Print Pattern Alignment Using Optical Register Marks
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Solution Overview
Problem
Existing printing technologies face challenges in accurately aligning color planes on a print medium, leading to noticeable print quality issues due to misalignment, and result in waste from register marks that are cut after printing.
Innovation Solution
A method for aligning print patterns using optical detection units and adjustable printing rollers and skewing rollers to adjust horizontal, vertical, and skewing misalignments, with reduced-width register marks on one edge region to minimize waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If register marks are printed on both lateral edge regions to facilitate alignment control, then alignment precision is improved, but material waste increases due to larger trimmed areas
Solution Approach 1:
The patent applies different register mark widths at different lateral positions: the first register mark at the first lateral edge has a larger width for robust detection, while the second register mark at the second lateral edge has a reduced width. This local differentiation optimizes alignment control at each position while minimizing overall material waste, as the reduced width at the second edge reduces the trimmed area without compromising alignment precision.
2Loss of substance
If the width of register marks on the second lateral edge is reduced to minimize waste, then material waste is reduced, but detection reliability may deteriorate
Solution Approach 1:
The patent performs preliminary alignment adjustment using the first register mark at the first lateral edge before printing the second register mark. The horizontal register is adjusted based on the position of the first register mark, which preliminarily defines the horizontal position. This preliminary action ensures that even the reduced-width second register mark will be reliably detected, as its position is already well-defined by the prior adjustment.
3Manufacturing precision
If the horizontal register is adjusted based on the first register mark position, then alignment precision is improved, but the complexity of the adjustment process increases
Solution Approach 1:
The patent employs an optical detection unit that detects the position of the first register mark and provides feedback for horizontal register adjustment. The detection unit measures the actual position of the first register mark, compares it with the desired position, and this feedback information is used to adjust the horizontal register. This closed-loop feedback mechanism achieves high alignment precision through a systematic but manageable adjustment process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Achieves high-accuracy alignment of color planes, reducing waste by optimizing register mark placement and size, ensuring precise print quality without additional material loss.
Implementation Method 1
determining the horizontal and vertical position of the first register mark at the first lateral edge region using the detection unit
Data Source
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AI summary
A method for aligning a print pattern on a print medium (30) in a printing device (10) with at least a first printing unit (16) and a second printing unit (18), wherein each printing unit (16, 18) comprises a printing roller (24, 25) and wherein the second printing unit (18) comprises an optical detection unit (26), wherein the print 5 medium (30) comprises a first lateral edge region (35) and a second lateral edge region (37) opposed to the first lateral edge region (35) and travels along a longitudinal direction from the first printing unit (16) to the second printing unit (18). One method step comprises printing a first register mark (38) on the first lateral edge region (35) and a second register mark (40) on the second lateral edge region10 (37) being opposed to the first lateral edge region (35) of the print medium (30) by a first printing unit (16). A further method step comprises determining the horizontal and vertical position of the first register mark (38) at the first lateral edge region (35) using the detection unit (26) and adjusting a vertical and/or horizontal register based on the position of the first register mark (38). Another method step 15 comprises, after adjusting the vertical and/or horizontal register based on the position of the first register mark (38), printing a third register mark (46) on the first lateral edge region (35) and a fourth register mark (48) on the second lateral edge region (37) of the print medium (30) by the second printing unit (18). The maximum width of the second and fourth register marks (40, 48) on the second lateral edge 20 region (37) is smaller than the maximum width of the first and third register marks (38, 46) on the first lateral edge region (35). Moreover, a printing device (10) is provided.