Print Data Sub-Dot Editing for Peak-Current-Limited Thermal Printing
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Solution Overview
Problem
Conventional printing devices struggle to achieve both high printing quality and fast printing speed due to limitations in the current supplied to the thermal line head, resulting in faint start points of borders and other issues.
Innovation Solution
A print data editing device and method that edits print data by dividing dots into sub-dots in the sub-scanning direction, adjusting the timing of element energization, and optimizing the distribution of sub-dots across multiple lines to reduce peak current demand, thereby improving printing quality and speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the printing device supplies high current to the thermal line head to achieve fast printing speed, then printing speed is improved, but the peak current exceeds power supply limits
Solution Approach 1:
The patent divides a single line of print data into multiple sub-lines, where each sub-line contains a subset of the original elements. This segmentation allows the thermal line head to energize fewer elements simultaneously in each sub-line, reducing the peak current requirement while maintaining overall printing speed through sequential processing of sub-lines.
Solution Approach 2:
The patent dynamically adjusts the grouping of elements into sub-lines based on the power supply capabilities. By flexibly organizing elements across multiple sub-lines rather than fixing them in rigid rows, the system can adapt the current distribution to match power supply limits while still achieving fast printing through optimized sub-line sequencing.
2Power
If the printing device divides print data into even and odd positions to suppress peak current, then power consumption is controlled, but printing quality deteriorates due to faint start points
Solution Approach 1:
The patent applies different processing strategies to different regions within lines. By identifying start points of borders and other critical areas, the system can apply enhanced heating or extended duration specifically at these locations while using standard processing for other areas, thus maintaining overall power control while improving local printing quality.
Solution Approach 2:
The patent performs preliminary analysis of the print data to identify elements that require enhanced heating (such as start points of borders). Before actual printing, the system pre-processes this information to determine which sub-lines and elements need special attention, allowing targeted quality improvement without affecting the overall power consumption profile.
3Manufacturing precision
If the printing device energizes all elements in a line simultaneously to maintain printing quality, then printing quality is preserved, but the peak current exceeds power supply limits
Solution Approach 1:
The patent segments the set of elements in each line into multiple subsets organized as sub-lines. Each sub-line contains a manageable number of elements that can be energized simultaneously without exceeding power supply limits. The segmentation ensures that critical elements are distributed across different sub-lines rather than concentrated in a single high-current line.
Solution Approach 2:
The patent maintains continuous printing operation by processing sub-lines in sequence rather than stopping to recharge or reduce speed. Each sub-line is printed consecutively, ensuring that the thermal line head remains continuously active and productive while keeping instantaneous current draw within power supply capabilities.
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
The solution enhances printing quality while reducing the likelihood of peak current exceeding power supply limits, allowing for faster printing speeds compared to conventional methods.
Implementation Method 1
A conventional printing device uses a thermal line head provided with a plurality of heating elements to print on a print medium
Data Source
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AI summary
In a print data editing device, controller is configured to perform: editing; and converting. The editing edits print data representing an input image such that when sub-dots constituting the input image are compared by units of columns before and after performing the editing, a coincidence is maximized when an image of each column in the input image after the editing is the same position as an image of the corresponding column in the input image before the editing or is shifted by a corresponding shift amount in a sub-scanning direction relative to the image of the corresponding column in the input image before the editing. The converting includes: determining one or more sub-dot as a conversion sub-dot; and editing the print data such that the print data indicates OFF for the one or more sub-dots determined as the conversion sub-dot.