Serial Printer Edge Pixel Brightness Control for Banding Reduction
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Solution Overview
Problem
Existing printing technologies face challenges in maintaining accurate ink droplet landing positions due to environmental changes, mechanical inaccuracies, and medium variations, leading to visible banding unevenness, especially when printing geometric patterns with ultrafine lines.
Innovation Solution
A printing method that employs multiple pass operations with varying brightness levels for edge pixels, using a Gaussian filter or edge pixel deletion to enhance the brightness of the second pass operation, thereby reducing the visibility of positional displacement and banding unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple pass operations are used to print line images, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The printing process is divided into multiple pass operations, where each pass prints specific regions (edge pixels or non-edge pixels) of the line image. This segmentation allows precise control over different parts of the image, improving landing position accuracy by addressing displacement issues in specific regions without requiring complete re-printing of the entire image.
Solution Approach 2:
The patent applies preliminary actions by using a Gaussian filter or edge pixel deletion before printing to identify and mark edge pixels. This preprocessing step enables the system to anticipate which regions require special handling in subsequent pass operations, thereby improving precision without adding complex real-time adjustments during printing.
2Manufacturing precision
If correction values are set for discharge timing, then manufacturing precision is improved, but adaptability deteriorates
Solution Approach 1:
Instead of using fixed correction values, the patent dynamically determines printing strategies based on real-time detection of edge pixels and actual printing conditions. The system adapts its approach by selectively applying different pass operations to different regions of the image, allowing it to respond to environmental changes, mechanical variations, and medium differences without requiring manual re-calibration of correction values.
3Object-affected harmful factors
If brightness of second printing is increased, then object-affected harmful factors are reduced, but use of energy increases
Solution Approach 1:
The patent applies local quality by increasing brightness only in specific regions where it is most needed - namely, in regions affected by landing position displacement and banding unevenness. Rather than uniformly increasing brightness across the entire image, the system selectively enhances brightness in problematic areas, thereby reducing visible defects while minimizing additional energy consumption compared to full-image brightness enhancement.
Data Source
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AI summary
Provided is a printing method for performing printing using a serial printer. In printing of a print image including a line image, the printing method includes a raster line forming step of forming each of raster lines configuring the image, by a plurality of pass operations. In the formation of each of the raster lines, when printing of a region corresponding to edge pixels of the line image by a first pass operation, which is one of the plurality of pass operations, is first printing, and printing of the region corresponding to the edge pixels by a second pass operation that is different from the first pass operation, of the plurality of pass operations, is second printing, a brightness of the printing by the second printing is higher than a brightness of the printing by the first printing.