Monitoring scan mirror motion in laser scanning arrangements

摘要

Contamination in a feedback signal is eliminated in a laser scanning arrangement having a drive coil driven by a drive signal formed as a periodic train of drive pulses to oscillate a scan mirror and a light beam reflected from the scan mirror. A feedback coil generates a feedback signal during oscillation of the scan mirror, the feedback coil being in proximity with the drive coil and being subject to corruption by cross-coupling between the coils. The drive coil is not driven with at least one drive pulse during a quiet time period. Cross-coupling is eliminated by generating the feedback signal only during the quiet time period, and by monitoring a position of the scan mirror by processing the feedback signal which was generated only during the quiet time period.