Multi-Printhead Alignment Error Correction Using Test Patterns

The patent applies preliminary action by printing test patterns before actual production printing to measure and characterize alignment errors. The system prints test patterns at different locations across the printhead array, measures their positions using imaging devices, calculates alignment error maps, and stores these error characteristics for later compensation during production printing. This advance preparation enables the system to proactively correct alignment issues rather than reactively fixing them after artifacts appear.

The patent implements feedback by continuously measuring the actual positions of printed test patterns using imaging devices, comparing these measurements against expected positions, calculating alignment errors, and using these error measurements to adjust and compensate alignment in subsequent printing operations. The system creates a closed-loop control system where measurement information feeds back into the printing process to improve alignment accuracy and reduce artifacts.

The patent applies segmentation by dividing the printhead array into multiple discrete test pattern locations rather than treating it as a single unit. Test patterns are printed at specific locations including swath boundaries and overlap regions, allowing the system to measure and correct alignment errors independently at each location. This segmented approach enables targeted correction of location-specific alignment issues that would be missed by blanket correction methods.

The patent implements local quality by generating and applying location-specific alignment error maps for different regions of the printhead array. The system calculates separate error characteristics for test patterns printed at various locations, including edge regions and swath boundaries, and applies appropriate compensation for each location. This allows the system to address local alignment variations with precision tailored to each specific region's requirements.

The patent applies preliminary action by performing alignment measurements and creating error maps during initial calibration operations before production printing begins. The system captures alignment characteristics in advance, allowing production printing to proceed with pre-computed compensation parameters, thereby minimizing the time impact on overall production.

The patent implements self-service by enabling the printing system to automatically perform its own alignment measurements and corrections without requiring external intervention or specialized equipment. The printing system uses its own imaging devices and processing capabilities to measure alignment errors and generate correction parameters, reducing the need for additional external calibration operations and associated time losses.