Printhead Autocorrection for Uneven Print Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Printers often produce uneven print density on media when the pressure applied by the printhead varies across the width or length, leading to inconsistent printing results, especially with labels that do not span the full width of the printhead and platen.
Innovation Solution
A system and method that identifies uneven pressure on print media by measuring its width relative to the printhead and platen, and compensates for it by varying the intensity of the contrast-inducing element, such as heat or ink, applied by the printhead to maintain consistent print density across the media.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the printhead applies pressure to the print media to ensure adequate contact, then the print density improves, but the pressure becomes uneven across the media width causing inconsistent print density
Solution Approach 1:
The patent applies local quality by varying the heat intensity at different locations across the printhead width. The control system adjusts the thermal energy applied to specific zones based on detected pressure variations, ensuring that areas with lower pressure receive more heat while areas with higher pressure receive less heat, thereby achieving uniform print density across the entire media width.
Solution Approach 2:
The patent changes the thermal parameter (heat intensity) dynamically across different spatial locations. By modulating the temperature or thermal energy applied at each printhead element based on pressure feedback, the system compensates for pressure non-uniformity and maintains consistent print quality throughout the media surface.
2Adaptability or versatility
If the label width is less than the full printhead width, then the printer can handle various media sizes, but the pressure distribution becomes uneven across the label
Solution Approach 1:
The patent applies preliminary action by measuring the media width before the printing process and pre-calculating the pressure distribution pattern. The control system uses this advance information to adjust the heat intensity profile across the printhead, compensating for expected pressure variations before printing begins, thereby ensuring uniform print density despite varying media widths.
Solution Approach 2:
The patent implements dynamics by making the heat intensity profile adjustable and adaptive rather than fixed. The system dynamically modifies the thermal parameters across different printhead zones based on the detected media width and pressure distribution, allowing optimal print quality for various media sizes while maintaining versatility.
3Manufacturing precision
If the printhead applies higher heat intensity to compensate for low pressure areas, then print density becomes consistent, but energy consumption increases
Solution Approach 1:
The patent applies local quality by directing increased energy only to specific zones where pressure is low, rather than uniformly increasing energy across the entire printhead. This targeted approach compensates for pressure non-uniformity while minimizing overall energy consumption by maintaining normal heat intensity in areas where pressure is already adequate.
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
Ensures consistent print density across the print media by adjusting the intensity of the applied contrast-inducing element based on pressure variations, preventing issues like excessively dark or light areas due to uneven pressure.
Implementation Method 1
the contrast-inducing element may be heat generated at points along the printhead, where the heat either (i) induces contrast on a heat-sensitive print media or (ii) melts ink from an ink ribbon on the print media
Data Source
AI summary
A printer may be used to print on print media, such as labels, where the print media, as fed through the print, spans substantially less than the full width of the printhead and platen. This may result in uneven print pressure across the print media during the print process. The uneven print pressure, in turn, may result in an uneven print density on the print media, which causes poor print quality. A system and method is employed with identifies the uneven print pressure, and compensates for the uneven print pressure to ensure consistent print density and good print quality. Along segments of the printhead which apply a below average pressure to the print media, the printhead is configured to apply a proportionately higher density of an appropriate contrast-inducing element, such as ink or heat. Along segments of the printhead which apply an above average pressure to the print media, the printhead is configured to apply a proportionately lower density of an appropriate contrast-inducing element, such as ink or heat.