A back (1) for a watch case (50), the back (1) including a first element (10) arranged so as to be screwed onto the watch case (50), and a second element (20) including an end face bearing a pattern (M), the second element (20) being mounted such that it can move in rotation about an axis (C) passing through the centre of the case (50), wherein the second element (20) has a brake arranged so as to hold same relative to the first element (10) in different angular positions about the rotational axis (C), the brake being disposed between the first and second elements (10, 20).

The present invention relates to a timepiece component comprising on at least one part of its surface a coating formed of one or more layers of organic pigments.

A watch dial includes a substrate, a protruding portion formed on the substrate by laser machining, and a coating layer provided around the protruding portion. At least a portion of an upper surface of the protruding portion is exposed from the coating 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.

Digital/analog art clocks and vertical clocks are described.

A water-resistant watch case of a diving watch, includes at least one back mounted on a lower side of a middle part, and a crystal mounted on an upper side of the middle part. The crystal includes an annular peripheral surface to be fastened with an amorphous metal gasket on an inner annular surface that is complementary in shape, on the upper side of the middle part. The annular peripheral surface of the crystal is inclined towards the inside of the watch case at a determined angle less than 90° relative to a central axis perpendicular to a plane of the watch case to distribute stresses between the crystal and the middle part due to the water pressure during a dive. The annular peripheral surface and the inner annular surface are conical in shape.

A water-resistant watch case of a diving watch, includes a back mounted on a lower side of a middle part, and a crystal mounted on an upper side of the middle part. The crystal includes an annular peripheral surface mounted by a first portion of an annular gasket made of amorphous metal on an inner annular surface that is complementary in shape, on the upper side of the middle part. A second portion of the gasket on the first portion of the gasket maintains the crystal against the middle part. The annular peripheral surface of the crystal is inclined towards the inside of the watch case at an angle less than 90° relative to a central axis perpendicular to the plane of the watch case to distribute stresses between the crystal and the middle part due to the water pressure.

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 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 system and method that enables a person to understand the concept of “a timed schedule” and/or a “timed task”, so that they can more efficiently and/or effectively perform vocational and other life tasks and skills.

A system and method that enables a person to understand the concept of “a timed schedule” and/or a “timed task”, so that they can more efficiently and/or effectively perform vocational and other life tasks and skills.