Ink Jet Recording Head Pigment Specific Gravity Control
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Solution Overview
Problem
Ink jet recording methods with recording heads inclined relative to the gravity direction face insufficient color mixing recoverability due to ink mixing and adherence issues, leading to uneven pigment distribution and reduced image quality.
Innovation Solution
The method involves using a recording head with adjacent ejection orifice arrays for different inks, where the true specific gravity of the pigment in one ink is smaller than in another, ensuring the pigment with lower specific gravity remains near the meniscus and the ink with higher specific gravity is ejected effectively, thereby improving color mixing recoverability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a recording head with multiple ejection orifice arrays is used to eject multiple inks, then the productivity and miniaturization of the ink jet recording apparatus are improved, but the color mixing recoverability deteriorates due to ink mixing
Solution Approach 1:
The patent changes the physical parameter of specific gravity difference between pigments to control ink ejection behavior. By selecting pigments with different specific gravities for different inks, the system achieves natural separation of ink streams during ejection, preventing color mixing while maintaining high productivity with multiple ejection orifice arrays
Solution Approach 2:
The patent segments the ejection process by using separate ejection orifice arrays for different inks (first ejection orifice array for first ink, second ejection orifice array for second ink). This segmentation prevents mixing at the source while maintaining the ability to eject multiple inks simultaneously for high productivity
2Length of moving object
If the ejection orifice surface is inclined with respect to the direction of gravity, then the conveying distance of the recording medium is shortened, but the pigment distribution becomes uneven due to adherence and mixing issues
Solution Approach 1:
The patent uses specific gravity difference as a controlling parameter to counteract the adverse effects of the inclined ejection orifice surface. The pigment with smaller specific gravity naturally rises to the meniscus position even on an inclined surface, ensuring uniform pigment distribution and preventing adherence issues regardless of the inclination angle
Solution Approach 2:
The patent employs the buoyancy force (anti-weight effect) on pigments with different specific gravities to counteract the gravitational adherence caused by the inclined ejection orifice surface. The lighter pigment (smaller specific gravity) is naturally pushed upward to the meniscus, compensating for the inclination-induced pigment migration
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 configuration enhances color mixing recoverability by preventing pigment diffusion and adherence, maintaining image quality even after repeated recording and storage, reducing waste ink and improving the overall performance of the ink jet recording process.
Implementation Method 1
a true specific gravity of a pigment in the first ink is smaller than a true specific gravity of a pigment in the second ink
Implementation Method 2
a recording step of ejecting the aqueous ink from the recording head disposed so that an angle formed between the ejection orifice surface of the recording head and the direction of gravity is 0° or more to less than 90° to record an image on the recording medium
Data Source
AI summary
The ink jet recording method, which uses an ink jet recording apparatus, including: a first ink and a second ink containing a pigment; and a recording head having an ejection orifice surface in which a first ejection orifice array for ejecting the first ink and a second ejection orifice array for ejecting the second ink are formed, wherein the first ejection orifice array and the second ejection orifice array are sequentially arranged from the bottom in the direction of gravity to be adjacent to each other and arranged to at least partially overlap each other, includes: a recording step, wherein a true specific gravity of the pigment in the first ink is smaller than a true specific gravity of the pigment in the second ink.