Image Processing Device Tone Value Adjustment for Inkjet Under-Refilling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet recording devices face an under-refilling phenomenon due to increased ink viscosity at low temperatures, leading to insufficient ink in liquid channels and potential breakdown of ink ejection, especially when the amount of ink ejected per unit time is high and the liquid channels are not filled promptly.
Innovation Solution
An image processing device that calculates and adjusts the tone values of multi-valued image data by aggregating pixels and reducing tone values for specific aggregations to prevent under-refilling, ensuring the ink ejected per ejection period is sufficient, thereby maintaining normal ink ejection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the amount of ink ejected per unit time is increased to enhance processing speed, then productivity is improved, but the under-refilling phenomenon occurs due to insufficient ink replenishment in liquid channels
Solution Approach 1:
The patent applies preliminary action by calculating the total tone values of pixels in advance and determining which aggregations require tone value reduction before the actual ink ejection process. This allows the system to pre-identify aggregations that would cause under-refilling and adjust their tone values beforehand, ensuring sufficient ink replenishment while maintaining high processing speed.
Solution Approach 2:
The patent changes the parameter of tone values for specific pixel aggregations that are identified as causing under-refilling. By reducing the tone values of these aggregations, the total ink ejection amount is controlled to match the liquid channel refilling capacity, thereby preventing the under-refilling phenomenon while maintaining high productivity.
2Reliability
If tone values are reduced during the quantization process to prevent under-refilling, then ink ejection stability is improved, but image quality deteriorates
Solution Approach 1:
The patent applies local quality by selectively reducing tone values only for specific pixel aggregations that are identified as causing under-refilling, rather than uniformly reducing tone values across the entire image. This localized adjustment prevents image quality deterioration in non-affected areas while ensuring ink ejection stability in problem areas.
Solution Approach 2:
The patent introduces an intermediary calculation and selection process that identifies which pixel aggregations require tone value reduction. This intermediary step acts as a mediator between the need for ink ejection stability and image quality preservation, ensuring that tone value reduction is applied only where necessary and in a controlled manner.
3Adaptability or versatility
If the quantization process is applied to reduce tones of input image data to match device capabilities, then device adaptability is improved, but the under-refilling phenomenon occurs due to large ink ejection amounts
Solution Approach 1:
The patent applies preliminary action by performing tone value reduction for specific aggregations before the quantization process. This preliminary adjustment ensures that the total ink ejection amount is controlled to match the liquid channel refilling capacity, preventing under-refilling while maintaining device adaptability through subsequent quantization.
Solution Approach 2:
The patent segments the image data into multiple pixel aggregations and identifies which segments require tone value reduction. By dividing the image into aggregations and selectively adjusting only those that would cause under-refilling, the system maintains device adaptability while preventing ink channel refilling issues.
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
This solution prevents the under-refilling phenomenon, ensuring consistent ink ejection and maintaining image quality by adjusting tone values before quantization, thus avoiding quality deterioration caused by reducing tone values during the quantization process.
Implementation Method 1
at low temperatures, when the flow resistance of ink is increased due to an increase in the viscosity of ink resulting from a temperature decrease or the like, the amount of ink that can be replenished in liquid channels per unit time is reduced
Data Source
AI summary
A calculator calculates a total value of tone values of all pixels in each aggregation by allocating each pixel of M-valued image data to one aggregation. Each block is either one of ejection-port groups including ejection ports having a common liquid channel serving as a liquid supply source or one of divided ejection-port groups. Each aggregation includes pixels of the M-valued image data corresponding to dots formed on a medium when liquid is ejected from ejection ports in one block during one L ejection period. Each L ejection period is obtained by dividing, by a plural number, a number of ejection cycles required to record an image on one recording medium. A tone-value reducer reduces tone values of at least part of pixels in an adjustment-requiring aggregation so that the total value becomes less than a threshold. A transmitter transmits the adjusted M-valued image data to a liquid ejecting device.