Inkjet Printer Nozzle Inspection via Low-Res Scanning and Interpolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet printing apparatuses face challenges in automatically detecting nozzle abnormalities, leading to image quality deterioration due to air entry or dust, which requires time-consuming manual inspection by users, especially for colors where visual inspection is difficult.
Innovation Solution
An inkjet printing apparatus with a recording head, scanner, interpolation processing part, and judgment part that reads a test pattern at a lower resolution, performs interpolation on the data, and compares it to ideal data to automatically detect nozzle abnormalities, including clogged, thin-line, and improper-droplet-path nozzles, using binarization and threshold settings for precise judgment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manual inspection by user is used to detect nozzle abnormalities, then inspection can be performed, but it takes considerable time and becomes an enormous burden on the user
Solution Approach 1:
The patent replaces the manual visual inspection mechanism with an automated optical scanning system. The scanner reads the test pattern printed on paper, and the control unit automatically analyzes the scanned data to detect nozzle abnormalities, eliminating the need for manual user inspection while maintaining detection reliability.
Solution Approach 2:
The patent creates a digital copy of the test pattern by scanning it with an optical scanner. This scanned copy is then processed by the control unit to automatically detect abnormalities, replacing the need for direct human visual inspection of the physical test pattern.
2Measurement precision
If reading the test pattern at the same resolution as the recording head, then high measurement precision is achieved, but the reading process becomes time-consuming
Solution Approach 1:
The patent applies partial action by reading the test pattern at a lower resolution than the full recording head resolution. The scanner reads at a resolution sufficient to detect nozzle abnormalities but lower than the maximum capability, achieving adequate measurement precision while significantly improving reading speed and productivity.
Solution Approach 2:
The patent changes the resolution parameter of the scanning process. Instead of using the full resolution of the recording head, the system adjusts the scanning resolution to an optimal level that balances measurement precision with reading speed, improving overall productivity without sacrificing detection accuracy.
3Productivity
If automatic detection system is implemented, then inspection speed is improved, but the system complexity increases
Solution Approach 1:
The patent makes the existing scanner and control unit perform multiple functions: the scanner is used for both normal printing operations and test pattern reading, while the control unit handles both printing control and abnormality detection analysis. This multi-functionality reduces the need for separate dedicated components, thereby limiting the increase in system complexity.
Solution Approach 2:
The patent merges the test pattern reading function with the existing printing system components. The scanner that is already part of the printing apparatus is utilized for reading test patterns, and the control unit that manages printing operations is also used for analyzing test pattern data to detect nozzle abnormalities, combining multiple functions into existing components.
4Reliability
If visual inspection is used for all ink colors, then comprehensive inspection is achieved, but it becomes difficult for certain ink colors where viewing by eyes is difficult
Solution Approach 1:
The patent replaces the human visual inspection system with an optical scanning system that can detect ink patterns objectively. The scanner uses light to read the test pattern and the control unit analyzes the reflected or transmitted light to detect abnormalities, eliminating the limitations of human vision for certain ink colors while maintaining comprehensive inspection reliability.
Solution Approach 2:
The patent uses optical scanning that can detect various ink colors through light reflection or transmission properties. The system can distinguish between different ink colors and detect abnormalities regardless of the specific color, overcoming the limitation where certain ink colors are difficult to view by the human eye.
Data Source
AI summary
A printing apparatus records a predetermined test pattern on printing paper, and reads the test pattern by means of a scanner. The scanner reads the test pattern at a resolution lower than the resolution of a recording head. This allows the automatic and fast reading of the test pattern. Additionally, the printing apparatus performs an interpolation process on read data, and judges whether there is an abnormality in nozzles or not, based on the read data subjected to the interpolation process. This reproduces the positions of and spacing between lines recorded on the printing paper with high accuracy to achieve the exact judgment as to whether there is an abnormality in the nozzles or not. Therefore, an inspection with a high degree of reliability is accomplished.