Liquid Discharge Nozzle Detection Using Variable Pattern Images
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid discharge apparatuses, such as inkjet printers, face challenges in efficiently detecting and addressing non-discharge nozzles, leading to abnormal print images like white stripes, due to limitations in detecting defective nozzles without disrupting the printing process.
Innovation Solution
A liquid discharge apparatus and method that includes a liquid discharge head, scanning device, conveyance device, reading device, and control circuitry, which changes detection pattern images based on the target object's feed amount in the sub-scanning direction, allowing for efficient identification of defective nozzles using a two-dimensional image sensor and sensor controller, enabling compensation and recovery operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a reading device is used to detect non-discharge nozzles by reading printed patterns, then defective nozzles can be identified, but the detection process requires additional scanning time and may disrupt the printing workflow
Solution Approach 1:
The system performs preliminary detection of defective nozzles by reading printed patterns before actual printing operations. The control circuitry identifies non-discharge nozzles in advance, stores their positions, and uses this information to compensate during subsequent printing, eliminating the need for repeated detection scans and reducing overall scanning time
Solution Approach 2:
The system uses a two-dimensional image sensor to capture optical images of printed nozzle-check patterns, creating a digital copy of the nozzle discharge status. This optical copying method enables rapid, non-contact detection of defective nozzles without physical interference with the printing process, reducing detection time while maintaining accuracy
2Measurement precision
If traditional nozzle detection methods are used, then defective nozzles can be identified, but the apparatus requires complex scanning mechanisms and larger sensors
Solution Approach 1:
The system transitions from one-dimensional line sensor detection to two-dimensional image sensor detection. The 2D sensor captures the entire nozzle-check pattern in a single frame, eliminating the need for complex mechanical scanning mechanisms. This dimensional change simplifies the device structure while maintaining or improving detection precision through the ability to analyze the complete pattern simultaneously
Solution Approach 2:
The system replaces mechanical scanning mechanisms with an optical imaging system. Instead of using moving parts to scan across the printed pattern, a stationary two-dimensional image sensor captures the entire pattern optically. This substitution eliminates mechanical complexity while achieving precise nozzle defect detection through image processing
3Reliability
If comprehensive nozzle detection is performed across the entire printing area, then all defective nozzles are detected, but the detection process becomes time-consuming and reduces productivity
Solution Approach 1:
The system performs comprehensive nozzle detection in advance during initialization or maintenance modes, storing the results for use during normal printing operations. This preliminary comprehensive check ensures all defective nozzles are identified without impacting subsequent printing productivity, as the detection data is reused for compensation during actual printing
Solution Approach 2:
The system maintains continuous printing operations while using stored detection data for real-time compensation. Once nozzles are detected and their positions stored, the control circuitry continuously applies compensation algorithms during printing without interrupting the printing workflow, maintaining productivity while ensuring quality through ongoing use of detection results
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 enables efficient detection and compensation of defective nozzles, preventing abnormal print images and reducing unnecessary scanning, thus improving print quality and reducing costs by using a compact two-dimensional image sensor.
Implementation Method 1
a reading device disposed at a predetermined position with respect to the liquid discharge head... reading the detection pattern image with a reading device
Data Source
AI summary
A liquid discharge apparatus includes a liquid discharge head, a scanning device, a conveyance device, a reading device, control circuitry, and a detecting device. The liquid discharge head is configured to discharge liquid to a target object. The scanning device is configured to move the liquid discharge head in a main scanning direction. The conveyance device is configured to convey the target object in a direction perpendicular to the main scanning direction. The reading device is disposed at a predetermined position with respect to the liquid discharge head. The control circuitry is configured to change a detection pattern image for detecting a defective nozzle, in accordance with a feed amount of the target object in the sub-scanning direction. The detecting device is configured to identify a nozzle corresponding to a defective portion of the detection pattern image read by the reading device.