| 主权项 |
1. A method for coordinating beam axis position and beam axis velocity with laser emission at a constant laser pulse repetition rate, comprising:
generating a beam of laser pulses at a constant laser pulse repetition rate for propagation along an optical path from a laser; employing a fast positioner that is positioned along the optical path and operable for directing a beam axis of the optical path in a movement pattern over a workpiece, wherein the movement pattern includes directing the beam axis over noncutting areas on the workpiece and directing the beam axis at a beam axis velocity over a cutting path between start and end positions relative to the workpiece to deliver the laser pulses at the laser pulse repetition rate and at an irradiance to change a physical characteristic of the workpiece along the cutting path; employing a pulse-picking device to allow or prevent selected ones of the laser pulses from propagating along the optical path to the workpiece, wherein the laser pulses that are allowed to propagate to the workpiece are working laser pulses, and wherein the laser pulses that are prevented from propagating to the workpiece are nonworking laser pulses; employing a controller operable for receiving laser processing parameters for changing the physical characteristic of the workpiece and for providing control signals directly or indirectly to the laser, the beam-positioning system, and the pulse-picking device, wherein the laser processing parameters include or determine the laser pulse repetition rate, the cutting path, the beam axis velocity, and the irradiance; employing a timing device associated with the controller, wherein the timing device is operable to cause laser triggering signals to be sent to the laser triggering device at a constant repetition rate to cause the laser pulse repetition rate of the laser to be constant, thereby to cause emission of the laser pulses to be constant so that they exhibit stable and predictable pulse characteristics; and employing processing circuitry associated with the controller and operable for providing fast positioner control signals to the fast positioner to direct the beam axis to move along the cutting path over the workpiece; wherein, based on the laser pulse repetition rate, the processing circuitry is operable cause the beam axis to be directed to the start position relative to the workpiece and to be moving at the beam axis velocity when a first one of the working laser pulses impinges the workpiece; and wherein one or more pulse-picker signals gated through the timing device are operable to cause the pulse-picking device to prevent propagation of nonworking laser pulses over noncutting areas of the workpiece and to permit propagation of working laser pulses to impinge the workpiece over the cutting path including and between the start and end positions relative to the workpiece. |
