Patent EP-2184127-A1 (EP)
Inventor: PETSCH TINO
IPC: B41M5/26
Filed: 2009-10-26
Abstract: The method for the production of a durable marking in an optical element that consists of a material transparent in visible spectral region, comprises irradiating a marking area of the optical element with laser radiation (125) for producing local surface near material variations in such a way that the marking of specific form and size is produced. The laser radiation has a processing wavelength of 1.1-9.2 mu m, which is used for the partial absorption with a transmission grade of 75-95% for the material of the optical element. The laser radiation has a processing wavelength of 1.5-5.0 mu m. The method for the production of a durable marking in an optical element that consists of a material transparent in visible spectral region, comprises irradiating a marking area of the optical element with laser radiation (125) for producing local surface near material variations in such a way that the marking of specific form and size is produced. The laser radiation has a processing wavelength of 1.1-9.2 mu m, which is used for the partial absorption with a transmission grade of 75-95% for the material of the optical element. The laser radiation has a processing wavelength of 1.5-5.0 mu m. The material of the optical element is plastic material or other plastic material suitable for ophthalmic material. The optical element consists of plastic material in an area to be modified. The radiation parameter of the laser radiation is adjusted in such a way that a laser induced volume enlargement is produced without material ablation in the surface near area. Structure elements are produced in the marking area against the non-radiating area that is produced with an unwounded surface that is continuously crooked over a volume enlarging area. The optical element is equipped with a coating covering the marking area and the plain structure element is produced through the coating. The coating is absorption free and/or modification resistant for the processing wavelength and/or consists of inorganic material. The sublime structure elements are formed without destruction of the coating. A thulium-doped, holmium-doped or erbium-doped fiber laser is used as laser beam source (120). A glass lens, a contact lens or intracular lens is equipped on a surface produced with optical quality, with the marking. A laser radiation focusing in a focusing area or projecting by a mask on an illumination spot is produced and the marking area of the optical element to be irradiated is irradiated with the laser radiation for producing local surface-near material variations. A relative movement is produced between the optical element and the laser radiation so that the laser radiation irradiates different places of marking area and the marking is produced in predetermined size and form. The intensity distribution of the laser radiation is influenced within the laser radiation through beam generation. For beam generation, a beam generation device is used with beam generation element from contour mask, grey shade mask, refractive optical element or diffractive optical element. An independent claim is included for a device with a substrate holder for the reception of optical element, a laser system and beam guiding system.