In one embodiment, a surface has a laser-beam machined area including an array of micro-sized conical pillars that are arranged in orthogonal rows and columns across the surface and that extend upward, the conical pillars defining deep troughs between them that are configured to absorb electrons, electromagnetic radiation, or both, the conical pillars tapering from relatively wide bases to pointed tips, the conical pillars comprising outer surfaces that are covered with a plurality of nanoparticles.

A decoating method for the edge decoating of glass sheets, the glass sheets having at least on one of their two glass surfaces a protective coating in the form of a peel-off protective film or in the form of a polymer protective layer that cannot be peeled off, and preferably having a functional coating situated under the protective coating, the protective film being partially mechanically removed, in particular ground away, for the edge decoating, in the form of at least one film strip, laser traces being introduced into the protective film before the mechanical removal of the film strip, and the laser traces being introduced in such a way that the film strip is removed in the form of individual film strip partial pieces separated from one another by the laser traces; or the polymer protective layer being removed using laser radiation.

A label (1; 50) for a tyre (100) of vehicle wheels comprises: an external surface (2) which is intended to remain visible when said label (1; 50) is coupled to a sidewall (102) of the tyre, an internal surface (3) which is opposite the external surface (2), a plurality of recesses (10) which are formed at the external surface (2) and which are not open at said internal surface (3) and which are capable of generally defining at least one portion of information which is set out on the label. The plurality of recesses (10) are formed on a first layer (4) of the label (1; 50) which is made of an elastomer material which is compatible with the elastomer material of the sidewall (102). The first layer (4) is partially vulcanized and has a degree of vulcanization corresponding to a value between T.sub.30 and T.sub.60.

A label (1; 50) for a tyre (100) of vehicle wheels comprises: an external surface (2) which is intended to remain visible when said label (1; 50) is coupled to a sidewall (102) of the tyre, an internal surface (3) which is opposite the external surface (2), a plurality of recesses (10) which are formed at the external surface (2) and which are not open at said internal surface (3) and which are capable of generally defining at least one portion of information which is set out on the label. The plurality of recesses (10) are formed on a first layer (4) of the label (1; 50) which is made of an elastomer material which is compatible with the elastomer material of the sidewall (102). The first layer (4) is partially vulcanized and has a degree of vulcanization corresponding to a value between T.sub.30 and T.sub.60.

A spark plug that prevents a decrease in strength of a member to which a mark is attached while ensuring a readability of the mark, and a method of manufacturing the spark plug. The spark plug is configured to ignite an air-fuel mixture in an internal combustion engine. The spark plug includes: a mark formed of an oxide film generated on a surface of a metallic member or is formed of the metallic member and the oxide film; and a coating material covering the whole mark and allowing transmission of light.

A spark plug that prevents a decrease in strength of a member to which a mark is attached while ensuring a readability of the mark, and a method of manufacturing the spark plug. The spark plug is configured to ignite an air-fuel mixture in an internal combustion engine. The spark plug includes: a mark formed of an oxide film generated on a surface of a metallic member or is formed of the metallic member and the oxide film; and a coating material covering the whole mark and allowing transmission of light.

A method for processing a transparent workpiece includes forming a contour of defect in the transparent workpiece and separating the transparent workpiece along the contour using an infrared laser beam. During separation, the method also includes detecting a position and propagation direction of a crack tip relative to a reference location and propagation direction of an infrared beam spot, determining a detected distance and angular offset between the crack tip and the reference location of the infrared beam spot, comparing the detected distance to a preset distance, comparing the detected angular offset to a preset angular offset, and modifying at least one of a power of the infrared laser beam or a speed of relative translation between the infrared laser beam and the transparent workpiece in response to a difference between the detected distance and the preset distance and between the detected angular offset and the preset angular offset.

A method for processing a transparent workpiece includes forming a contour of defect in the transparent workpiece and separating the transparent workpiece along the contour using an infrared laser beam. During separation, the method also includes detecting a position and propagation direction of a crack tip relative to a reference location and propagation direction of an infrared beam spot, determining a detected distance and angular offset between the crack tip and the reference location of the infrared beam spot, comparing the detected distance to a preset distance, comparing the detected angular offset to a preset angular offset, and modifying at least one of a power of the infrared laser beam or a speed of relative translation between the infrared laser beam and the transparent workpiece in response to a difference between the detected distance and the preset distance and between the detected angular offset and the preset angular offset.

A method for laser-marking an iron-based sintered body includes a first step of forming with a first laser beam a plurality of dotted recesses with a predetermined depth in an identification mark area of a surface of an iron-based sintered body, and a second step of flattening with a second laser beam the surface within the identification mark area other than the dotted recesses. The first laser beam has an irradiation energy per unit area greater than an irradiation energy per unit area of the second laser beam.

A method for laser-marking an iron-based sintered body includes a first step of forming with a first laser beam a plurality of dotted recesses with a predetermined depth in an identification mark area of a surface of an iron-based sintered body, and a second step of flattening with a second laser beam the surface within the identification mark area other than the dotted recesses. The first laser beam has an irradiation energy per unit area greater than an irradiation energy per unit area of the second laser beam.