Configurable Error Hiding via Masking for Inkjet Nozzle Faults
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Solution Overview
Problem
Droplet deposition heads, such as inkjet printers, face issues with faulty nozzles that lead to defects in printed images due to missing or non-functional nozzles, affecting the overall quality of the image.
Innovation Solution
A masking technique is implemented to redistribute the droplets assigned to faulty nozzles among neighboring functioning nozzles, determining pixel color density and using a lookup table to select mask values for neighboring nozzles to ensure the required color density is achieved without exceeding their capacity, thereby compensating for faulty nozzles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a droplet deposition head with missing or non-functional nozzles is used, then the device can still operate, but the printed image quality deteriorates due to defects
Solution Approach 1:
A lookup table acts as an intermediary between the faulty nozzle and the neighboring nozzles, mapping the droplet requirements of faulty nozzles to appropriate neighboring nozzles that can compensate for the missing functionality while maintaining image quality
Solution Approach 2:
The system changes the operational parameters by dynamically adjusting which nozzles are activated based on their functionality status, using the lookup table to redirect droplet deposition tasks from faulty nozzles to functioning neighboring nozzles
2Manufacturing precision
If droplets are redistributed to neighboring nozzles to compensate for faulty nozzles, then image quality is maintained, but the complexity of the printing system increases due to the masking technique
Solution Approach 1:
The lookup table is pre-computed and stored before printing operations, containing all the redistribution mappings needed to compensate for faulty nozzles. This preliminary action eliminates the need for complex real-time calculations during printing, reducing operational complexity
Solution Approach 2:
The system uses a lookup table that stores pre-determined masking patterns, copying the appropriate mask values from the table during printing operations rather than calculating them dynamically, thereby simplifying the printing process
3Productivity
If the masking technique is configured for specific droplet deposition head characteristics, then printing efficiency is optimized, but the adaptability to different nozzle configurations is reduced
Solution Approach 1:
The lookup table is customized to reflect the specific characteristics and configuration of each droplet deposition head, creating locally optimized masking patterns that maximize printing efficiency for that particular device while accommodating its unique nozzle layout and functionality
Data Source
AI summary
Broadly speaking, embodiments of the present technique provide apparatus and methods to print an image using masking techniques that control the operation of a droplet deposition head having at least one faulty nozzle. More specifically, an image is analysed to determine a pixel colour density for each pixel of the image. A masking technique is provided which may distribute the droplets (or sub-droplets) that a faulty nozzle is assigned to print among one or more neighbouring, functioning nozzles.