Inkjet Printer Streak Prevention via Deformed Data Profiles
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Solution Overview
Problem
The streak-like phenomenon in the scanning direction of ink jet printers is caused by factors including paper transfer precision, mechanical errors, and nozzle positioning inaccuracies, leading to unsatisfactory ink discharge precision, especially at the ends of printing nozzles, resulting in visible streaks.
Innovation Solution
A printing method that deforms print data to create concave and convex parts at the end portions of the sub-scanning direction, setting the profile in an ambiguous state to prevent continuous dot arrays and mask or print dot information effectively, using a deformed data portion with an outside region for masking and an inside region for printing, and changing the printing rate to avoid continuous profile lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the printing head moves in the scanning direction and prints continuously, then productivity is improved, but manufacturing precision deteriorates due to streak formation
Solution Approach 1:
The patent divides the continuous printing process into discrete main scanning operations, where the printing head moves in the main scanning direction and deposits ink in segments. By controlling the printing head to perform multiple discrete scanning passes rather than continuous printing, the system maintains productivity while reducing streak formation caused by continuous ink discharge from multiple nozzles.
Solution Approach 2:
The patent implements periodic printing actions where the printing head performs repeated main scanning operations with controlled intervals. The printing head moves in the main scanning direction, discharges ink periodically at specific positions, and returns to the starting position. This periodic action pattern prevents continuous ink discharge that causes streaks while maintaining efficient productivity through systematic scanning cycles.
2Productivity
If multiple nozzles discharge ink in parallel, then productivity is improved, but manufacturing precision deteriorates due to positioning errors at end nozzles
Solution Approach 1:
The patent applies different control strategies to different nozzle positions. End nozzles (first and last nozzles in the array) are controlled to discharge ink only at specific main scanning positions, while intermediate nozzles operate with different timing. This local differentiation in nozzle control ensures that nozzles with positioning difficulties (end nozzles) do not create streaks, while maintaining overall printing productivity through coordinated operation of all nozzles.
Solution Approach 2:
The patent determines in advance which nozzles should discharge ink at which main scanning positions based on their positioning characteristics. Before actual printing, the control system identifies that end nozzles require restricted discharge timing to avoid streaks. This preliminary planning of nozzle discharge patterns allows the system to maintain productivity with multiple parallel nozzles while compensating for positioning errors at critical nozzle locations.
Data Source
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AI summary
The present invention is intended to prevent appearance of streaks in head scanning direction at the joint of print data of the image to be printed. Print data composed of a multiplicity of dot information is supplied to a printing head having a plurality of dot forming elements arrayed along a sub-scanning direction. The printing head and the printing medium relatively move in main scanning direction and sub-scanning direction each other, and an image is printed on the surface of the printing medium. In the print data supplied by every main scanning action of the printing head, a deformed data portion of concave and convex shapes of waveform are formed, for example, so that dots may not be arrayed in parallel continuously in the main scanning direction of the printing head, at the joint of the ends of the sub-scanning direction. The undulation profile of this waveform is set in an ambiguous state, and the ambiguous state of the profile is not a state of a continuous profile line when the printed profile is observed visually.