Print Head Nozzle Arrays with Anti-Flow Dots for Light-Streak Control
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Solution Overview
Problem
Existing printers experience density unevenness and light streaks due to misalignment of nozzle arrays discharging the same liquid, leading to issues like black and white streaks in print results.
Innovation Solution
A printing device and method that positions a first nozzle array upstream relative to a second nozzle array, with anti-flow dots formed at the boundary to merge liquids and suppress streaks by discharging anti-flow dots non-adjacently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If nozzle arrays are arranged to discharge the same liquid with overlapping portions, then printing coverage is improved, but light streaks and density unevenness occur due to misalignment
Solution Approach 1:
The nozzle array is divided into multiple sub-arrays (first nozzle array and second nozzle array) that are positioned at different locations. Each sub-array discharges liquid to specific regions, and by controlling the discharge timing and position, the patent avoids overlapping discharge zones that cause light streaks, while still achieving comprehensive coverage through the combined action of multiple sub-arrays
Solution Approach 2:
The control unit controls the discharge timing of each nozzle array in advance, ensuring that the first nozzle array discharges liquid to the first region before the second nozzle array discharges to the second region. This preliminary timing control prevents liquid from the first array from interfering with the second array's discharge, eliminating light streaks while maintaining continuous coverage
2Stability of the object's composition
If nozzle arrays are positioned to ensure continuous print regions, then printing continuity is improved, but light streaks appear at the boundary between regions
Solution Approach 1:
The control unit controls the discharge timing in advance, making the first nozzle array discharge liquid to the first region before the second nozzle array discharges to the adjacent region. This timing sequence ensures that liquid from the first array does not overlap with the second array's discharge zone, preventing light streaks at the boundary while maintaining continuous print coverage
Solution Approach 2:
The patent maintains continuous printing action by having multiple nozzle arrays discharge liquid to adjacent regions without interruption. The control unit coordinates the discharge timing so that as one array completes its region, the next array immediately discharges to the adjacent region, ensuring continuous coverage without creating light streaks through proper timing sequencing
Data Source
AI summary
A transfer unit relatively moves a medium in a relative movement direction intersecting a nozzle arrangement direction with reference to a print head. In an overlapping portion of the print head, a first nozzle array is positioned more upstream in the relative movement direction than a second nozzle array. in the nozzle arrangement direction, a boundary between a first print region by the first nozzle array and a second print region by the second nozzle array is within a range of the overlapping portion. A plurality of first nozzles include a normal nozzle present in the first print region, and an anti-flow dot forming nozzle present at an end portion at a side of the first print region in the second print region. A control unit causes the print head to form a plurality of anti-flow dots not adjacent to each other in the relative movement direction by a first liquid discharged from the anti-flow dot forming nozzle onto the medium during printing.