A mechanical or electromechanical timepiece including a watch case delimiting an internal volume, the watch case including a back delimiting the watch case at the bottom; a crystal closing the watch case at the top, the crystal defining a useful display aperture; a middle part connecting the back and the crystal to one another; a horological movement housed in the internal volume of the watch case; at least one hand for displaying information visible via a useful display aperture and rotated with respect to the watch case by the horological movement with at least one driving belt extending at least partially in the useful display aperture, the timepiece includes the internal volume of the watch case filled with a fluid wherein at least one driving belt is submerged, and wherein the driving belt is made of a material wherein the optical refractive index is equal or substantially equal to that of the fluid.

A timepiece glass, in particular a watch glass, wherein it comprises an optical device comprising at least one lens intended to enlarge an indication supplied by a timepiece, said lens comprising at least one aspherical face comprising at least one section passing through a vertical plane comprising an optical axis of vertical direction z, of which at least one outline can be defined by the following equation:

[00001]$z\left(r\right)=\frac{r^2}{R\left(1+\sqrt{1-\left(1-\right).Math..Math.\frac{r^2}{R^2}}\right)}+{}_4.Math.r^4+{}_6.Math.r^6+\mathrm{.Math.}$

in which R is the nominal radius of curvature, k is the constant of conicity, and .sub.(4,6, . . . ) is or are coefficient(s) of asphericity, and in which at least the constant of conicity k and/or at least one coefficient of asphericity is different from zero.

A display system includes a watch having a watch face; and an intelligent display system. The display system includes a display panel, a selectively opaque panel, a memory having programming instructions, and a controller in communication with the display panel and the selectively opaque panel, and the memory. The display system is operable in each of: (a) display mode wherein the display panel is actuated by the controller to display image content, and at least a portion of the selectively opaque panel is opaque; (b) a transparent mode wherein the display panel does not display image content, the selectively opaque panel is substantially transparent, and the watch face is substantially visible; and (c) an augmented reality mode wherein the display panel is actuated by the controller to display image content, and the selectively opaque panel is substantially transparent, the watch face being substantially visible behind the display system.

A method for fabrication of a composite component including a first material containing steel 316L and a second material containing zirconia powder formed in a single sintering.

Method for cutting a watch crystal along a contour in a plate of transparent material, with the following steps: making, on a first side of the plate, a first cut line or kerf to form a first chamfer, for each crystal of the plate; turning the plate over and marking the position of the first chamfers or of a previously made machined marking; making, on a second side, a second cut line or kerf to form a second chamfer, for each crystal; separating the crystals by machining through the plate at each contour to form an edge of the crystal.

A method for fabrication of a micromechanical part made of a one-piece synthetic carbon allotrope based material, the method including: forming a substrate with a negative cavity of the micromechanical part to be fabricated; coating the negative cavity of the substrate with a layer of the synthetic carbon allotrope based material in a smaller thickness than the depth of the negative cavity; and removing the substrate to release the one-piece micromechanical part formed in the negative cavity.

A method for fabrication of a micromechanical part made of a one-piece synthetic carbon allotrope based material, the method including: forming a substrate with a negative cavity of the micromechanical part to be fabricated; coating the negative cavity of the substrate with a layer of the synthetic carbon allotrope based material in a smaller thickness than the depth of the negative cavity; and removing the substrate to release the one-piece micromechanical part formed in the negative cavity.

A watch case includes a case middle made of plastic or electroformed material and a crystal. The crystal or the case middle includes elbowed catches that are each insertable in a bayonet fitting in a recess of the case middle or the crystal. The case also includes a rotation stop angularly securing the case middle and the crystal in an angular position such that a part of each catch is frontally locked behind a holding surface of the case middle or of the crystal. The rotation stop is frontally snap-fitted on the case middle and/or the crystal by snap-fit fingers that cooperate with a complementary stop surface of the case middle and/or of the crystal.

An optical component includes a base material and an antireflection film containing silica particles, wherein the porosity of the antireflection film is 15% by volume or more and 36% by volume or less. The number-based average particle diameter of the silica particles is preferably 0.5 nm or more and 4.0 nm or less. The antireflection film is preferably formed by using a composition containing the silica particles and a dispersion medium for dispersing the silica particles. The thickness of the antireflection film is preferably 50 nm or more and 120 nm or less.

A method of manufacturing an object including: impregnating a material comprising a plurality of boron nitride structures, the boron nitride structures comprising boron nitride nanotubes, or a hybrid of two or more forms of crystalline boron nitride structures, with a matrix material to form a composite material; moulding the composite material; and curing the composite material, wherein the object is at least partially fabricated from the composite material.