Ink-Jet Printer Density Correction for Multi-Path Printing
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Solution Overview
Problem
Existing ink-jet printers face density unevenness issues in multi-path printing due to variations in the amount of conveyance of the recording medium, as the correction of print data based on immediate ink density measurements may be improper before the ink is fully fixed on the medium.
Innovation Solution
The ink-jet printer system includes a density detector that moves with the ink-jet head to detect color density after the second ejecting operation, calculates an estimated density after ink fixation, and corrects print data based on the difference between the estimated and ideal densities, ensuring proper correction before the third ejecting operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the sensor detects color density immediately after ink attachment during printing, then the detection is performed without waiting for ink fixation, but the detected density does not accurately reflect the final fixed density leading to improper correction
Solution Approach 1:
The system performs preliminary detection of color density immediately after ink attachment, then uses this detection result to calculate an estimated final density after fixation. This estimated value is stored and used for correction in subsequent printing operations, allowing the system to proceed without waiting for actual ink fixation while maintaining measurement accuracy.
Solution Approach 2:
The system establishes a feedback loop where the detected initial density is used to estimate the final fixed density, which then feeds back into the correction process. The estimated density value is stored in memory and referenced during subsequent printing operations to determine appropriate corrections, creating a closed-loop system that continuously refines density compensation.
2Productivity
If multi-path printing is performed to improve printing coverage, then productivity increases, but density unevenness occurs due to variation in recording medium conveyance amount
Solution Approach 1:
The system uses the density detector to monitor actual color density during multi-path printing operations and feeds this information back to the controller. The controller then calculates density deviation from expected values and determines correction methods for subsequent printing operations, enabling real-time compensation for conveyance variations while maintaining high printing speed.
Solution Approach 2:
The system dynamically adjusts printing parameters based on detected density variations. By calculating the deviation between actual and expected density and determining appropriate correction methods, the system modifies subsequent ejection amounts or positioning parameters to compensate for conveyance variations, maintaining density uniformity across multi-pass printing operations.
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 effectively prevents density unevenness by accurately correcting print data based on estimated ink density after fixation, improving the quality of the printed image by accounting for the time it takes for ink to fix on the medium.
Implementation Method 1
an ink-jet head that moves in a scanning direction and ejects ink from a plurality of nozzles
Implementation Method 2
a density detector that moves with the ink-jet head in the scanning direction for detecting a color density which is a density of a color on a surface of the recording medium
Data Source
AI summary
An ink-jet printer, including a density detector and a controller, wherein, where successive three ejecting operations to be repeatedly performed on the same predetermined region of a recording medium are defined as first through third ejecting operations in the order of performance, the controller executes: a process for detecting a color density of the predetermined region immediately after attachment of the ink ejected in the second ejecting operation; a process for calculating, based on the detected color density, an estimated density after fixation of the ink ejected in the second ejecting operation; a process for calculating, based on print data, an ideal density after fixation of the ink ejected in the second ejecting operation; and a process for correcting the print data based on a difference between the estimated density and the ideal density, and wherein the ink-jet printer performs the third ejecting operation based on the corrected print data.