| 摘要 |
In this laser pattern generator, plural laser beams (32) are arranged in a closely spaced, noninterfering array. The beams are concurrently deflected across a region of the target surface (30) by an acousto-optic deflector (28) driven by a swept frequency drive signal. The target is moved perpendicular to the direction of deflection to reposition it for exposure during the next stroke of the beams. The extent of target offset in the direction of deflection is measured and used to control initiation of modulation during each deflection stroke, so that each portion of the generated pattern begins from a uniform reference line on the target. Pattern data is supplied to the beams modulators (26) in accordance with data clock pulses the repetition rate of which is established by the rate of change of frequency of the deflector drive signal. |
