. At a growth rate of less than 5 μm per hour, particularly high uniformity and optical purity of the grown diamond can be achieved. Here, the growth rate specifically refers to the rate at which carbon atoms are deposited on the substrate during the MPCVD method. The growth rate can be accelerated or slowed down by various factors. In particular, the negative pressure in the vacuum chamber containing the plasma sphere, the frequency of the microwave generator, the temperature in the plasma sphere, the precise height of the substrate plane, i.e., the "growth plane," the ratio of possibly added accelerating gases such as nitrogen, argon, oxygen, hydrogen, and methane, and other factors can affect the growth rate of the grown diamond.

[0091] Advantageously, a substrate configured for heteroepitaxial growth can be used. This offers the following advantages: once the desired thickness is reached, the substrate with the diamond layer can be simply removed from the equipment and ground to obtain the cover plate. This allows for the rapid fabrication of monolithic watch mirrors, for example. Furthermore, it eliminates the need for expensive substrates, allows for lossless separation of multiple wafers, carries virtually no risk of defect accumulation during growth, and eliminates the need for laser cutting and the provision of laser cutting machines for separating the individual wafers. Therefore, fabricating watch mirrors via heteroepitaxial growth represents a very economical method.

[0092] Advantageously, according to the first alternative, a substrate with a large number of diamond particles can be used for homoepitaxial growth. Advantageously, according to the second alternative, single-crystal diamond can also be used as the substrate.

[0093] The diamond blank is preferably subjected to high pressure and / or high temperature post-treatment after growth to improve its color and / or final crystal structure. This allows for improved color and / or improved final crystal structure in the cover glass and thus the crystal. Furthermore, it enables mass-produced cover glass to have the same or very similar color and / or final crystal structure. This is because the synthetic diamonds produced during the growth of single-crystal and polycrystalline diamond layers may differ in color and may exhibit irregularities in the diamond lattice. Under high pressure and / or high temperature, the diamond blank is subjected to conditions typically found at a depth of approximately 110 km below the Earth's surface, similar to diamond crystallization. This process allows nitrogen to escape from the diamond and may allow incompletely crystalline sites to fully crystallize. Here, high pressure is preferably understood as a pressure between 45,000 atm and 60,000 atm. High temperature is preferably understood as a temperature between 1250°C and 1700°C.

[0094] Furthermore, the present invention relates to methods according to embodiments 1 and 2, which can be used to manufacture watch crystals, particularly one of the aforementioned watch crystals. Embodiment 1 illustrates a method for manufacturing a diamond layer directly on a carrier plate, preferably used when a cover plate is directly disposed on the carrier plate; this specifically means that the aforementioned layer is absent between the carrier plate and the cover plate, particularly the absence of an intermediate layer (laminated layer) and coating, as well as an anti-reflective coating. Embodiment 2 illustrates a method for manufacturing a diamond sheet, which can be used in all of the aforementioned watch crystal options.

[0095] Therefore, the present invention provides a method for manufacturing a watch crystal (Variation 1), comprising at least the following steps:

[0096] (i) A support sheet made of glass (especially quartz glass) that is transparent to visible light is provided, having a metal film on its upper side. This metal film may be described as having catalytic properties. Therefore, the support sheet is primarily composed of silicon dioxide, wherein other materials may be mixed in, for example, to change the coefficient of thermal expansion—this will be described in detail later. Preferably, the method further includes applying the metal film to the upper side of the support sheet. The metal film may be deposited in a crystalline manner and / or deposited and recrystallized in an amorphous manner, particularly by an annealing process. The annealing method will be further described later in the section concerning copper and nickel.

[0097] (ii) Furthermore, in this method, a diamond layer serving as a cover plate is grown on the upper side of the support sheet by chemical vapor deposition (also known as CVD or chemical vapor deposition method). Microwave plasma chemical vapor deposition (MPCVD) or hot-wire CVD (HFCVD) is particularly employed here. This method step is carried out, especially, in an apparatus used to perform chemical vapor deposition.

[0098] Therefore, the watch crystal includes a carrier plate and a diamond layer fixedly connected thereto.

[0099] This invention presents an ideal solution for transparent, scratch-resistant watch crystals, namely a direct combination of a carrier sheet (whose coefficient of expansion is compatible with that of diamond) and a synthetic diamond layer deposited directly on it via CVD as a cover sheet.

[0100] Within the scope of this invention, it is recognized that polycrystalline diamond layers, typically based on DND (detonation nanodiamond) initiation methods, suffer from the following drawbacks: extremely high optical scattering exists on the nucleation side (i.e., the location where the initially randomly dispersed, very small (5 nm to 40 nm) diamond grains in the diamond layer initiate the growth process). At an average size of 20 nm, 2.5 billion diamond particles can be accommodated per square millimeter. When these layers, composed of individual crystals, begin to grow in various directions using CVD methods, a highly fragmented "nucleation layer" is initially formed, which is therefore not optically completely transparent. As the diamond layer continues to grow, the number of nucleation cells decreases because diamond crystals growing perpendicular to the support sheet along the strong growth direction overtake and displace their adjacent cells. Therefore, the situation improves with increasing layer thickness. The bottom layer, i.e., the nucleation side, needs to be ground away to obtain an optically satisfactory product. However, when such a polycrystalline layer is grown directly on the final substrate (the carrier sheet according to the invention), the nucleation layer cannot be removed because it grows directly on the carrier sheet that should be retained as part of the structure.

[0101] Within the scope of this invention, it is recognized that a metal thin film on the upper side of the substrate allows for the growth of an optically completely transparent diamond layer as a cover plate. A more detailed discussion follows using a nickel metal thin film as an example; however, these considerations also apply to copper metal thin films.

[0102] For diamond to grow in a CVD process, a nucleation core, known as a "seed crystal," is first required that is similar to or identical to the diamond lattice. Typically, these nucleation cores are diamond themselves. Diamond will not grow on pure quartz glass in a CVD process. Therefore, it is preferable to impregnate the metal film with diamond powder and / or diamond-like nucleation cells.

[0103] Diamond has a face-centered cubic (FCC) crystal lattice. Other materials also have such lattices, such as silicon or certain metals like nickel and copper. However, for such materials to have a positive influence on the growth of diamond films, the cell size of the FCC lattice must roughly correspond to that of diamond, not only in structure but also in size. For example, the cell size of silicon is 5.43 Å, while that of diamond is 3.57 Å.

[0104] Since both nickel and silicon have cubic lattices, some nickel-silicon compounds also have cubic lattices. The cell size of Ni3Si is also very similar to that of diamond (3.506 Å).

[0105] To grow synthetic diamond on non-diamond substrates, very fine diamond powder is typically used, in which the original crystal structure of the diamond is preserved. DND (detonation nanodiamond) powder with a particle size of approximately 5-40 nm is commonly used, produced during the explosion of a TNT / RDX mixture in a sealed pressure chamber. However, other methods exist for manufacturing crystalline diamond powder. Methods for manufacturing diamond powder by grinding synthetic or natural diamond are less suitable as nucleation cells because this primarily produces fragments rather than complete diamond crystals. The fine diamond powder is then coated onto a substrate that has been thoroughly cleaned with acetone and various alcohols beforehand using a suitable solvent. Various methods exist for this, such as using ultra-fine 3D printing equipment and equipment used in the semiconductor industry to apply photolithographic layers to wafers. After impregnation, the substrate is placed in a CVD reactor. In plasma methods, diamond crystals grow according to their typical lattice structure by depositing carbon from methane gas. However, this method for manufacturing transparent components will not produce useful results without modification, as the optical quality cannot meet requirements such as high-quality watch mirrors. High light scattering in a quartz glass substrate grown from polycrystalline synthetic diamond would result in such severe haze in the diamond layer that the product would be unsuitable for use as a watch mirror.

[0106] The present invention now proposes an improvement to this process, namely, embedding at least one thin film between the carrier sheet and the diamond layer serving as a cover sheet, which transforms the completely disordered polycrystalline properties of the diamond growth layer into an ordered system with growth direction orientation, which can ultimately be referred to as single-crystal or "quasi-single-crystal", while also bridging the problem of different expansion coefficients of diamond and quartz glass, and optically disappearing or becoming invisible again after completing its task.

[0107] For example, nickel—and copper—performs exceptionally well among all the materials that could be used for this purpose, for the following reasons: (1) Nickel, copper and iridium also have face-centered cubic lattice structures, just like silicon and diamond.

[0108] (2) The unit cell, or the size of the basic atomic cell, varies with nickel and copper by only slightly more than 1% with diamond. The unit cell size of nickel is 3.52 Å, that of diamond is 3.57 Å, and that of copper is 3.615 Å. Thus, based on surface tension, during the impregnation process (application of diamond powder), diamond crystals are deposited on the nickel or copper layer in a more dense and ordered manner. Advantageously, the nickel or copper film is already deposited on the substrate in an ordered manner with the correct orientation.

[0109] When nickel and copper layers are deposited as thin films on substrates whose structures do not conform to those of pure nickel or pure copper, these layers tend to be structured during the subsequent annealing process. Here, various types of structures emerge depending on the temperature, annealing duration, and the substrate on which the deposited layers are located. Face-centered cubic cells arranged in an ordered orientation are the ideal structure for subsequent growth of single-crystal diamond. However, fibrous structures can also occur, where individual cell groups reach a size 500 times that of a single cell. Such structures are unsuitable for our application.

[0110] Besides the annealing process, there are other methods to promote the formation of face-centered cubic structures in copper or nickel films with ordered orientation, such as ion bombardment and the BEN method (bias-enhanced nucleation).

[0111] Therefore, the first step is to deposit a thin metal film (especially nickel or copper) by sputtering, electron beam, vapor deposition or other suitable methods.

[0112] The second step is advantageously an annealing process, i.e., heating under a protective gas (such as argon) (usually under negative pressure), or other processes suitable for the crystallographic structuring of metal layers.

[0113] In particular, these two steps can also be combined into one, namely, depositing a metal thin film at a sufficiently high substrate temperature.

[0114] The ordered crystal structure of the metal film is a preferred prerequisite for the orientation of the diamond growth direction (e.g., preferably in the (110) direction) when "seeding" diamond crystals, which may correspond, for example, to the (220) or (110) orientation of nickel.

[0115] Diamond not only possesses the highest hardness value but also an extremely high surface energy. This high surface energy gives the material a strong tendency to attract other molecules. Furthermore, the surface energy varies depending on the crystallographic orientation of the diamond lattice surface.

[0116] The different surface energies of facets with different orientations result in different values ​​of diamond cohesion within the material. Nickel also has a high surface energy value. This value for nickel also varies depending on the crystallographic orientation in the face-centered cubic lattice.

[0117] When diamond nanocrystals are applied to a crystallographically oriented nickel substrate (metal film) in the correct manner, the diamond nanocrystals are arranged in such a way that certain orientation faces of the diamond crystals match the corresponding orientation faces of the cubic nickel structure.

[0118] Nickel is a metal that, during diamond growth in a CVD chamber, bonds with a substrate (quartz glass) beneath the nickel layer under the influence of plasma above the nickel layer and temperatures ranging from 700°C to 1150°C (preferably 900°C to 1000°C). This means that at high temperatures, nickel diffuses into the substrate and partially replaces silicon atoms there, partially forming NiSi or NiSi2 compounds, which are ultimately absorbed and dissolved by the quartz glass.

[0119] This absorption by the nickel layer has several advantages. Firstly, the nickel layer disappears, thus avoiding optical interference. Although a very thin nickel layer is almost invisible to the naked eye, the opacity of the nickel still contributes to an additional enhancement of component haze. Secondly, nickel atoms diffuse into the quartz glass, forming a "nickel glass" at the boundary between the quartz glass and the diamond layer. In this layer, the coefficient of thermal expansion is no longer the 0.45 × 10⁻⁶ of pure quartz glass. -6 K -1 It is not, but slightly higher.

[0120] Directly coating quartz glass (or other glass) not only poses a risk of stress cracking due to differences in the coefficients of thermal expansion at room temperature, but also, especially, during cooling from the operating temperature of the CVD method (approximately 950°C). Diamond has a coefficient of thermal expansion of 4 × 10⁻⁶ at 1000°C. -6 K -1 The coefficient of thermal expansion at room temperature (especially 25°C) is 1×10⁻⁶. -6 K -1 The coefficient of thermal expansion of quartz glass remains almost constant at different temperatures.

[0121] This means that under normal circumstances, the diamond layer will peel off from the quartz glass as it cools after the CVD process. Even if the stress between the diamond layer and the quartz glass does not directly cause the diamond layer to peel off after the CVD process, the risk of glass breakage is by no means eliminated.

[0122] The reason lies in the extreme sensitivity of glass and quartz glass to microcracks. At some point, a microscopic microcrack may form in a stress area. If the environment surrounding the crack is under stress, the crack will grow over time, eventually connecting with adjacent cracks, and leading to the peeling off of the diamond layer over a long period (possibly even years later).

[0123] Based on the above considerations and various experiments, the following features of this method have proven to be advantageous:

[0124] Preferably, the metal film comprises nickel and / or copper. Preferably, more than half, and especially all, of the metal film is composed of at least one of these metals. Alloys of these two metals (especially copper and nickel) have also proven advantageous for the metal film.

[0125] Nickel and copper are more suitable for use in thin metal films for the following reasons:

[0126] 1) The cell edge lengths of nickel and copper differ very little from those of diamond, especially less than 2.5%. Since diamond powder should align with the lattice of the oriented metal film through its surface tension, the results indicate that it should have unit cells of approximately the same size. Copper and nickel satisfy this condition.

[0127] 2) The transparency of the coated substrate depends largely on the diffusion of the metal film into the glass (quartz glass). The diffusion of the metal layer into quartz glass is a process in which the metal is oxidized due to silicon-oxygen bonding (SiO2 in quartz glass). Thus, for example, nickel abstracts one or two oxygen atoms from the glass and deposits into the quartz glass through an oxidation process, or replaces one of the silicon atoms in the long Si-O2 chain, or is squeezed into it. Nickel or copper oxidizes better than platinum or iridium, and therefore they also diffuse into quartz glass better because the bonding between Si and O2 is stronger than that between platinum and oxygen or iridium and oxygen.

[0128] In addition to experiments, the following considerations also played a role in the selection of metals:

[0129] Diamond: unit cell size 3.57 angstroms;

[0130] Nickel: cell size 3.52 Å, differing from diamond by 0.05 Å; melting point: 1455°C.

[0131] Copper: cell size 3.615 Å, differing from diamond by 0.045 Å; melting point: 1083°C.

[0132] Iridium: cell size 3.833 Å, differing from diamond by 0.26 Å; melting point: 2446°C.

[0133] The high melting point of iridium makes it difficult to anneal thin iridium films on quartz glass surfaces in the same way as copper or nickel, because quartz glass has a significantly lower melting point.

[0134] Iridium is not truly superior to diamond in terms of cell size (3.833 Å).

[0135] Nickel and copper metal films are particularly suitable for growth on quartz glass because the cell size of the face-centered cubic crystal structure is very similar to that of diamond.

[0136] Copper-nickel alloys are also preferred for use as metal thin films; in particular, their cubic cell size deviates from that of diamond cubic cells by only 0.025 angstroms.

[0137] Pure copper is particularly preferred because the metal film should diffuse into the quartz glass and thus dissolve after the diamond first crystallizes, as it has the highest diffusion coefficient in quartz glass among the aforementioned materials.

[0138] Preferably, the thickness of the metal film before diamond cultivation is at most 30 nm, more preferably at most 20 nm, and even more preferably at most 10 nm; preferably, the thickness of the metal film is at least 2 nm. During cultivation, the metal film can partially or completely diffuse into the carrier sheet, thus disappearing optically.

[0139] Preferably, the thickness of the metal film before diamond cultivation is between 5 nm and 20 nm, more preferably between 5 nm and 10 nm, and especially 5 nm. Thin metal films exhibit better orientation during annealing than thick metal films, and furthermore, they diffuse away more rapidly than thick metal films. Due to their low thickness, the metal film can diffuse substantially completely or completely into the carrier. "Substantially completely" particularly means diffusion into at least 80%, preferably at least 90%, and less than 100%—the latter, of course, refers to complete diffusion. The metal film disappears as it diffuses into the carrier.

[0140] Preferably, the diamond layer used as a cover sheet has a thickness of at least 30 μm and / or a maximum of 2 mm after cultivation.

[0141] Particularly preferred is that the thickness of the diamond layer as a cover sheet after cultivation is at least 10 μm and / or at most 0.5 mm.

[0142] Preferably, the coefficient of thermal expansion of the bearing plate is specified to be 0.45 × 10⁻⁶. -6 K -1 Up to 1.2×10 -6 K -1 The preferred value is 0.8×10 - 6 K -1 Up to 1.2×10 -6 K -1 .

[0143] For different coefficients of expansion, a certain buffer between the two layers or at least modification of the quartz glass is advantageous.

[0144] Nowadays, many parameters of glass can be altered by adding substances to it, especially the coefficient of thermal expansion, softening temperature, and melting point.

[0145] Quartz is the basic material of glass. In many glass varieties, some silicon atoms are usually replaced with atoms of one or more other elements. For example, high-quality lead crystal glass can contain up to 75% lead oxide, and high-quality silver crystal glass can contain up to 50% silver oxide. Glass can absorb many metals by replacing silicon atoms with foreign atoms. In this case, the coefficient of thermal expansion changes, and in most cases increases. Therefore, the coefficient of thermal expansion of most glass varieties is around 6 × 10⁻⁶. - 6 K -1 Up to 9×10 -6 K -1 Between 12 and 20 times the coefficient of thermal expansion of quartz glass.

[0146] To address the problem of the extremely different temperature-dependent coefficients of thermal expansion of diamond at different temperatures, various methods exist:

[0147] The carrier glass (i.e., the support glass) can be adjusted to have a significantly higher coefficient of thermal expansion at higher temperatures, while maintaining the same coefficient of thermal expansion as diamond at room temperature. This results in the carrier glass exhibiting a temperature-dependent expansion curve similar to diamond, preventing stress during cooling after the CVD process.

[0148] Another method is a carrier sheet (i.e., a carrier glass) that also (like diamond) has 4×10⁻⁶ ohms at 1000°C. -6 K -1 It has a coefficient of thermal expansion, but crystallizes in a very specific way upon cooling, making it similar to quartz glass in terms of coefficient of thermal expansion at room temperature, and therefore also similar to diamond. In particular, the support sheet can be made of a glass that:

[0149] • Has a softening temperature between 500°C and 650°C, especially 550°C, and / or

[0150] • It has a temperature-dependent variable expansion coefficient, which is 3.9 × 10⁻⁶ at 900°C to 1100°C, especially at 1000°C. -6 K -1 Up to 4.1×10 -6 K -1 Especially for 4×10 -6 K -1 The value is 0.9 × 10⁻⁶ at temperatures ranging from 0°C to 100°C, especially at 25°C. -6 K -1 Up to 1.1×10 -6 K -1 Especially for 1×10 -6 K -1 , and / or

[0151] • It has a chemical composition that causes 3.9 × 10⁻⁶ ppm at 900°C to 1100°C, especially at 1000°C. -6 K -1 Up to 4.1×10 -6 K -1 Especially for 4×10 -6 K -1 The coefficient of thermal expansion is 0.9 × 10⁻⁶, and it undergoes a crystallization process when cooled from the operating temperature of the CVD process, resulting in a coefficient of thermal expansion of 0.9 × 10⁻⁶ between 0°C and 100°C, especially at 25°C. -6 K -1 Up to 1.1×10 -6 K -1 Especially for 1×10 -6 K -1 , and / or

[0152] • Contains alkalis and / or metals.

[0153] Another approach is a "sealing glass." Sealing glass is used to bridge the different coefficients of thermal expansion of metal and glass. Sealing glass is so "durably flexible" that it can bond to both metal and any glass simultaneously without cracking. Such glass can therefore bond a diamond layer to one side and a carrier glass to the other, acting like an elastic adhesive. This glass is thus an adhesion promoter that can be placed between the carrier glass side and the diamond layer side. While additional films with an expansion curve similar to diamond are still under development, various variations of sealing glass already exist. Therefore, an advantageous solution to this problem lies in fusing a suitable additional film of sealing glass as a capping layer onto quartz glass and applying a metal film onto the capping layer made of glass with a variable coefficient of thermal expansion.

[0154] Preferably, the metal thin film is applied by vapor deposition, cathode sputtering, electron beam evaporation, or electrolysis. The metal thin film should be applied to the carrier sheet with the most uniform thickness possible.

[0155] Preferably, the metal thin film is annealed to a defined crystallographic orientation during or after application.

[0156] Preferably, diamond powder, particularly diamond powder with a particle size of 5 nm to 40 nm, is applied to a metal film prior to cultivation. This is specifically carried out by the following steps: applying a liquid mixture containing diamond powder to the metal film and removing the liquid, particularly by centrifugation and / or evaporation.

[0157] Preferably, the metal film diffuses almost completely, especially completely, into the substrate through the thermal effects during chemical vapor deposition. At temperatures between 900°C and 1000°C (approximately 950°C) and residence times of 19 to 30 hours, the metal film (especially the nickel film) disappears more or less completely, especially when it is only 5 nm thick.

[0158] Preferably, prior to cultivation, an additional film made of mineral material (preferably silicon-containing or synthetic material) is present between the metal film and the carrier sheet.

[0159] Preferably, an additional film made of mineral material (preferably silicon-containing or synthetic material) is specified between the metal film and the carrier sheet.

[0160] Particularly preferably, the thickness of the additional film is 0.5 mm, more preferably 0.4 mm, and even more preferably 0.3 mm.

[0161] In particular, an additional film is clad onto a carrier sheet. This can preferably be done before the metal film is applied to the carrier sheet or the additional film.

[0162] Preferably, the additional film may contain an alkali or other metal in such a quantity that the diamond layer grown on the additional film will not peel off when cooled from the softening temperature of the additional film to room temperature, by means of long-term exposure to tensile stress generated on the diamond side during cooling.

[0163] According to an advantageous embodiment, the additional film can:

[0164] • With 1.8×10 -6 K -1 Up to 2.2×10 -6 K -1 Between, especially 2×10 -6 K -1 The coefficient of thermal expansion, or a temperature-dependent variable coefficient of thermal expansion, is 3.9 × 10⁻⁶ at 900°C to 1100°C, especially at 1000°C. -6 K -1 Up to 4.1×10 - 6 K -1 Especially for 4×10 -6 K -1 The value is 0.9 × 10⁻⁶ at temperatures ranging from 0°C to 100°C, especially at 25°C. -6 K -1 Up to 1.1×10 -6 K -1 Especially for 1×10 -6 K -1 ,

[0165] • and / or

[0166] • It has a softening temperature between 500°C and 650°C, especially 550°C.

[0167] • and / or

[0168] • It has a chemical composition that causes 3.9 × 10⁻⁶ ppm at 900°C to 1100°C, especially at 1000°C. -6 K -1 Up to 4.1×10 -6 K -1 Especially for 4×10 -6 K -1 The coefficient of thermal expansion is 0.9 × 10⁻⁶, and it undergoes a crystallization process when cooled from the operating temperature of the CVD process, resulting in a coefficient of thermal expansion of 0.9 × 10⁻⁶ between 0°C and 100°C, especially at 25°C. -6 K -1 Up to 1.1×10 -6 K -1 Especially for 1×10 -6 K -1 , and / or

[0169] • Contains alkaline substances and / or metals.

[0170] It should be understood that the additional film and the carrier sheet are made of different materials.

[0171] As described above, the method includes providing a carrier sheet made of glass (especially quartz glass) that is transparent to visible light (with a metal film on its upper side), preferably further including applying the metal film to the upper side of the carrier sheet, and growing a diamond layer as a cover sheet on the upper side of the metal layer by chemical vapor deposition.

[0172] When an additional film is disposed between the carrier sheet and the metal film, the step of providing a carrier sheet (with a metal film on its upper side) that is transparent to visible light made of glass (especially quartz glass) means that the metal film is indirectly disposed on the upper side. Accordingly, the step of applying the metal film to the upper side of the carrier sheet should be understood as applying the metal film indirectly to the upper side of the carrier sheet. The method preferably includes applying the additional film to the carrier sheet, wherein the metal film is applied to the additional film. Accordingly, when an additional film exists between the metal film and the carrier sheet, growing a diamond layer as a cover sheet on the upper side of the carrier sheet by chemical vapor deposition should be understood as growing a diamond layer as a cover sheet indirectly on the upper side by chemical vapor deposition.

[0173] Here, the metal film can diffuse into the additional film and, in particular, also into the carrier sheet.

[0174] The resulting watch mirror advantageously includes a carrier plate, an additional thin film, and a diamond layer as a cover plate, wherein the additional thin film is arranged between the carrier plate and the cover plate, and the diamond layer is fixedly connected to the combination of the carrier plate and the additional thin film.

[0175] The method for manufacturing diamond sheets (Variation 2) includes the following steps, wherein the above considerations also apply to the method:

[0176] (i) A substrate, preferably made of pure crystalline silicon, is provided, having a metal thin film on its upper side. Preferably, the method further includes applying the metal thin film to the upper side of the substrate. Since silicon already has a face-centered cubic crystal structure, the crystallographic orientation of the metal thin film on the silicon wafer is preferably not performed in the same manner as annealing the metal thin film on quartz glass. Here, nickel or copper is preferably already deposited in a suitable cubic structure when the metal thin film is applied to the silicon.

[0177] If the deposition of the additional metal layer (nickel or copper) is only insufficiently crystallographically oriented, the orientation can be perfected by additional annealing.

[0178] (ii) Furthermore, in this method, diamond wafers are grown by chemical vapor deposition (also known as the CVD method or chemical vapor deposition process). Microwave plasma chemical vapor deposition (MPCVD) or hot-wire CVD (HFCVD) is particularly employed here. The steps of this method are carried out, in particular, in an apparatus used to perform chemical vapor deposition.

[0179] (iii) After cultivation, the substrate is removed from the diamond sheet.

[0180] For the method of manufacturing diamond sheets, it is preferred to specify the use of semiconductor wafers as substrates.

[0181] For the method of manufacturing diamond sheets, it is preferred to specify the use of a thin film of metal, specifically nickel and / or copper. Preferably, more than half, and especially all, of the thin film is composed of at least one of these metals. Alloys of copper and nickel have proven advantageous for thin films.

[0182] For the method of manufacturing diamond wafers, it is preferred that the thickness of the metal film before growth is at most 30 nm, more preferably at most 20 nm, further preferably at most 10 nm, and most preferably at most 5 nm; preferably, the thickness of the metal film is at least 2 nm. During the process, the metal reacts with the silicon substrate and diffuses partially or completely into the substrate, thereby at least partially disappearing. This process has certain advantages because, for example, it produces silicon-nickel compounds that can inhibit the formation of polycrystalline carbon during diamond growth or facilitate the dissolution of unwanted non-diamond deposits with the aid of hydrogen.

[0183] For the method of manufacturing diamond sheets, it is preferred to specify that the thickness of the diamond sheet after cultivation is at least 30 μm and / or at most 2 mm.

[0184] For the method of manufacturing diamond sheets, it is preferred to specify that the metal thin film is applied by vapor deposition, cathode sputtering, electron beam evaporation, or electrolysis.

[0185] For the method of manufacturing diamond sheets, it is preferred to apply diamond powder onto a metal film before cultivation. This is particularly carried out by the following steps: applying a liquid mixture containing diamond powder onto the metal film and removing the liquid, especially by centrifugation and / or evaporation.

[0186] Furthermore, the present invention relates to a method for manufacturing a watch crystal (especially the aforementioned watch crystal), comprising the following steps:

[0187] • The method described above is used to manufacture diamond sheets (especially single-crystal or quasi-single-crystal sheets) as cover plates via heteroepitaxial growth, and includes the following steps:

[0188] ■ A substrate preferably made of pure crystalline silicon is provided.

[0189] ■ Apply a thin metal film, particularly made of copper and / or nickel, and / or with a thickness between 5 nm and 20 nm, onto the upper side of a silicon substrate.

[0190] ■ Preferably, the metal film is annealed and tempered.

[0191] ■ Apply diamond powder, especially a layer of DND (detonation nanodiamond), onto a (especially a conditioned) metal film.

[0192] ■ Diamond wafers are grown on the aforementioned metal thin films by chemical vapor deposition, particularly by microwave plasma chemical vapor deposition (MPCVD) or hot-wire CVD (HFCVD).

[0193] ■ Removing the silicon substrate along with the metal thin film from the diamond wafer, and

[0194] • Connect the cover plate (4) to a layer constructed as a carrier plate, the refractive index of which is lower than that of the cover plate and the thickness is greater than the wavelength of visible light, especially through a connecting intermediate layer.

[0195] The connecting intermediate layer here preferably corresponds to the aforementioned connecting intermediate layer. This means that the connecting intermediate layer can have the aforementioned features individually or in combination. Furthermore, all considerations and descriptions regarding the connecting intermediate layer also apply to this method. In this case, the diamond layer is a separate sheet and its growth substrate has been separated, and the connecting intermediate layer particularly exhibits a purely adhesive connection, which is placed between the carrier sheet (i.e., the carrier glass) and the cover glass after, but not before, the diamond layer growth. A laminate is preferred here, by means of which the carrier glass and the cover glass are laminated together. Furthermore, the present invention relates to a wristwatch, particularly a wristwatch, comprising a case and a crystal disposed on the case, which is a crystal according to the foregoing description of the crystal and / or a crystal manufactured according to one of the foregoing methods.

[0196] The present invention also relates to a wristwatch, particularly a wristwatch comprising a case and a crystal disposed on the case. The crystal is made of / manufactured from diamond, particularly from diamond alone without any additional layers. When the crystal is made solely of diamond, it has only one diamond plate. This plate can advantageously possess the characteristics of the aforementioned cover plate (alone or in combination).

[0197] Furthermore, the present invention relates to a method for manufacturing a single-crystal diamond wafer from at least two initial single-crystal diamond wafers. The method includes the following steps:

[0198] Provide at least two single-crystal initial diamond wafers,

[0199] A polycrystalline diamond substrate is arranged on a molybdenum substrate.

[0200] • Arrange at least two single-crystal initial diamond wafers on a polycrystalline substrate diamond wafer.

[0201] • Cultivating single-crystal diamond layers on at least two single-crystal initial diamond wafers via chemical vapor deposition (especially via microwave plasma chemical vapor deposition (MPCVD) or hot-filament CVD (HFCVD)).

[0202] • Separate a single-crystal diamond layer from at least two single-crystal initial diamond wafers to manufacture a single-crystal diamond wafer.

[0203] Arranging polycrystalline diamond substrates on molybdenum wafers and placing at least two single-crystal initial diamond wafers on the polycrystalline diamond substrates, then growing single-crystal diamond layers on the at least two single-crystal initial diamond wafers, can achieve a very uniform temperature distribution during diamond layer growth. This is because the lower polycrystalline diamond substrate absorbs (dissipates) the different temperatures at the edges of the smaller single-crystal initial diamond wafers and distributes them across the entire substrate before releasing them to the smaller wafers.

[0204] To better understand, the following will be mentioned.

[0205] The CVD process is exothermic, meaning it generates heat. Therefore, more heat is generated during growth at the edges of the diamond wafer than on the surface, because at the edges the diamond grows or elongates in two directions. The different thermal conductivity of molybdenum and diamond also contributes to this. The higher heat generates stress, which can cause the growing diamond wafer to crack. Furthermore, black polycrystalline carbon is formed at the hotter locations during the CVD process, rendering the diamond wafer unusable.

[0206] When a single-crystal diamond layer is grown on at least two single-crystal initial diamond wafers directly arranged on a molybdenum wafer, although a single-crystal diamond layer is produced, the layer bears the internal stress generated by the at least two initial diamond wafers due to the uneven heat distribution over the entire area of ​​the at least two initial diamond wafers or due to the defect locations between the initial diamond wafers (which are caused by temperature differences at the edges of the initial diamond wafers during the growth of the single-crystal diamond layer).

[0207] It should be understood that at least two initial single-crystal diamond wafers are each smaller than the diamond wafer to be manufactured or already manufactured.

[0208] This specifically means that the area of ​​at least two initial single-crystal diamond wafers is smaller than the area of ​​the diamond wafer to be manufactured or already manufactured.

[0209] It should also be understood that at least two single-crystal initial diamond wafers are arranged adjacent to each other on a polycrystalline substrate diamond wafer.

[0210] It should be understood that those skilled in the art will select different features—especially the absolute dimensions (particularly the thickness) of different components—in the above embodiments or in the embodiments according to the claims to form a technically reasonable combination.

[0211] Further details, advantages, and features of the invention are derived from the following description of embodiments with reference to the accompanying drawings. The drawings show:

[0212] Figure 1 A simplified schematic top view of the watch mirror according to a first embodiment of the present invention.

[0213] Figure 2 A simplified schematic cross-sectional view of the watch mirror according to the first embodiment,

[0214] Figure 3 A simplified schematic cross-sectional view of the watch mirror according to a second embodiment of the present invention.

[0215] Figure 4 A simplified schematic cross-sectional view of the watch mirror according to a third embodiment of the present invention.

[0216] Figure 5A simplified schematic cross-sectional view of the coating that can be used for the mirror according to the first, second, and third embodiments.

[0217] Figure 6 A simplified schematic cross-sectional view of the watch mirror according to the fourth embodiment of the present invention.

[0218] Figure 7 A simplified schematic diagram of the diamond crystal lattice structure as a face-centered cubic lattice structure.

[0219] Figure 8 A simplified diagram of the diamond crystal structure as a cube.

[0220] Figure 9 A simplified diagram of the diamond crystal structure as a cube.

[0221] Figure 10 A simplified schematic diagram of the diamond crystal structure in its natural crystalline form.

[0222] Figure 11 A simplified schematic diagram of a diamond manufacturing method for a watch crystal cover plate according to the first, second, third, or fourth embodiment is provided.

[0223] Figure 12 A simplified schematic cross-sectional view of a wristwatch with a crystal according to the first, second, third, or fourth embodiment.

[0224] Figure 13 A cleavage pattern of a diamond sheet.

[0225] Figure 14 Another cleavage mode of diamond sheets, and

[0226] Figure 15 Simplified schematic cross-sectional view of the watch mirror according to the fifth embodiment of the present invention

[0227] Figures 16 to 23 The process of the method of the present invention for manufacturing diamond sheets by growing on a silicon substrate according to the above-described embodiment 2 is illustrated in schematic form.

[0228] Figures 24 to 27 The process of manufacturing a watch mirror according to the above-described embodiment 1 is illustrated schematically, when an additional thin film is arranged between the carrier sheet and the cover sheet.

[0229] Figure 28 and 29 The invention relates to a method for manufacturing a single-crystal diamond wafer from at least two initial single-crystal diamond wafers.

[0230] The following reference Figure 1 and Figure 2 The watch mirror 1 according to the first embodiment of the present invention will be described in detail.

[0231] like Figure 1 As shown, the watch crystal 1 is circular. In particular, the watch crystal 1 can have a diameter of 40 mm. Other shapes of the watch crystal 1 are also possible.

[0232] from Figure 2 As can be seen, the watch crystal 1 is a monolithic crystal and comprises (only) a cover plate 4 and a layer constructed as a coating 5 (a single layer constructed as coating 5, or in other words, a single coating 5). The cover plate 4 is made solely of diamond. In particular, the cover plate 4 can be made of polycrystalline synthetic diamond or monocrystalline synthetic diamond. However, it is also conceivable that the cover plate 4 could be made of natural diamond. The cover plate 4, constructed solely of diamond, has the following advantages: it is 100% scratch-resistant and has a high-quality appearance.

[0233] Coating 5 is applied to the inner side 3 of the cover plate 4. (Refer to...) Figure 12 The figure shows a watch 40 constructed as a wristwatch, having a case 41, a strap 43, a dial 44, and at least one hand 42 for displaying the time. The inner side 3 of the cover 4 is the side of the cover 4 facing the interior space 410 of the case 41, the at least one hand 42, and the dial 44. "Facing" means that the inner side 3 of the cover 4 is closer to the interior space 410 of the case 41, the at least one hand 42, and the dial 44 than the outer side 2 of the cover 4. The outer side 2 is away from the interior space 410 of the case 41, the at least one hand 42, and the dial 44.

[0234] The coating 5 has a thickness 501 that is significantly greater than the wavelength of visible light. This thickness 501 of the coating 5 has the following advantages: no interference effect occurs in the coating 5 when light passes through the mirror 1.

[0235] The coating 5 extends to cover 100% of the surface, that is, it covers the entire surface of the cover plate 4 on its inner side 3. In particular, the coating 5 is disposed over the entire area of ​​the cover plate 4. However, it is also possible, especially when the coating 5 is manufactured by PVD, that it is not disposed over the entire area of ​​the inner side 3 of the cover plate 4. In this alternative embodiment, the coating 5 does not extend to the edge of the watch crystal 1, that is, it terminates before the edge of the watch crystal 1.

[0236] The cover plate 4 may have a thickness 502 of at least 0.1 mm, preferably at least 0.3 mm, more preferably at least 0.5 mm, more preferably at least 0.75 mm, and more preferably at least 1 mm. Preferably, this thickness is less than or equal to 0.5 mm. Particularly preferably, the thickness 502 of the cover plate 4 may be between 0.3 mm and 0.6 mm, preferably between 0.3 mm and 0.5 mm. This allows the optical advantages described in the general section to be achieved.

[0237] In particular, the cover plate 4 can be diamond with a type IIa crystal structure (lattice structure). In other words, the cover plate 4 can be type IIa diamond. Therefore, the cover plate 4 has the advantage that light can pass through the cover plate 4 with minimal interference.

[0238] The following reference Figures 7 to 10 To illustrate other features of mirror 1.

[0239] Figure 7 The diagram shows that diamond is, in principle, a face-centered cubic lattice cell (a "cell" with a calculated 8 carbon atoms). Figure 8 and Figure 9 The crystal structure of medium diamond can be represented as a cube marked with specific planes (shaded planes), while Figure 10 The image shows an octahedral structure marked with a specific plane (shaded plane). The octahedral structure is a characteristic feature of diamond in its natural crystalline form.

[0240] Diamond possesses specific cleavage planes in which unit cells can be relatively easily separated from each other. (See reference...) Figure 7 In a cubic lattice, there exist certain planes that are typically described by Miller indices. The relevant structural planes in a diamond lattice are primarily three cubic faces, which can be represented by Miller indices (100), (010), and (001).

[0241] In its natural crystalline appearance, cubic planes (100), (010) and (001) can be identified. These cubic planes are those faces of an octahedron that connect four of the eight vertices located in the same plane.

[0242] An octahedron has three possible planes, each connecting its four vertices. In cubic coordinates, these planes can be represented by Miller indices (100), (010), and (001). From a crystallographic perspective, these three planes are equivalent because the cube or octahedron representing the diamond crystal structure can be rotated in any direction, mapping the exact same diamond lattice atomic structure in the direction of each directly observed cube or octahedral face.

[0243] The second type of crystal plane that appears in a diamond cubic lattice is those faces that represent three of the six possible diagonal faces of the cube, which connect four of the eight vertices of the cube and each contain a coordinate vector in a coordinate system representation. These planes can be represented by Miller indices (110), (101), and (011).

[0244] The prominent crystal planes (110), (101), and (011) in the octahedron are those planes that extend parallel to an octahedron face, contain two vertices of the octahedron, and pass through the four triangular octahedron faces as angle bisectors. Here, the three crystal planes (110), (101), and (011) are also equivalent from the top view of the atomic lattice.

[0245] The third significant crystal plane that plays an important role in diamond is the plane that can be represented by the Miller index (111) in the cubic representation of the diamond lattice. This lattice plane (111) is represented as an octahedral face in an octahedron. Here, all four possible octahedral planes (there are four such planes in total, since every two octahedral faces are parallel to each other) are also equivalent from a schematic top view of the atomic lattice.

[0246] In a diamond lattice that can be represented as a plane using coordinate vectors, there exist three basic planes of diamond, which are represented in an octahedron as follows:

[0247] • The plane connecting the four vertices: according to Figure 8 The planes (100), (001), and (010)

[0248] • Or the plane connecting the four angle bisectors: according to Figure 9 The planes (110), (101), and (011)

[0249] • Or a plane extending parallel to the surface of the octahedron: according to Figure 10 The plane (111)

[0250] (111) The plane, which is a plane extending parallel to one of the four possible octahedral faces (each pair of octahedral faces is parallel to each other), is the cleavage plane along which single-crystal diamond can be very easily split, i.e., very easily split under the corresponding compressive load.

[0251] With this in mind, when the cover plate 4 is made of single-crystal diamond, one of its surfaces can extend parallel to one of the crystallographic planes (100), (010), or (001), or parallel to one of the crystallographic planes (110), (101), or (011). Therefore, the surface of the cover plate 4 forms an angle with the crystallographic plane (111), and also with the other three crystallographically equivalent planes of the octahedral face. The surface of the cover plate 4 is particularly the outward or inward facing surface; in other words, the surface of the cover plate 4 facing or away from the interior space 410 of the case 41 of the watch 40, the at least one pointer 42, and the dial 44. Therefore, the surface of the cover plate 4 does not extend perpendicular to the cleavage plane (111), thereby preventing the cover plate from breaking along the cleavage plane due to impact with the watch crystal 1. Such breakage occurs in… Figure 13As shown in the diagram. Furthermore, this surface does not extend parallel to the cleavage plane (111). Surface extending parallel to the cleavage plane (111) could also lead to... Figure 14 The fracture shown.

[0252] Therefore, the cover plate 4 and thus the crystal 1 are particularly shatterproof. When the cover plate 4 is made of polycrystalline diamond, the polycrystalline diamond can have nanocrystalline diamond cells (>5nm, <100nm) or microcrystalline diamond cells (>100nm), preferably greater than 20μm. Larger diamond cells have the following advantages: optical damage to the crystal 1, especially so-called haze (caused by light scattering), is reduced, which is usually caused by the diamond cells of polycrystalline diamond.

[0253] In particular, when using polycrystalline synthetic diamond as the cover plate 4, the nucleation side forms the inner side 3, and the growth side forms the outer side 2 of the cover plate 4. Therefore, when the watch crystal 1 is subjected to compressive loads, the inner side 3 can bend more easily and better withstand the tensile stress that occurs on the inner side 3. The compressive stress that occurs on the outer side 2 when the watch crystal 1 is subjected to compressive loads poses less of a problem for the cover plate 4 because diamond is very hard and pressure-resistant. With the aforementioned structure of the cover plate 4, a particularly shatterproof polycrystalline synthetic diamond can be achieved, thus realizing a particularly shatterproof cover plate.

[0254] According to a variant of the watch crystal 1 of the first embodiment, the watch crystal 1 may be made of diamond alone without any additional layers. This means that the variant watch crystal 1 does not have a coating 5, but only a cover plate 4.

[0255] Figure 3 A watch mirror 1 according to a second embodiment of the present invention is shown.

[0256] One difference between the watch crystal 1 according to the second embodiment and the watch crystal 1 according to the first embodiment is that the watch crystal 1 according to the second embodiment is constructed as a multi-element watch crystal, particularly a double-element watch crystal. This means that the watch crystal 1 according to the second embodiment includes a layer constructed as a support piece 6 in addition to the cover plate 4, which is fixedly connected to the cover plate 4. Furthermore, unlike the watch crystal 1 according to the first embodiment, the watch crystal 1 according to the second embodiment does not have a layer constructed as a coating 5 on the inner side 3 of the cover plate 4. However, such a coating 5 is also possible in the watch crystal 1 according to the second embodiment.

[0257] To connect the cover plate 4 to the carrier plate 6, the watch crystal 1 includes an intermediate layer 7 located between the cover plate 4 and the carrier plate 6. By providing the intermediate layer 7 between the cover plate 4 and the carrier plate 6 to manufacture the watch crystal 1—in other words, by manufacturing the watch crystal 1 as a laminated composite glass—particularly high shatter resistance can be achieved, because when an impact is applied to the watch crystal 1, the impact energy can be absorbed from the cover plate 4 through the intermediate layer 7 and also by the carrier plate 6. Furthermore, laminating the cover plate 4 and the carrier plate 6 is an economical method. Moreover, the provision of the connecting intermediate layer 7 results in an improved optical appearance of the watch crystal 1. In particular, since the refractive index difference between the corresponding optical media (diamond-intermediate layer) at the interface between the cover plate 4 and the intermediate layer 7 is smaller than the refractive index difference between diamond and air, the optical balance of the watch crystal 1 is improved.

[0258] The intermediate layer 7 can be thinner than the cover sheet 4 and / or the carrier sheet 6. However, the intermediate layer 7 can also be thicker than the cover sheet 4.

[0259] In particular, the intermediate layer 7 can have a thickness 504 between 0.1 mm and 0.3 mm. In particular, the thickness 503 of the carrier sheet 6 can be at least 0.3 mm, preferably at least 0.5 mm, more preferably at least 1 mm, and even more preferably at least 1.5 mm. Furthermore, the carrier sheet 6 can be thicker than the cover sheet 4.

[0260] In addition, the intermediate layer 7 may consist of at least one cured adhesive layer (preferably a cured UV adhesive), or at least one laminate containing / composed of EVA, PVB, Sentry glass or other laminated films.

[0261] Furthermore, the intermediate layer 7 can have a refractive index that differs from the refractive index of the carrier sheet 6 by at most + / -Δn = 0.4, preferably at most + / -Δn = 0.2, and most preferably equal to the refractive index of the carrier sheet 6. "Δn" represents the difference between the refractive index of the intermediate layer 7 and the refractive index of the carrier sheet 6. By using refractive indices that are very similar to those of the carrier sheet 6, reflection losses at the interfaces between these watch lens 1 components can be reduced, thereby further reducing the total reflection loss of the watch lens 1. In particular, the intermediate layer can have a refractive index between 1.4 and 1.6, especially 1.48.

[0262] The support plate 6 is advantageously made of a different material than the cover plate 4; that is, the support plate 6 is not made of diamond. In particular, the support plate can be made of glass, especially of a material with a coefficient of thermal expansion of 0.001 × 10⁻⁶. -6 K -1 Up to 2×10 -6 K -1The glass between the cover plate 4 and the carrier plate 6 is made of, in particular, quartz glass, microcrystalline glass (Sitall), Vycor, Zerodur, CerVit, plastic, or sapphire glass. This allows for a stable connection between the cover plate 4 and the carrier plate 6, regardless of changes in ambient temperature and / or during the lamination of the cover plate 4 and the carrier plate 6 by heating. Particularly preferably, the carrier plate 6 is made of quartz glass.

[0263] from Figure 3 It can also be seen that the watch crystal 1 includes multiple decorative elements 10 and multiple grooves 9. The number of decorative elements 10 is the same as the number of grooves 9. The decorative elements 10 are gemstones, especially diamonds. Here, the grooves 9 are formed in the support plate 6. Each groove 9 contains exactly one decorative element 10.

[0264] Each decorative element 10 is arranged in a corresponding recess 9 such that the upper region of the decorative element 10 is in direct contact with the connecting intermediate layer 7, and the region of the recess 9 below the contact area between the decorative element 10 and the wall of the recess 9 contains only air or a vacuum. Here, the upper region of each decorative element includes the table and crown facets of the gemstone. This achieves a high-quality appearance for the decorative element 10.

[0265] Figure 4 A watch mirror 1 according to a third embodiment of the present invention is shown.

[0266] The difference between the watch lens 1 according to the third embodiment and the watch lens 1 according to the second embodiment is that the watch lens 1 according to the third embodiment includes a plurality of layers configured as coatings 5.

[0267] Specifically, the watch lens 1 includes a first coating 5 (a first layer configured as coating 5) located between the cover plate 4 and the intermediate layer 7, disposed on the inner side 3 of the cover plate 4. Furthermore, the watch lens 1 includes a second coating 5 (a second layer configured as coating 5) located between the intermediate layer 7 and the support plate 6, disposed on the side of the support plate 6 facing the intermediate layer 7. A third coating 5 (a third layer configured as coating 5) is applied to the side of the support plate 6 facing the internal space 410 of the casing 41 of the watch 40.

[0268] In particular, the coating 5 gradually has a lower refractive index from the outside to the inside, that is, from the cover plate 4 to the support plate 6.

[0269] Figure 5 The layer with a structure of multiple coatings, specifically coating 5, is shown.

[0270] As a multi-coating system, coating 5 comprises multiple coating layers 5a stacked on top of each other, made of the same or different materials. Preferably, the coating layers 5a have progressively lower refractive indices from the outside to the inside. Therefore, the progressively decreasing refractive indices of the coating layers 5a can significantly reduce reflection losses that would occur at the transition between the cover plate 4 (especially the inner side 3 of the cover plate 4) and the air in a watch lens 1 without coating 5.

[0271] The lower refractive index from the outside to the inside, that is, the lower refractive index from the cover plate 4 to the support plate 6, means that when the watch mirror 1 is installed in the watch 40, the coating layer 5a that is closer to the interior space 410 of the housing 41 has a lower refractive index than the other coating layer 5a.

[0272] As mentioned above, Figure 2 The coating 5 of the watch mirror 1 according to the first embodiment can be as follows: Figure 5 The multiple coatings shown. However, Figure 2 The coating 5 of the mirror 1 according to the first embodiment can also be a single-layer coating.

[0273] Figure 6 A watch mirror 1 according to a fourth embodiment of the present invention is shown.

[0274] The difference between the watch lens 1 according to the fourth embodiment and the watch lens 1 according to the second embodiment is that the watch lens 1 according to the third embodiment includes multiple layers configured as anti-reflective coatings 8. The anti-reflective coatings 8 can be single layers or multiple layers.

[0275] Specifically, the first antireflective coating 8 is installed on the inner side 3 of the cover plate 4. The second antireflective coating 8 is installed on the inner side of the intermediate layer 7 between the cover plate 4 and the carrier plate 6, and the third antireflective coating 8 is installed on the side of the carrier plate 6 facing the internal space 410 of the housing 41 of the table 40.

[0276] By using the anti-reflection coating 8, the reflection loss of light when it is emitted from the medium on which the anti-reflection coating 8 is applied can be reduced, thereby improving the light output.

[0277] Reference Figure 11 The following describes a method for manufacturing watch mirror 1 according to one of the foregoing embodiments. In particular, Figure 11 The manufacture of synthetic diamond is shown, and the cover plate 4 of the aforementioned embodiment of the watch face 1 is thus manufactured.

[0278] The method first includes providing a substrate 31 (seed crystal) located on a reference plane 30. Furthermore, the method includes growing a synthetic diamond blank 32 on the substrate 31 along a growth direction 33 perpendicular to the reference plane 30. The growth of the synthetic diamond blank 32 can be performed, in particular, by microwave plasma chemical vapor deposition (MPCVD) or hot-filament CVD (HFCVD). Here, the diamond blank 32 can be grown along the growth direction 33 at a growth rate of less than 15 μm per hour, preferably less than 8 μm per hour, and more preferably less than 5 μm per hour. This allows for the production of a well-purified and therefore optically transparent diamond and, consequently, a cover plate 4. At a growth rate of less than 5 μm per hour along the growth direction 33, particularly high uniformity and optical purity of the grown diamond can be achieved. Therefore, a cover plate 4 with particularly high uniformity and optical purity can be manufactured.

[0279] The synthetic diamond blank 32 is cut and / or ground to manufacture the cover plate 4. In particular, the diamond blank 32 may be cut perpendicular to the growth direction 33 and / or ground in a plane perpendicular to the growth direction 33. By cutting the diamond blank 32 perpendicular to the growth direction 33, it can be cut into at least a plurality of usable cover plates 4 for a plurality of watch lenses 1. Alternatively, the diamond blank 32 may be cut into at least one usable cover plate 4 for one or more watch lenses 1 and at least one usable substrate 31, which can be used to grow another diamond.

[0280] In particular, when the substrate 31 is configured for heteroepitaxial growth, or when the substrate 31 is configured for homoepitaxial growth (where the substrate 31 itself is not made of diamond or not made of a polycrystalline fragmented diamond layer), the synthetic diamond blank 32 can be cut and / or ground off the substrate 31.

[0281] According to an alternative advantageous embodiment of the invention, a substrate having a large number of diamond particles can be used for homoepitaxial growth. Single-crystal diamond can also be used as substrate 31.

[0282] The diamond blank 32 is preferably subjected to post-treatment under high pressure (especially between 45,000 atm and 60,000 atm) and / or high temperature after cultivation to achieve improvement in color and / or final crystal structure. High pressure is particularly understood as pressure between 45,000 and 60,000 atm. High temperature is preferably understood as temperature between 1250 degrees Celsius and 1700 degrees Celsius.

[0283] The manufactured cover plate 4 is connected to one or more layers of the previously described watch lens 1 (if the watch lens 1 includes multiple layers) according to the construction of the watch lens 1. Therefore, to manufacture the watch lens 1 according to the first embodiment, a coating 5 is applied to the inner side 4 of the cover plate 4 after manufacturing the cover plate 4. To manufacture the watch lens 1 according to the third embodiment, a corresponding coating 5 is applied to the inner side 3 of the cover plate 4 after manufacturing the cover plate 4. Furthermore, two additional coatings 5 ​​are applied to the carrier plate 6. After the cover plate 4 and the carrier plate 6 are coated, they are connected to each other via an intermediate layer 7. To manufacture the watch lens 1 according to the fourth embodiment, an anti-reflective coating 8 is applied to the manufactured cover plate 4 and the carrier plate 6, and then the cover plate 4 and the carrier plate 6 are connected to each other via an intermediate layer 7.

[0284] Figure 15 A watch mirror 1 according to a fifth embodiment of the present invention is shown.

[0285] According to the fifth embodiment, the watch lens 1, in addition to the diamond cover plate 4, also includes a double layer 11 located on the outer side 2 of the cover plate 4. The double layer 11 has a diamond layer 12 and an additional layer 13 located between the cover plate 4 and the diamond layer 12. The refractive index of the additional layer 13 is lower than that of the cover plate 4 and the diamond layer 12.

[0286] The additional layer 13 is made of a dielectric material. The refractive index and thickness of the additional layer 13, as well as the thickness of the diamond layer 12, are selected such that reflections at the interface transition between the additional layer 13 and the diamond layer 12 are at least partially, and especially completely, compensated outward (i.e., away from the watch).

[0287] After manufacturing the cover plate 4 as described above, the outer side 2 of the cover plate 4 is connected to the double layer 11. In particular, an additional layer 13 is applied to the cover plate 4, i.e., its outer side 2. Then, a diamond layer 12 is applied to the additional layer 13, such that in the finished watch crystal 1, the additional layer 13 is arranged between the cover plate 4 and the diamond layer 12.

[0288] Figures 16 to 23 The process of the method of the present invention for manufacturing diamond wafers by growing them on a silicon substrate is illustrated in schematic form, particularly for implementing variant 2.

[0289] First, the CVD reactor 1001, as an apparatus for performing chemical vapor deposition, is equipped with a silicon substrate 1002 and a metal thin film 1003 applied thereon; for example, a nickel layer 5 nm or 10 nm thick, on which a diamond crystal layer 1004 with a particle size of 5 nm to 40 nm is applied. The diamond crystal 1004 is preferably DND (detonation nanodiamond) crystal, but it can also be manufactured by methods other than detonation. Due to the high surface energy of nickel and diamond, the diamond crystals are uniformly and densely distributed on the nickel film. The same applies to copper. For clarity, the CVD reactor 1001 only... Figure 16 As shown in the image.

[0290] As the CVD reactor 1001, a conventional MPCVD reactor (microwave plasma chemical vapor deposition reactor) can be used, for example. HFCVD reactors (hot filament chemical vapor deposition reactors) are also suitable. Furthermore, further reactors are suitable that use additional means (such as laser or ion bombardment) to deliver energy to the diamond growth surface.

[0291] Figure 16 First, we evacuate the reactor chamber of CVD reactor 1001 to remove all atmospheric gases. Then, while slowly heating, we first fill the reactor chamber with hydrogen (process gas) and methane (the gas carrying the carbon we want to deposit as diamond on the substrate). The hydrogen to methane ratio is approximately 10:1. The hydrogen flow rate is approximately 400 sccm, and the methane flow rate is approximately 40 sccm, but other flow rates and other ratios between H2 and CH4 can be chosen. We initially maintain the pressure in the reactor chamber at a very low level of approximately 25 Torr. During the process, we increase the pressure to a maximum of 135 Torr.

[0292] Figure 17 When the temperature reaches 200°C, the diamond crystals have not yet started to grow, but nickel begins to slowly diffuse into the silicon of the substrate 1002 and begins to form a nickel-silicon interlayer 1005 (composed of nickel and silicon).

[0293] During the remaining operation time of the first hour ( Figure 18 Starting at 400°C, polycrystalline non-diamond carbon (carbon 1006) forms between the individual seed crystal cells (diamond crystal 1004). However, this carbon is decomposed by process hydrogen and converted into methane or other hydrogen-carbon gases via plasma. Simultaneously ( Figure 19 Carbon 1006 also diffuses into the nickel-silicon interlayer 1005, or diffuses out again. The initially randomly arranged diamond crystals 1004 begin to grow slowly. During this process, they preferably grow in a (110) orientation or a (100) orientation. Since the (110) oriented crystals 4 grow slightly faster than the crystals in other orientations, an almost uniform growth orientation is quickly formed.

[0294] Figure 20 At 750°C, a polycrystalline non-diamond carbon (carbon 1006) layer 1007 is first formed on the diamond crystal 1004, but it will disappear at higher temperatures.

[0295] Figure 21 By absorbing carbon from methane gas, we obtain a growth structure in which a rapidly growing crystal steals energy from a slowly growing crystal and covers it with methane gas.

[0296] Figure 22 and 23 During further growth, a more or less uniform layer of rapidly growing diamond crystal 1004 was formed, with all crystals growing upwards in the same orientation.

[0297] Small silicon-nickel particles (1008) or polycrystalline black carbides may be deposited in the interface layer, but these particles are very small, below the threshold of visual visibility. At this point, the nickel layer has nearly or completely disappeared, and all the nickel has diffused into the silicon substrate.

[0298] After 2 to 3.5 hours, when about 10% to 15% of the diamonds are still in (111) orientation, after about 10 hours the ratio of (110) oriented diamonds to (111) oriented diamonds is close to 95% to 5%.

[0299] Therefore, we can now refer to them as single-crystal or "quasi-single-crystal" diamond layers or diamond sheets.

[0300] From a chemical perspective, the following process occurs, which applies to both implementation variant 1) and implementation variant 2):

[0301] In the process gas (or catalyst gas) H2, a hydrogen molecule splits, and two hydrogen atoms attach to two carbon atoms on the diamond sheet or diamond seed crystal, which then abandon their bonds to each other.

[0302] Then a hydrogen atom detaches from the methane gas and forms an H2 molecule with a hydrogen atom temporarily bonded to a carbon atom in the diamond lattice, thereby releasing the carbon atom, which can now bind to the free valence of a carbon atom in methane.

[0303] The same process occurs on the second carbon atom, which has a free valence after the removal of the H atom.

[0304] Finally, the H2 gas plasma removes one H atom from each of the semi-bonded methane gas molecules, allowing the two free valences of the two carbon atoms in the diamond to combine with each other.

[0305] Therefore, two new carbon atoms were attached to the diamond, and the diamond grew a little bit.

[0306] The growth rate can reach 8 μm per hour, and in some cases up to 10 μm per hour, depending on the temperature and gas mixture.

[0307] The subsequent "annealing" of the diamond wafers (i.e., "crystallization" of the diamond structure and color improvement in the HPHT reactor), as is common in synthetic diamond manufacturing, is not possible here. The dual-structure quartz-diamond glass may not withstand this process. Therefore, by keeping the growth rate low in this method, resulting in better color and a purer diamond partial structure, the subsequent annealing and crystallization in the HPHT method becomes redundant.

[0308] After growth, the finished diamond sheet is preferably mechanically polished on an accessible surface to achieve an absolutely smooth surface.

[0309] If, in implementing variant 1), we further embed an additional thin film, such as a thin layer of silicon (approximately 5 nm to 10 nm), between the carrier sheet 6 and the metal thin film 1003, this additional film allows polycrystalline "non-diamond carbon" (NDC) to be embedded in silicon (SiC) and then dissolved again during the plasma process. Therefore, the additional film can improve the optical quality of the component. Furthermore, due to its extremely small thickness, the additional film forms a film with a certain degree of elasticity, thus reducing the mechanical stress caused by the different coefficients of thermal expansion of quartz glass and diamond.

[0310] For the method of manufacturing diamond wafers without a carrier sheet (Example 2), we preferably use ordinary semiconductor wafers made of pure silicon. Silicon already has a perfect crystallographic structure, similar to diamond, i.e., a face-centered cubic crystal structure. Furthermore, the coefficient of thermal expansion of pure silicon semiconductor wafers is only 2.5 × 10⁻⁶. -6 K -1 Although this is still the coefficient of thermal expansion of synthetic diamond (1.0 × 10⁻⁶). -6 K -1 It is two and a half times larger than that of diamond. However, this is (excluding special glasses such as pure quartz glass) a coefficient of thermal expansion very close to that of diamond. For comparison, sapphire has a coefficient of thermal expansion of 6.0 × 10⁻⁶. -6 K -1 Float glass has a thickness of 9.2 × 10⁻⁶. -6 K -1 .

[0311] We apply a thin metal film, such as nickel, onto the wafer. The layer thickness should be approximately 5 nm or 10 nm. Nickel not only has the same crystallographic structure as diamond (face-centered cubic), but the cell size of nickel differs from that of diamond by only 1.5% (nickel 3.52 Å, diamond 3.57 Å). We then coat a silicon / metal thin film substrate with DND diamond powder. Afterward, we grow synthetic diamond on the substrate using a CVD method, preferably with a (110) or (100) crystallographic orientation. The growth rate is approximately 8 μm per hour. If we want to produce diamond glass with a thickness of approximately 1 mm, we need approximately 150 hours. Therefore, we remove the diamond-coated substrate from the reactor after approximately 6 days. We first remove the polycrystalline carbon from the edges of the diamond glass using a laser. Then we use a laser to cut the glass to the desired precise size and shape. We then grind it from both sides until the desired precise thickness is achieved.

[0312] Subsequently, it is preferable to apply a coating or multiple coatings to the inside.

[0313] In the implementation of variant 1), regarding the aspect of embedding an additional film between the carrier sheet 6 and the metal film 1003, as described above, reference will be made to... Figures 24 to 27 To provide a more detailed explanation.

[0314] Especially refer to Figures 24 to 27 The document describes a method for manufacturing a watch mirror 1, comprising the following steps: providing a carrier sheet 6 (with a metal thin film 1003 on its upper side) made of glass (especially quartz glass) that is transparent to visible light, and growing a diamond layer (especially single crystal or quasi-single crystal) on the upper side of the carrier sheet 6 by chemical vapor deposition (especially by microwave plasma chemical vapor deposition (MPCVD) or hot filament CVD (HFCVD)) as a cover sheet 4.

[0315] Prior to cultivation, an additional film 1009 made of mineral material is specified to exist between the metal film 1003 and the carrier sheet 6. The additional film 1009, made of glass, has a maximum thickness of 1 mm, preferably a maximum of 0.5 mm, more preferably a maximum of 0.4 mm, and even more preferably a maximum of 0.3 mm. Furthermore, the additional film 1009 has a thickness of 1.8 × 10⁻⁶ mm. -6 K -1 Up to 2.2×10 -6 K -1 Between, especially 2×10 -6 K -1The coefficient of thermal expansion is low, and the softening temperature is between 500°C and 650°C, especially 550°C. This means that the additional film 1009 is a low-melting-point film that can bridge the coefficient of thermal expansion between the carrier sheet 6 and the cover sheet 4 (diamond layer) made of quartz glass. The additional film 1009 can also be referred to as a cover layer or bridging glass.

[0316] Figure 24 The image shows a carrier sheet 6 made of quartz glass, as well as an additional thin film 1009 and a metal thin film 1003. The additional thin film 1009 is applied to the carrier sheet 6, and in particular, is fused onto it.

[0317] A metal film 1003, particularly made of nickel and / or copper, is applied onto the additional film 1009. For this purpose, the metal film 1003 can be deposited onto the additional film 1009 by vapor deposition. Other processes such as cathode sputtering, electron beam evaporation, or electrolysis can also be used to apply the metal film 1003 onto the additional film 1009. The metal film 1003 preferably has a defined crystallographic orientation. For this purpose, the metal film 1003 can be conditioned by annealing during or after application. Annealing aligns the initially amorphous metal film 1003 into a crystallographic orientation.

[0318] Diamond powder 1004, particularly a layer of DND (detonation nanodiamond), with a particle size of 5 nm to 40 nm, is applied onto a metal film 1003. This is carried out, in particular, by applying a liquid mixture (carrier liquid) containing diamond powder 1004 onto the metal film 1003 and removing the liquid, particularly by centrifugation and / or evaporation. During the growth process, the diamond grains of the diamond powder 1004 are oriented according to the lattice of the oriented metal film 1003 by surface tension.

[0319] To achieve Figure 24 The layout shown can be summarized by following these steps:

[0320] • Provide carrier plate 6 (quartz glass)

[0321] • Apply (especially cladding) the additional film 1009 to the carrier sheet 6.

[0322] • Apply (especially by vapor deposition) the metal thin film 1003 onto the additional thin film 1009.

[0323] • Preferably, the metal thin film 1003 is annealed and tempered.

[0324] • Apply diamond powder 1004 (especially a layer of DND (detonation nanodiamond)) onto (especially a conditioned) metal film 1003.

[0325] Figure 25The image shows the state where the cultivation, i.e., CVD process has begun and the diamond film 1010 has been deposited on the metal film 1003.

[0326] according to Figure 26 The metal film 1003 diffuses into the additional film 1009 and further into the carrier sheet 6, while the diamond film 1010 continues to grow.

[0327] Figure 27 The finished watch lens 1 is shown. Watch lens 1 includes a carrier sheet 6, an additional thin film 1009, and a diamond layer serving as a cover plate 4. The additional thin film 1009 is disposed between the carrier sheet 6 and the cover plate 4, and the cover plate 4 is fixedly connected to the assembly of the carrier sheet 6 and the additional thin film 1009. The cover plate 4 integrates the grains of diamond powder 1004, particularly detonated nanodiamond, thereby forming a uniform sheet. Figure 27 As shown, the metal film 1003 has disappeared.

[0328] Figure 28 (Top view) and Figure 29 (Side view) This relates to a method for manufacturing a single-crystal diamond wafer from at least two initial single-crystal diamond wafers.

[0329] First, at least two single-crystal initial diamond wafers 1102, one molybdenum wafer 1100, and one polycrystalline substrate diamond wafer 1101 are provided. Nine initial diamond wafers 1102 are provided here.

[0330] A polycrystalline diamond substrate 1101 is arranged on a molybdenum sheet 1100, wherein single-crystal initial diamond sheets 1102 are arranged adjacent to each other on the polycrystalline diamond substrate 1101. The area of ​​the substrate diamond sheet 1101 is at least equal to, and preferably greater than, the total area of ​​the initial diamond sheets 1102.

[0331] Then, a single-crystal diamond layer 1103 is grown on the single-crystal initial diamond wafer 1102 by chemical vapor deposition (especially by microwave plasma chemical vapor deposition (MPCVD) or hot filament CVD (HFCVD)). Figure 29 ).

[0332] The resulting single-crystal diamond layer 1103 is separated from the single-crystal initial diamond sheet 1102, particularly by laser, preferably by water jet, and preferably by gas jet, to form a single-crystal diamond sheet.

[0333] In addition to the foregoing written description, reference is made here to the accompanying drawings to supplement the disclosure of the invention.

[0334] List of reference numerals

[0335] 1. Watch crystal

[0336] 2. Outer side

[0337] 3. Inner side

[0338] 4. Cover plate

[0339] 5. Coating

[0340] 5a Coating layer

[0341] 6. Carrier plate

[0342] 7. Intermediate layer

[0343] 8 Anti-reflective coating

[0344] 9 grooves

[0345] 10 Decorative Elements

[0346] 11 Double Layer

[0347] 12 diamond layers

[0348] 13 Additional Layers

[0349] 30 Reference plane

[0350] 31 Seed crystal (substrate)

[0351] 32 Diamond blank

[0352] 33. Growth direction

[0353] Table 40

[0354] 41. Shell

[0355] 42 pointers

[0356] 43 watch strap

[0357] 44 dials

[0358] 410 Interior Space

[0359] 501 Coating Thickness (Coating Thickness)

[0360] 502 Cover plate thickness (cover plate thickness)

[0361] 503 Thickness of the bearing plate (bearing plate thickness)

[0362] 504 Intermediate Layer Thickness

[0363] 1001 CVD reactor

[0364] 1002 Silicon substrate (substrate)

[0365] 1003 metal film

[0366] 1004 diamond crystal

[0367] 1005 Nickel-Silicon Interlayer

[0368] 1006 carbon

[0369] 1007 polycrystalline layer

[0370] 1008 Silicon-Nickel Particles

[0371] 1009 Additional Film

[0372] 1010 Diamond Film

[0373] 1100 molybdenum sheet

[0374] 1101 Polycrystalline Substrate Diamond Sheet

[0375] 1102 Single-crystal initial diamond sheet

[0376] 1103 Single-crystal diamond layer

Claims

1. A watch crystal (1), particularly for wristwatches, comprising: A cover plate made of diamond (4), and • The layer constructed as a support sheet (6) has a lower refractive index than the cover sheet (4) and a thickness (503) greater than the wavelength of visible light. • and / or at least one layer constructed as a coating having a refractive index lower than that of the cover plate (4) and a thickness (501) greater than the wavelength of visible light.

2. The watch crystal (1) according to claim 1, wherein the cover plate (4) is the outermost layer of the watch crystal (1).

3. The watch crystal according to claim 1, comprising a double layer (11) on the outside of the cover plate (4), the double layer having a diamond layer (12) and an additional layer (13) between the cover plate (4) and the diamond layer (12), wherein the refractive index of the additional layer (13) is lower than that of the cover plate (4) and the diamond layer (12), and in particular wherein the diamond layer (12) is the outermost layer of the watch crystal (1).

4. A watch crystal (1), particularly for wristwatches, comprising: A cover plate (4) made of diamond, and a double layer (11) on the outside (2) of the cover plate (4), the double layer having a diamond layer (12) and at least one additional layer (13) between the cover plate (4) and the diamond layer (12), wherein the refractive index of the at least one additional layer (13) is lower than that of the cover plate (4) and the diamond layer (12), and in particular, the diamond layer (12) is the outermost layer of the watch lens (1).

5. The watch lens (1) according to any one of the preceding claims, wherein the cover plate (4): • Having a thickness (502) of at least 0.1 mm, preferably at least 0.3 mm, more preferably at least 0.5 mm, preferably at least 0.75 mm, preferably at least 1 mm, and / or having a thickness (502) of at most 3 mm, more preferably at most 2 mm, particularly preferably at most 1.2 mm; • And / or made of synthetic diamond; • And / or made of polycrystalline synthetic diamond or single-crystal synthetic diamond.

6. The watch mirror (1) according to any one of the preceding claims except claim 4, comprising a layer configured as a support piece (6) fixedly connected to the cover plate (4); particularly wherein the support piece • It has a thickness of at least 0.3 mm, preferably at least 0.5 mm, more preferably at least 1 mm, and most preferably at least 1.5 mm (503); • And / or thicker than the cover plate (4); • and / or made of a different material than the cover plate (4); • And / or made of glass, especially glass with a coefficient of thermal expansion of 0.001 × 10⁻⁶. -6 K -1 Up to 2×10 -6 K -1 Made of glass, especially quartz glass, microcrystalline glass, Vycor, Zerodur, CerVit, plastic, or sapphire glass, and / or Includes a layer configured as a support sheet (6), and an additional thin film (1009) made of mineral material located between the support sheet (6) and the cover sheet (4), wherein the layer is fixedly connected to the cover sheet (4), and in particular, wherein the additional thin film (1009) is: ■ With a capacity of 1.8 × 10 -6 K -1 Up to 2.2×10 -6 K -1 Between, especially 2×10 -6 K -1 The coefficient of thermal expansion, or a temperature-dependent variable coefficient of thermal expansion, is 3.9 × 10⁻⁶ at 900°C to 1100°C, especially at 1000°C. -6 K -1 Up to 4.1×10 -6 K -1 Especially for 4×10 -6 K -1 At temperatures ranging from 0°C to 100°C, and especially at 25°C, the value is 0.9 × 10⁻⁶. -6 K -1 Up to 1.1×10 -6 K -1 Especially for 1×10 -6 K -1 , and / or ■ It has a softening temperature between 500°C and 650°C, especially 550°C, and / or ■ It has a chemical composition that causes 3.9 × 10⁻⁶ ppm at 900°C to 1100°C, especially at 1000°C. -6 K -1 Up to 4.1×10 -6 K -1 Especially for 4×10 -6 K -1 The coefficient of thermal expansion is 0.9 × 10⁻⁶, and it undergoes a crystallization process when cooled from the operating temperature of the CVD process, resulting in a coefficient of thermal expansion of 0.9 × 10⁻⁶ between 0°C and 100°C, especially at 25°C. -6 K -1 Up to 1.1×10 -6 K -1 Especially for 1×10 -6 K -1 , and / or ■ Contains alkaline substances and / or metals.

7. The watch mirror (1) according to any one of the preceding claims except claim 4, comprising a layer configured as a support plate (6) fixedly connected to the cover plate (4); particularly wherein the support plate is made of glass, the glass... • Has a softening temperature between 500°C and 650°C, especially 550°C, and / or • It has a temperature-dependent variable expansion coefficient, which is 3.9 × 10⁻⁶ at 900°C to 1100°C, especially at 1000°C. -6 K -1 Up to 4.1×10 -6 K -1 Especially for 4×10 -6 K -1 The value is 0.9 × 10⁻⁶ at temperatures ranging from 0°C to 100°C, especially at 25°C. -6 K -1 Up to 1.1×10 - 6 K -1 Especially for 1×10 -6 K -1 , and / or • It has a chemical composition that causes 3.9 × 10⁻⁶ ppm at 900°C to 1100°C, especially at 1000°C. -6 K -1 Up to 4.1×10 -6 K -1 Especially for 4×10 -6 K -1 The coefficient of thermal expansion is 0.9 × 10⁻⁶, and it undergoes a crystallization process when cooled from the operating temperature of the CVD process, resulting in a coefficient of thermal expansion of 0.9 × 10⁻⁶ between 0°C and 100°C, especially at 25°C. -6 K -1 Up to 1.1×10 -6 K -1 Especially for 1×10 -6 K -1 , and / or • Contains alkaline substances and / or metals.

8. The watch crystal (1) according to claim 6 or 7, comprising a layer configured as an intermediate layer (7) located between the cover plate (4) and the support plate (6), wherein the intermediate layer (7) securely connects the cover plate (4) and the support plate (6); particularly wherein the intermediate layer (7): • Thinner than the cover plate (4); • And / or thinner than the carrier sheet (6); • And / or consists of at least one cured adhesive layer, preferably a cured UV adhesive or at least one laminate containing / composed of EVA, PVB, Sentry glass or other laminated films; • and / or having a refractive index that differs from the refractive index of the support sheet (6) by at most + / -Δn=0.4, preferably at most + / -Δn=0.2, or equal to the refractive index of the support sheet (6); • and / or having a refractive index between 1.4 and 1.6, especially 1.48; • and / or having a thickness of at least 0.05 mm, preferably at least 0.1 mm (504); • And / or have a thickness (504) of up to 0.8 mm, preferably up to 0.4 mm.

9. The watch crystal (1) according to any one of claims 1 or 3 is constructed as a monolithic watch crystal, having only a cover plate (4) and at least one layer constructed as a coating (5) on the cover plate (4), and in particular, also having a double layer (11).

10. The watch mirror (1) according to any one of the preceding claims includes at least one layer configured as a coating (5), wherein the coating (5) is applied to the inner side (3) of the cover plate (4).

11. The watch mirror (1) according to any one of the preceding claims includes at least one layer configured as a coating (5), wherein the coating (5) is configured as a multi-layer coating comprising a plurality of coating layers (5a) stacked on top of each other made of the same or different materials; preferably wherein the coating layers (5a) have progressively lower refractive indices from the outside to the inside.

12. The watch mirror (1) according to any one of the preceding claims, including claim 6, includes at least one layer configured as a coating (5), wherein the coating (5) is applied on the inner side (3) of the support sheet (6).

13. The watch mirror (1) according to any one of the preceding claims, wherein at least two, preferably all, layers, except for the layer configured as the intermediate layer (7), have progressively lower refractive indices from the outside to the inside.

14. The watch lens (1) according to any one of the preceding claims except claim 4, wherein the refractive index of the inner side of the cover plate (4) is reduced to at least 1.8, preferably at least 1.5, by at least one, preferably at least two, and more preferably at least three layers.

15. The watch mirror (1) according to any one of the preceding claims other than claim 4, comprising at least one layer configured as an antireflective coating (8), particularly applied to one or more layers whose refractive index is reduced to at least 1.8, preferably at least 1.5, wherein each antireflective coating (8) is matched to its respective adjacent medium.

16. The watch lens (1) according to any one of the preceding claims, wherein the cover plate (4) • It is diamond with a type IIa crystal structure. • and / or single-crystal synthetic diamond, wherein the surface of the cover plate (4) extends parallel to one of the crystallographic planes (100), (010) or (001), or parallel to one of the crystallographic planes (110), (101), (011), • And / or made of polycrystalline diamond, preferably having nanocrystalline diamond cells with a diameter greater than 1 nm, preferably greater than 50 nm, or microcrystalline diamond cells with a diameter greater than 1 μm, preferably greater than 50 μm.

17. The watch lens (1) according to any one of the preceding claims, wherein when polycrystalline synthetic diamond is used as the cover plate (4), the nucleation side constitutes the inner side (3) and the growth side constitutes the outer side (2) of the cover plate (4).

18. The watch face (1) according to any one of the preceding claims further comprises at least one decorative element (10), particularly a gemstone, which is arranged in a groove (9) formed in the support piece (6).

19. The watch face (1) according to claim 18, wherein the upper region of the decorative element (10) is in direct contact with the connecting intermediate layer (7), and / or wherein the region of the groove (9) below the contact area between the decorative element (10) and the wall of the groove (9) contains only air or vacuum.

20. A method for manufacturing a watch crystal (1), particularly a watch crystal (1) according to any one of the preceding claims except claim 4, comprising: • Provide a substrate (31) located on a reference plane (30), • A synthetic diamond blank (32) is grown on a substrate (31) along a growth direction (33) perpendicular to the reference plane (30), particularly by microwave plasma chemical vapor deposition (MPCVD) or hot-wire CVD (HFCVD). • Cut and / or grind the diamond blank (32) to manufacture the cover plate (4), and • Connect the cover plate (4) to a layer configured as a support plate (6), the refractive index of which is lower than that of the cover plate (4) and the thickness (503) is greater than the wavelength of visible light, and / or The cover plate (4) is connected to at least one layer configured as a coating (5), the refractive index of which is lower than that of the cover plate (4) and the thickness (501) is greater than the wavelength of visible light.

21. The method of claim 20, excluding claim 2, comprising the following steps: The outer side of the cover plate (4) is connected to a double layer (11) having a diamond layer (12) and an additional layer (13) located between the cover plate (4) and the diamond layer (12), wherein the refractive index of the additional layer (13) is lower than that of the cover plate (4) and the diamond layer (12).

22. A method for manufacturing a watch crystal (1), particularly a watch crystal (1) according to claim 4, the watch crystal being particularly for wristwatches, comprising: • Provide a substrate (31) located on a reference plane (30), • A synthetic diamond blank (32) is grown on a substrate (31) along a growth direction (33) perpendicular to the reference plane (30), particularly by microwave plasma chemical vapor deposition (MPCVD) or hot-wire CVD (HFCVD). • Cut and / or grind the diamond blank (32) to manufacture the cover plate (4), and • The outer side of the cover plate (4) is connected to a double layer (11) having a diamond layer (12) and an additional layer (13) located between the cover plate (4) and the diamond layer (12), wherein the refractive index of the additional layer (13) is lower than that of the cover plate (4) and the diamond layer (12).

23. The method according to any one of the preceding claims, comprising: • When using a substrate configured for heteroepitaxial growth, or when using a substrate configured for homoepitaxial growth, wherein the substrate itself is composed of diamond or of a polycrystalline fragmented diamond layer, the diamond blank (32) is separated from the substrate by cutting and / or grinding. • and / or cut the diamond blank (32) perpendicular to the growth direction (33), • And / or perpendicular to the growth direction (33), cut the diamond blank into at least a plurality of usable caps (4) or at least one usable cap (4) and at least one usable substrate (31), • And / or grind the diamond blank (32) in a plane perpendicular to the growth direction (33).

24. The method according to any one of the preceding claims, wherein: • Use a substrate configured for heteroepitaxial growth. • Alternatively, for homoepitaxial growth, a substrate with a large number of diamond particles may be used. • Alternatively, single-crystal diamond can be used as a substrate.

25. The method according to any one of the preceding claims, wherein the diamond blank (32) is subjected to high pressure and / or high temperature post-treatment after cultivation to achieve improvement in color and / or final crystal structure.

26. A method for manufacturing a watch crystal (1), particularly a watch crystal (1) according to any one of the preceding claims, wherein if the cover plate (4) is disposed directly on the support plate (6) or an additional thin film (1009) is disposed between the cover plate (4) and the support plate (6), the method comprises the following steps: • Provide a support sheet (6) made of glass, especially quartz glass, that is transparent to visible light, having a thin metal film on its upper side. • A diamond layer, especially a single crystal or quasi-single crystal, is grown on the upper side of the carrier sheet (6) by chemical vapor deposition through heteroepitaxial growth, especially by microwave plasma chemical vapor deposition (MPCVD) or hot filament CVD (HFCVD).

27. A method for manufacturing, particularly single-crystal or quasi-single-crystal diamond sheets as watch mirrors (1), especially cover plates (4) of watch mirrors (1) according to any one of the preceding claims, by heteroepitaxial growth, the method comprising the following steps: • A substrate (1002) preferably made of pure crystalline silicon is provided. • A metal thin film (1003), particularly made of copper and / or nickel, and / or with a thickness between 5 nm and 20 nm, is applied on the upper side of a silicon substrate (1002). • Preferably, the metal film is annealed and tempered (1003). • Applying diamond powder (1004), especially a DND (detonation nanodiamond) layer, onto a conditioned metal film. • Diamond wafers are grown on the aforementioned metal thin films via chemical vapor deposition, particularly via microwave plasma chemical vapor deposition (MPCVD) or hot-wire CVD (HFCVD). • Remove the silicon substrate (1002) along with the metal film from the diamond wafer.

28. A method for manufacturing a watch crystal (1), particularly a watch crystal (1) according to any one of the preceding claims concerning the watch crystal (1), comprising the following steps: • Using the method according to claim 26, a diamond sheet, especially a single crystal or quasi-single crystal, is fabricated via heteroepitaxial growth as a cover plate (4), and • In particular, the cover plate (4) is connected to the layer configured as a carrier plate (6) by means of a connecting intermediate layer (7), which has a lower refractive index than the cover plate (4) and a thickness (503) greater than the wavelength of visible light.

29. A watch (40), particularly a wristwatch, having a case (41) and a watch crystal (1) disposed on the case (41) according to any one of the preceding claims concerning the watch crystal (1) and / or a watch crystal manufactured according to any one of the preceding method claims.

30. A watch (40), especially a wristwatch, comprising a case (41) and a crystal (1) disposed on the case, the crystal being made of diamond, especially being made solely of diamond without any additional layers.

31. A method for manufacturing a single-crystal diamond wafer from at least two single-crystal initial diamond wafers (1102), comprising the following steps: • Provide at least two single-crystal initial diamond wafers (1102), • A polycrystalline diamond substrate (1101) is arranged on a molybdenum substrate (1100). • At least two single-crystal initial diamond wafers (1102) are arranged on a polycrystalline substrate diamond wafer (1101). • Single-crystal diamond layers (1103) are grown on at least two single-crystal initial diamond wafers (1102) by chemical vapor deposition, particularly by microwave plasma chemical vapor deposition (MPCVD) or hot-wire CVD (HFCVD). • Separate the single-crystal diamond layer (1103) from at least two single-crystal initial diamond wafers (1102) to manufacture a single-crystal diamond wafer.

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