Inkjet Head Nozzle Malfunction Compensation via Adhesion Measurement
Solution Overview
Problem
Existing image forming apparatuses struggle to effectively correct deterioration in image quality due to malfunctioning recording elements, as previous techniques often fail to appropriately allocate data to maintain image quality.
Innovation Solution
The image forming apparatus includes a detector to measure the adhesion amount of ink in a peripheral region around a malfunctioning nozzle, a region setter to define an allocation region based on this measurement, and an allocator to redistribute dot data from the malfunctioning nozzle to normal nozzles within the allocation region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the number of recording elements is increased to achieve higher resolution and accuracy, then image quality is improved, but the number of malfunctioning recording elements increases, making image quality more likely to deteriorate
Solution Approach 1:
The invention changes the operational parameters of adjacent recording elements by increasing their ejection amounts to compensate for malfunctioning elements. This parameter adjustment allows the system to maintain image quality despite the increased probability of malfunction in higher-density recording element arrays.
Solution Approach 2:
The invention creates substitute dot data from adjacent normal recording elements to replace the function of malfunctioning recording elements. This copying approach allows the system to reconstruct the intended image output even when some recording elements fail, thereby maintaining overall image quality.
2Device complexity
If allocation data is distributed to positions separated from other dot data to simplify allocation, then device complexity is reduced, but image quality deterioration cannot be appropriately corrected
Solution Approach 1:
The invention applies different allocation strategies to different regions of the image based on local conditions. Specifically, it identifies malfunctioning recording elements and applies targeted compensation to adjacent regions, rather than using a uniform allocation approach. This local quality adjustment ensures that image quality is maintained in affected areas while keeping the overall system relatively simple.
3Measurement precision
If a wide peripheral region is secured to accurately calculate density for allocation data, then measurement precision is improved, but allocation data is allocated to positions separated from other dot data, causing image quality deterioration
Solution Approach 1:
The invention shifts the compensation approach from a two-dimensional density calculation over a wide peripheral region to a one-dimensional approach along the conveyance direction. By calculating adhesion amounts specifically in the conveyance direction and allocating compensation data within a limited range in this direction, the system achieves accurate compensation without separating allocation data from other dot data, thereby maintaining image quality.
Data Source
AI summary
An image forming apparatus includes: an image former that causes a head unit having a plurality of nozzles arranged in a row to eject a color material onto a recording medium conveyed in a conveyance direction to generate dots; a mover that relatively moves the recording medium and the head unit in a direction intersecting an arrangement direction of the plurality of nozzles in the head unit; a detector that detects a first adhesion amount of a color material in a first peripheral region around a nozzle-missing region corresponding to a malfunctioning nozzle; a region setter that sets an allocation region having an area corresponding to the first adhesion amount; and an allocator that allocates dot data corresponding to a malfunctioning nozzle to a normal nozzle in the allocation region.