| Laser marking is a kind of technique using heat effect of laser to ablate meterials on object surface so as to leave over permanent press. Compared with traditional press methods including electrochemistry method etc, laser marking has many merits such as no pollution, high speed, high quality, good flexibility, without-contact workpiece and so on. Laser marking machine is an integrated machine-electricity facility that integrates many techniques referring to laser, optics, exactmachine, computer etc into a whole. It is mainly composed of laser machine, optical system and controller, of which the controller is the kernel parts. Along with the flying development of computer technique, price relations of performance enhance constantly, numerical system basing on computer has become the mainstream of control-system development.The task is using computer to control marking process, during the whole research, including the collectivity design of laser-marking, control interface of laser-marking, control system of laser-marking and marking experiment. To reduce the marking distortion, using the vertical 2-dimension galvanometer distributing and Fθ field lens focalize, the distance of the second galvanometer to the machining plane is the focus f. To avoid too hign temperature to distroy the resonance cavity because of too long marking time, cooling system and self-protector is used in the design.Existing laser-marking machines are mainly adopted immovable mode(laser light is not changed but the process flat is moved) or movable mode(laser light is changed but process flat not moved). Using the 2-dimension numerical control machining flat and dual galvanometer scanning system is to enlarge marking scope and to make up the shortcoming of slow marking velocity of immovable mode and deficiency of small marking scope of movable mode. This method is fit for the situation of larger scope , which improves produce efficiency.Based the format of plt file made by the CorelDRAW graph software. Pick-up vector position coordinate of the file, the imitate process is written in the soft, and edit the graph simply, such as move, rotate, zoom and portrait array. Transforming plt file into numeral control file, and appointing the file path is C://l.nc. Based the method of Visual C++ and OO program, laser marking interface is built, and file edit module and imitate module are encapsulated into the document class and view class respectivily, operation buttons are designed in the toolbar.Based PC, D/A convertor and 2-dimension galvanometer scanning system, lasermarking control system is built. Coordinate data scanned and kept in the computer are transformed into the analog signals by D/A converter, then control the galvanometer to deflexion. Control module is encapsulated into the control class. Because the time of statement is not coincident with the time of galvanometer's turning controled by voltage, delay is considered in the control process.Image coordinate and galvanometer pendular angle are kept in the computer according to the F9 field lens characteristic, enter pupil excursion and F6 characteristic error are ignored, that the image of laser scanning point move acceding to unlinearity relation is deduced theoretically. For deducing the distortion, error compensation is considered in the software.
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