Liquid Ejection Position Correction for Dot Interval Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet recording apparatuses face challenges in maintaining image quality due to ink ejection position shifts, leading to dot interval unevenness when forming color images with multiple liquid ejection units, as the relative position of the liquid ejection units with respect to the print sheet can change during image formation.
Innovation Solution
A position correction apparatus that includes a position detection unit, a moving unit, a moving amount determination unit, a moving speed determination unit, and a move control unit to accurately adjust the liquid ejection unit's position based on the conveyed object's position and conveyance speed, ensuring consistent dot intervals across the print sheet.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the liquid ejection unit is moved in the width direction according to print sheet edge position, then position correction is achieved, but dot interval unevenness occurs due to nozzle separation in the conveyance direction
Solution Approach 1:
The patent applies dynamics by making the liquid ejection unit movable in the width direction through a moving unit, allowing real-time position adjustment based on detected print sheet edge positions. This dynamic positioning capability enables the system to adapt to position variations while maintaining dot interval uniformity through coordinated control of multiple nozzles.
Solution Approach 2:
The patent implements feedback control by using a position detection unit to continuously monitor the print sheet edge position and feed this information back to the control unit. The control unit then adjusts the moving unit to correct position deviations, creating a closed-loop control system that maintains both position accuracy and dot interval uniformity.
2Measurement precision
If multiple nozzles are arranged in the width direction to increase density, then image resolution is improved, but dot interval unevenness increases due to nozzle separation in the conveyance direction
Solution Approach 1:
The patent applies segmentation by dividing the imaging function across multiple nozzles arranged in the width direction. Each nozzle contributes to forming the complete image, allowing increased nozzle density for higher resolution while the control unit coordinates their operation to maintain uniform dot intervals despite separation in the conveyance direction.
Solution Approach 2:
The patent addresses the dot interval issue by introducing movement in the width direction (another dimension) to compensate for the separation in the conveyance direction. The liquid ejection unit moves dynamically in the width direction to ensure that dots from separated nozzles align properly on the print sheet, maintaining uniformity across the width dimension.
Data Source
AI summary
A position correction apparatus that corrects a position of a liquid ejection unit ejecting liquid toward a conveyed object includes a position detection unit configured to detect a position of the conveyed object in a width direction of the conveyed object, a moving unit configured to move the liquid ejection unit in the width direction, a moving amount determination unit configured to determine a moving amount of the liquid ejection unit in the width direction based on a position of the conveyed object in the width direction, a moving speed determination unit configured to determine a moving speed of the liquid ejection unit in accordance with a conveyance speed of the conveyed object, and a move control unit configured to control the moving unit so as to move the liquid ejection unit at the moving speed and by the moving amount in the width direction.