A watch glass includes a first glass, second glass and a decorative element, in particular a gemstone. Here, the first glass and the second glass are connected to one another via a connecting intermediate layer. The first glass includes a continuous recess. The decorative element includes a base region, which is arranged settingless in the recess of the first glass and in direct contact with the connecting intermediate layer. Further, a watch can include such a watch glass.

An ornamental part, for example for a timepiece, jewellery or telephone, in particular a watch case middle, and its manufacturing method, the part at least partly including a hard material having a Vickers hardness greater than 1000 HV, the method including the following main steps: a step of producing a precursor from a mixture of at least one powder material with a binder, a step of injecting the precursor into a mould in order to form a green body, a step of sintering the green body in order to form a body of the future part from the hard material, and a step of depositing a polymer material coating on one face of the part, the deposition being carried out by moulding on the body, in particular by injection into a mould, the coating and the hard material being inseparable.

An ornamental part, for example for a timepiece, jewellery or telephone, in particular a watch case middle, and its manufacturing method, the part at least partly including a hard material having a Vickers hardness greater than 1000 HV, the method including the following main steps: a step of producing a precursor from a mixture of at least one powder material with a binder, a step of injecting the precursor into a mould in order to form a green body, a step of sintering the green body in order to form a body of the future part from the hard material, and a step of depositing a polymer material coating on one face of the part, the deposition being carried out by moulding on the body, in particular by injection into a mould, the coating and the hard material being inseparable.

An optical component includes a base material and a film containing silica particles and conductive transparent metal oxide particles. The conductive transparent metal oxide particles are preferably composed of SnO.sub.2. The number-based average particle diameter of the conductive transparent metal oxide particles is preferably 0.8 nm or more and 5.0 nm or less. When the content of the silica particles in the film is represented by Xs (vol %) and the content of the conductive transparent metal oxide particles in the film is represented by Xc (vol %), it is preferred to satisfy the following relationship: 0.003Xc/Xs0.12.

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.

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.

A crystal/glass or screen of an apparatus intended to display an information visible to a user includes on its outer surface a transparent protective film with a convex outer surface, constituting a lens in order to facilitate reading. The transparent protective film constituting a lens is a layer (2) of transparent sapphire glass material having an anti-scratch surface. This layer (2) includes a convex outer surface forming a lens and an inner surface carrying a transparent repositionable glue film (4) by which said layer (2) can be removably glued to the outer surface of the crystal or of the screen (1).

A watch glass (1) has a near field communication (NFC) module (3) which includes at least one microcircuit (3.2) connected to an antenna (3.1). A watch (2) is equipped with such a glass (1). A method produces such a watch glass (1).

The wristwatch includes a case middle (3) and a load-reacting surface (2a) which is a surface of a load-reacting ring (2) distinct from the case middle (3), and a protective casing including the crystal (1), the case middle (3), and the load-reacting ring (2) housed within the case middle (3) including the load-reacting surface (2a) against which the crystal (1) bears, and a back (4) bearing against the load-reacting ring (2).

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.