Patent ID: 7583417

Claim:
A bi-directional imaging apparatus comprising: a light source for generating a light beam; a scanner for scanning the light beam through a scan path in a forward direction for a forward scan duration and a reverse direction for a reverse scan duration; first and second sensors disposed in the scan path for sensing the light beam as it scans across the sensors to produce first and second sensor signals corresponding respectively to the light beam scanning across the first and second sensors; control logic for receiving the first and second sensor signals and determining first and second scan durations based on the first and second sensor signals, and producing first and second control signals corresponding to the first and second scan durations, wherein scan duration is a time period corresponding to the first and second sensor signals; a drive signal generator for receiving the first and second control signals, producing first and second drive signals and sending the first and second drive signals to the scanner to substantially equalize the forward scan duration with the reverse scan duration.