Inkjet Printer Skew Correction via Data Shifting
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Solution Overview
Problem
Conventional printing methods with inkjet printing apparatuses fail to prevent dot deviation in the direction orthogonal to the transport direction, leading to degradation in image quality due to skew in the printing medium, affecting both within and between printing heads.
Innovation Solution
A data processing method that detects the skew of the printing medium and generates correction print data to shift print data from the printing unit in the direction orthogonal to the paper-feed direction, ensuring proper alignment and preventing dot deviation between printing heads by selecting alternative printing sections based on the skew angle and direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional printing methods are used with printing heads spaced away for each color, then multi-color printing can be performed, but dot deviation occurs in the direction orthogonal to the transport direction when the printing medium is skewed
Solution Approach 1:
The system performs preliminary skew detection on the printing medium before printing, and pre-calculates the necessary data shifting amounts for each printing head based on the detected skew. This allows the printing data to be corrected in advance, compensating for the skewed medium and preventing dot deviation among the spaced printing heads.
Solution Approach 2:
The patent applies different data shifting amounts to different printing heads based on their individual positions and the detected skew. Each printing head's data is locally adjusted according to its specific requirements, allowing precise compensation for skew-induced dot deviation while maintaining the multi-color printing capability.
2Ease of operation
If printing data is not corrected for skew, then printing process is simple, but dot deviation degrades image quality
Solution Approach 1:
The system automatically detects skew and performs data shifting corrections without requiring manual intervention. The printing apparatus self-adjusts the printing data based on detected skew conditions, maintaining high image quality while keeping the operation simple and automated.
Solution Approach 2:
The system uses skew detection feedback to dynamically adjust printing data. The detected skew information feeds back into the data processing system, which automatically calculates and applies the appropriate shifting corrections, creating a closed-loop system that maintains image quality without complex manual operations.
3Manufacturing precision
If skew detection and data correction are implemented, then dot deviation is prevented, but processing complexity increases
Solution Approach 1:
The patent divides the correction process into separate handling for each printing head, calculating data shifting amounts individually based on each head's position and the detected skew. This segmentation allows the complex correction to be broken down into manageable, position-specific calculations that can be efficiently processed.
Solution Approach 2:
The system changes the parameters of printing data (shifting amounts in the paper-feed direction) based on the detected skew angle and printing head positions. By dynamically adjusting these parameters, the system achieves precise dot alignment correction through mathematical transformations rather than complex mechanical adjustments.
Data Source
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AI summary
Provided is a data processing method of a printing apparatus for printing a multi-color image on a printing medium by each of printing heads for at least two colors while transporting the printing medium relative to the printing heads in a paper-feed direction. The method includes a skew detecting step of detecting a degree of skew of the printing medium; a correction printing-data generating step of shifting print data from a printing unit for performing printing in a direction orthogonal to the paper-feed direction in accordance with the degree of skew to generate correction printing-data, the printing unit having a first printing head disposed upstream in the paper-feed direction and a second printing head spaced away from the first printing head downstream in the paper-feed direction; and a printing step of performing printing on the printing medium with the printing unit in accordance with the correction printing-data.