Inkjet Head Gap Control via Optical Feedback for Density Uniformity
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Solution Overview
Problem
Existing liquid discharging devices, such as inkjet printers, face challenges in achieving sufficient image quality due to the inability to accurately set ink discharging timing based solely on the gap between the ink discharging surface and the paper conveyance surface, leading to issues with image density unevenness and wettability.
Innovation Solution
A liquid discharging device equipped with a carriage, a driving unit, a measuring unit, an image-capturing unit, and a setting unit that measures the distance between the carriage and the target, captures images, and adjusts the liquid discharging performance based on these measurements to improve ink droplet landing accuracy and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If ink discharging timing is set based solely on the gap between the ink discharging surface and the paper conveyance surface, then the device complexity is reduced, but the manufacturing precision of ink droplet landing position deteriorates
Solution Approach 1:
The patent employs feedback mechanisms by using image capturing units to detect the actual position of the paper and the gap distance, then adjusting the ink discharging timing based on this detected information. This closed-loop feedback system ensures precise ink droplet landing positions despite variations in paper conveyance or gap distance, directly resolving the contradiction between simplified control and positioning precision.
Solution Approach 2:
The patent replaces purely mechanical timing control (based on fixed gap measurements) with an optical detection system using image capturing units. This substitution allows for dynamic, real-time measurement of paper position and gap distance, enabling precise adjustment of ink discharging timing without increasing mechanical complexity, thus resolving the contradiction between device simplicity and positioning accuracy.
2Productivity
If the carriage reciprocates over a platen to discharge ink droplets, then the productivity is improved, but the manufacturing precision of image recording deteriorates due to gap variations
Solution Approach 1:
The patent implements dynamic adjustment of ink discharging timing based on real-time detection of gap distance and paper position. Instead of using fixed timing parameters, the system continuously adapts the discharging timing to match actual operating conditions, allowing high-speed carriage reciprocation while maintaining precise image recording accuracy despite gap variations.
Solution Approach 2:
The system uses feedback from image capturing units to detect paper position and gap distance during carriage reciprocation, then adjusts ink discharging timing accordingly. This real-time feedback mechanism enables the system to maintain high productivity through continuous carriage movement while ensuring consistent image recording accuracy despite dynamic gap variations.
3Ease of operation
If the gap between the ink discharging surface and the recording medium is not accurately controlled, then the ease of operation is improved, but the manufacturing precision of image density uniformity deteriorates
Solution Approach 1:
The system performs self-adjustment by automatically detecting the actual gap distance and paper position using image capturing units, then autonomously adjusting the ink discharging timing parameters. This self-service mechanism eliminates the need for manual gap calibration while ensuring uniform image density, resolving the contradiction between operational simplicity and recording precision.
Solution Approach 2:
The patent replaces manual mechanical gap adjustment with optical detection and automated control. Image capturing units detect gap distance and paper position, and the system automatically adjusts ink discharging timing based on this optical data, eliminating the need for precise mechanical gap control while maintaining uniform image density.
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
The solution enhances image quality by improving ink droplet landing precision and reducing image density unevenness, resulting in better solid area wettability and overall printing performance.
Implementation Method 1
a measuring unit configured to measure the distance between the carriage and the target
Implementation Method 2
an image-capturing unit configured to capture a target image
Data Source
AI summary
A liquid discharging device includes a carriage carrying a head configured to discharge a liquid onto a target, the liquid including an ink, the ink consisting water, an organic solvent, a coloring material, and a plurality of polysiloxane compounds, a driving unit configured to move the carriage and the target relatively to each other, a measuring unit configured to measure the distance between the carriage and the target, an image-capturing unit configured to capture a target image, and a setting unit configured to set a liquid discharging performance of the head based on a measurement result obtained by the measuring unit and the target image obtained by the image-capturing unit.