Inkjet Recording Device Ejection Timing Correction
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Solution Overview
Problem
Inkjet recording apparatuses face errors in ejection timing due to nozzle performance differences and uneven recording surfaces, leading to blurred images and poor quality, as existing methods struggle to accurately correct for deviations between the go and return paths.
Innovation Solution
A recording apparatus that records and reads test patterns with altered dot positions on both paths, using first and second test patterns with varying lengths to compute accurate ejection timing, ensuring ink is ejected at the same position on both paths, thereby correcting for deviations and improving image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single test pattern is recorded to determine correction values, then the correction process is simple, but accurate correction cannot be achieved when nozzles have different ejection characteristics
Solution Approach 1:
The test pattern is divided into multiple segments with different periodicities (first test pattern with longer period, second test pattern with shorter period). Each segment targets specific nozzle characteristics, allowing accurate measurement of correction values for nozzles with different ejection trajectories without requiring a single complex all-encompassing pattern.
Solution Approach 2:
Multiple test patterns are recorded beyond what a single pattern would provide. The first test pattern captures broad correction needs, while the second test pattern provides finer adjustment. This excessive action ensures that even nozzles with significantly different ejection characteristics can be accurately corrected.
2Reliability
If test patterns with different periodicities are recorded, then accurate correction for all nozzles can be achieved, but the recording process becomes more complex
Solution Approach 1:
The correction process is segmented into two stages: rough adjustment using the first test pattern with longer period, and fine adjustment using the second test pattern with shorter period. This segmentation makes the complex correction process manageable and reliable, as each stage addresses specific aspects of nozzle performance.
Solution Approach 2:
The first test pattern is recorded and processed before the second test pattern. The rough correction values obtained from the first pattern serve as a preliminary adjustment, which then enables accurate fine adjustment using the second pattern. This preliminary action simplifies the overall process by preparing the system for more precise measurement.
3Productivity
If ejection timing is not corrected, then the recording process is fast, but image quality deteriorates due to blurred images
Solution Approach 1:
Ejection timing correction is performed as a preliminary action before actual image recording. By pre-determining the correction values through test pattern analysis, the system can directly apply these corrections during normal operation, ensuring precise dot placement without slowing down the recording process.
Solution Approach 2:
The system performs self-diagnosis and self-correction by automatically analyzing test patterns and determining correction values. This self-service approach eliminates the need for manual adjustment while ensuring accurate dot placement, maintaining both productivity and manufacturing precision.
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 approach allows for precise correction of ejection timing, preventing image blurring and enhancing the quality of printed images by ensuring consistent dot placement on both the go and return paths.
Implementation Method 1
a sensor mounted on the carriage, for detecting a density of an image recorded on the recording medium
Data Source
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AI summary
When an inkjet printer ejects ink onto a recording medium on a go path and on a return path of a carriage, if ink cannot be ejected onto the same position on the go path and on the return path, image quality becomes poor. Test patterns with shifted ejection timing are hitherto recorded on the recording medium, and appropriate timing is input as a correction value. There is also an inkjet printer which automatically reads a test pattern, but the test pattern is recorded without consideration of a state of a head, and thus, accuracy is low. Therefore, a test pattern having a long period and a test pattern having a short period are recorded, and densities of the test patterns are read by a sensor. An extremum candidate is determined from the test pattern having a long period, and rough adjustment is made first. Then, in a region around the extremum, an extremum is determined from the test pattern having a short period. An extremum corresponding to a period to which the extrema of the two test patterns belong is set as a correction value. By determining ejection timing of the recording head using the correction value, an image in which dot deviation between the go path and the return path is inhibited can be recorded.