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).

The present invention concerns a holographic display device incorporated in a timepiece device comprising at least one movable hand, having a light source at its peripheral end, and a watch glass comprising at least one hologram at its periphery, said light source being arranged on the hand so that it reconstructs said hologram when it moves into a predetermined angular sector.

The present invention concerns a holographic display device incorporated in a timepiece device comprising at least one movable hand, having a light source at its peripheral end, and a watch glass comprising at least one hologram at its periphery, said light source being arranged on the hand so that it reconstructs said hologram when it moves into a predetermined angular sector.

A method for marking a product (1) with a photoluminescent mark, said mark comprising a photoluminescent portion (10) which is transparent under normal light conditions and revealed by photoluminescence under UV illumination, said mark further comprising a non photoluminescent portion (9) which is transparent under normal light conditions as well s under UV illumination, said method comprising: deposing on said product a stack, said stack comprising alternatively layers (2,4) such as AIN, with a thickness of less than 1 micron and layers (3) of a second material, such as GaN with a thickness of less than 10 nm; raising the transparency of said non photoluminescent portion (10) with a deposition of transparent material (6) or incorporation of ions into said non photoluminescent portions.

A method hardens an anti-reflection treatment deposited on a transparent substrate that includes a top surface and a bottom surface which extends remotely from the top surface. The anti-reflection treatment includes depositing at least one anti-reflection layer of at least one material on at least one of the top and bottom surfaces of the transparent substrate, bombarding the at least one top or bottom surface on which the at least one anti-reflection layer has been deposited using a singly-charged and/or multi-charged ion beam produced by a singly-charged and/or multi-charged ECR electron cyclotron resonance ion source. The method produces a transparent substrate having undergone an anti-reflection treatment such that at least one of the top and bottom surfaces of the transparent substrate is coated with at least one anti-reflection layer of at least one material, whereby ions are implanted in the at least one anti-reflection layer.

A method for marking a sapphire watch crystal, through the interaction between a laser beam and the sapphire. The beam is focused on a point inside the crystal and the interaction is such that it produces a rectilinear opaque area, which is parallel to the upper surface of the crystal or perpendicular to the surface. The orientation of the opaque area depends on the mode of operation applied. According to the hatching mode of operation, the beam is scanned along one or more linear paths, producing opaque lines inside the crystal, which are parallel to the upper surface. The perforation mode of operation produces distinct opaque areas, obtained by discontinuous operation of the beam on a number of juxtaposed points. According to this latter mode of operation, the opaque areas extend in the direction perpendicular to the upper surface of the crystal.

A method for marking a product (1) with a photoluminescent mark, said mark comprising a photoluminescent portion (10) which is transparent under normal light conditions and revealed by photoluminescence under UV illumination, said mark further comprising a non photoluminescent portion (9) which is transparent under normal light conditions as well as under UV illumination, said method comprising: deposing on said product a stack, said stack comprising alternatively layers (2, 4), such as AlN, with a thickness of less than 1 micron and layers (3) of a second material, such as GaN, with a thickness of less than 10 nm; raising the transparency of said non photoluminescent portion (10) with a deposition of transparent material (6) or incorporation of ions into said non photoluminescent portions.

A transparent timepiece component, in particular a watch glass, has a substantially planar or curved interior surface, and has mainly a transparent material colored by a zone of modified chemical composition within the component through an introduction of at least one coloring chemical element of the transparent material, this zone of modified chemical composition extending in one part only of the total thickness of the timepiece component.

A cover for an electronic device and methods of forming a cover is disclosed. The electronic device may include a housing, and a cover coupled to the housing. The cover may have an inner surface having at least one of an intermediate polish and a final polish, a groove formed on the inner surface, and an outer surface positioned opposite the inner surface. The outer surface may have at least one of the intermediate polish and the final polish. The cover may also have a rounded perimeter portion formed between the inner surface and the outer surface. The rounded perimeter portion may be positioned adjacent the groove. The method for forming the cover may include performing a first polishing process on the sapphire component using a polishing tool, and performing a second polishing process on the groove of the sapphire component forming the cover using blasting media.

A striking watch is provided with an acoustic radiating membrane made of metallic material or amorphous metal. The membrane takes the form of a loop with walls of a certain thickness to be connected by a first edge portion to a middle part of a watch case and by a second edge portion to a bezel fixed to a watch crystal. The bezel connected to crystal is movable with respect to the case middle via the membrane during the vibration of membrane once a sound is generated by a watch striking mechanism in the watch case. The membrane is configured with a wall of a specific thickness in an active region dependent on the mass of the bezel connected to the crystal, to obtain a frequency f.sub.0 of a first vibration mode.