Staggered Printhead Roll and Stitch Error Correction
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Solution Overview
Problem
Staggered full width printhead assemblies in imaging devices face alignment challenges due to manufacturing tolerances, thermal expansion, and vibrations, leading to roll and stitch errors that affect image quality.
Innovation Solution
A method and system that evaluate image quality by generating positional correction data for printhead adjustments using test patterns, with a controller operating printhead actuators to correct roll and stitch displacements exceeding predetermined thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple printheads are arranged in a staggered full width array to increase printing rate, then productivity is improved, but alignment precision deteriorates due to manufacturing tolerances, thermal expansion, and vibrations causing roll and stitch errors
Solution Approach 1:
The system performs preliminary alignment by printing test patterns and evaluating image quality data before actual printing. The controller calculates correction values for roll and stitch errors and adjusts printhead positions in advance, ensuring precise alignment is established before production printing begins.
Solution Approach 2:
The system uses feedback from captured image data of printed test patterns to detect roll and stitch errors. The controller processes this feedback information, calculates correction values, and adjusts printhead positions accordingly, creating a closed-loop control system that continuously maintains alignment precision.
2Manufacturing precision
If printheads are adjusted to correct alignment errors, then image quality is improved, but device complexity increases due to additional actuators and control mechanisms
Solution Approach 1:
The controller serves multiple functions: it manages normal printing operations, evaluates image quality data, calculates alignment correction values, and controls actuators. This multi-functionality reduces the need for separate dedicated alignment control systems, thereby limiting the increase in device complexity.
Solution Approach 2:
The system performs self-alignment by automatically detecting its own alignment errors through test pattern evaluation and correcting them using integrated actuators. This self-service capability eliminates the need for external alignment equipment and manual adjustment procedures.
Data Source
AI summary
A method evaluates printhead position in a staggered full width array (SFWA) printhead assembly. The method includes selecting a first printhead configuration for printing a first test pattern on an image receiving member, generating positional correction data for roll and stitch displacements obtained from captured image data of the first test pattern, comparing the positional correction data to at least one threshold in a displacement range, and operating at least one printhead actuator in accordance with the positional correction data in response to the positional correction data exceeding at least one predetermined threshold in the displacement range.