| abstract |
A process and device for shaping surfaces, in particular lenses, by laser machining of the surfaces, are preferably used for photorefractive ceratectomy and for shaping ophthalmologically exact contact lenses. In order to ensure an at least acceptable partial correction of the surface to be machined after a sudden interruption of the surface machining process, the device has a scanning pulsed laser (1), a beam shaping unit (2) and a laser beam deflecting unit (3) which deflects the laser beam onto a surface (4) to be machined. The laser beam deflecting unit (3) and the beam shaping unit (2) can be controlled by a controlling unit (5) with co-operating first (6) and second (7) input units, a computing unit (8) to which the data from the first and second input units (6; 7) are supplied, a block generator (9) to which the data from the computing unit (8) are supplied and in which the individual laser machining co-ordinates for removing any predetermined individual layer of the surface are mutually associated, and a sequence generator (10) to which the data generated by the block generator (9), gathered into blocks which correspond to an individual machining zone, are supplied, and which orders the individual blocks into a predetermined sequence. A particular block sequence transmitted by the sequence generator (10) acts upon the laser beam deflecting unit (3) and beam shaping unit (2) in such a way that a complete partial correction of the surface (4) to be machined is ensured for each block sequence. Also provided is a central processing unit (11) which co-ordinates in a predetermined manner the switching and control of at least the laser unit (1), the beam shaping unit (2; 21) and the laser beam deflecting unit (3) depending on the control data from the control unit (5). |