Inkjet Nozzle Correction by Image Tone to Prevent Broken Streaks
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Solution Overview
Problem
Existing inkjet recording technologies suffer from a reduction in image quality due to non-discharge correction being uniformly applied to defective nozzles, leading to new image defects such as broken streaks.
Innovation Solution
An inkjet recording apparatus that dynamically adjusts non-discharge correction based on the tone of the image information and the deviation of ink droplets, disabling defective nozzles and correcting adjacent nozzles as needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-discharge correction is always performed for defective nozzles, then image defects from defective nozzles are suppressed, but new image quality defects such as broken streaks occur
Solution Approach 1:
The patent applies dynamics by making the non-discharge correction function changeable based on image tone. The correction unit dynamically adjusts whether to perform correction on adjacent nozzles depending on the tone value of the image data. For high-tone images (70% or higher), the correction is suppressed to avoid creating broken streaks, while for lower-tone images, the correction is performed to maintain image quality.
Solution Approach 2:
The patent changes the parameter of correction application based on the tone value parameter of the image. By using the tone value (a numerical parameter representing image density) as a decision criterion, the system selectively applies non-discharge correction only when appropriate, thereby preventing the generation of broken streaks in high-tone regions while maintaining correction benefits in other regions.
2Reliability
If non-discharge correction is performed for all defective nozzles, then discharge abnormalities are corrected, but image quality deteriorates in high-tone regions
Solution Approach 1:
The patent applies local quality by making the correction approach different for different regions of the image based on tone value. High-tone regions (70% or higher) are treated differently from other regions - the former suppresses non-discharge correction to maintain image quality, while the latter applies correction to fix discharge abnormalities. This localized approach ensures optimal image quality across different tonal regions.
Solution Approach 2:
The system changes the correction behavior based on the tone value parameter. When the tone value exceeds the threshold of 70%, the correction unit changes from performing non-discharge correction to suppressing it, thereby adapting the correction strategy to the local image characteristics and preventing quality deterioration in high-tone regions.
3Reliability
If defective nozzles are disabled and adjacent nozzles are corrected, then non-uniformities from defective nozzles are reduced, but complexity of the correction system increases
Solution Approach 1:
The patent applies partial action by performing non-discharge correction only for certain cases rather than all defective nozzles. Instead of universally correcting all adjacent nozzles, the system selectively applies correction only when the tone value is below the threshold, thereby reducing unnecessary correction operations and simplifying the overall system complexity while maintaining image uniformity where it matters most.
Data Source
AI summary
An inkjet recording apparatus includes: plural nozzles that discharge ink droplets in accordance with image information to record an image on a recording medium; a detection unit that detects a defective nozzle from the plural nozzles; a non-discharge correction unit that performs non-discharge correction in which the defective nozzle detected by the detection unit is disabled from discharge and an amount of ink droplets from a nozzle that is adjacent to the defective nozzle is corrected; and a change unit that changes whether or not the non-discharge correction unit performs the non-discharge correction in accordance with a tone of the image information.