Barcode Reader Jitter Correction via Marking Signal

A marking signal generated by a marking on the polygon mirror wheel serves as an intermediary reference to eliminate jitter. The marking signal provides a stable, tolerance-independent reference point that mediates between the variable mirror surface positions and the required precise scan timing, allowing accurate synchronization without being affected by mirror surface variations.

The patent replaces the mechanical/tolerance-based trigger signal generation with an optical/electronic marking signal system. Instead of relying on the physical position and tolerance variations of mirror surfaces to generate triggers, the system uses a marking on the rotating wheel detected by a sensor, substituting the mechanical positioning problem with an optical detection solution that provides precise, tolerance-independent timing references.

The marking signal provides continuous feedback about the precise angular position of the polygon mirror wheel during rotation. This feedback is used to dynamically adjust and synchronize scan timing across multiple scans, ensuring that even when barcodes span multiple scans, the timing information remains accurate and can be correctly assembled without jitter-induced errors.

The marking signal is used to pre-establish accurate timing references before barcode detection begins. By synchronizing scan start times relative to the marking signal position, the system prepares precise temporal markers in advance, ensuring that subsequent barcode scans across multiple periods can be accurately aligned and assembled even when the barcode extends across scan boundaries.