Inkjet Nozzle Malfunction Detection Using Overlapping Line Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet-type image forming apparatuses face challenges in accurately determining nozzle ejection malfunctions due to synchronization marks being improperly scanned when passing through gaps between adjacent sensor units of a line sensor, leading to inefficiencies in identifying defective nozzles.
Innovation Solution
The apparatus incorporates a line sensor with multiple sensor units that partially scan a test pattern image, including a synchronization mark, allowing for accurate determination of nozzle malfunctions by analyzing density distributions and utilizing overlapping scanning areas to ensure proper synchronization between the sensor units and nozzles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a line sensor with multiple sensor units is used to scan the test pattern image, then the scanning coverage and productivity are improved, but the synchronization mark may pass through gaps between adjacent sensor units causing improper scanning
Solution Approach 1:
The patent introduces an overlapping section dimension between adjacent sensor units in the scanning direction. By ensuring that scanning areas of adjacent sensor units overlap, the synchronization mark is captured in multiple sensor units simultaneously, eliminating gaps in detection coverage while maintaining high scanning speed.
2Reliability
If the synchronization mark is positioned to pass through the overlapping section of sensor units, then the reliability of synchronization mark detection is improved, but the test pattern image design becomes more complex
Solution Approach 1:
The patent applies different positioning strategies for different parts of the test pattern image. The synchronization mark is specifically positioned to pass through the overlapping section of adjacent sensor units, while other test pattern elements maintain their conventional positions. This localized adjustment ensures reliable synchronization mark detection without complicating the overall test pattern design.
Data Source
AI summary
An inkjet recording unit ejects ink to a sheet using plural nozzles. A line sensor scans a test pattern image printed on the sheet using the plural nozzles. The test pattern image includes a synchronization mark formed by a predetermined reference position nozzle. The line sensor includes plural sensor units that partially scan the test pattern image respectively and generate plural partial test pattern scanned images. Scanning areas of the sensor units have an overlapping section. The synchronization mark is formed so as to pass through the overlapping section. An ejection malfunction determination unit determines positions corresponding to a part of the plural nozzles in the partial test pattern scanned image on the basis of a position of the synchronization mark, and determines whether a nozzle corresponding to the determined position is an ejection malfunction nozzle or not on the basis of a density at the determined position.