Inkjet Recording Device Gray Head Positioning
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Solution Overview
Problem
Inkjet recording devices with multiple ink ejecting portions experience color shifts due to positional displacement of the recording medium, leading to deterioration in image quality, especially when the distance between ink ejecting portions increases, affecting the mixing of gray ink with primary colors.
Innovation Solution
The inkjet recording device optimizes the arrangement of head units to minimize the distance between ink ejecting portions, particularly placing the gray ink head unit within the arrangement range of primary-color head units and positioning special color head units outside this range to maintain accurate color mixing and reduce positional displacement impacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of ink ejecting portions is increased to improve color reproducibility, then color mixing capability is improved, but the distance between ink ejecting portions increases causing positional displacement and color shift
Solution Approach 1:
The patent introduces a new spatial dimension by arranging ink ejecting portions not only in the conveying direction but also in the width direction. Specifically, the gray ink ejecting portion is positioned at a location different in the width direction from the primary color ink ejecting portions, creating a two-dimensional arrangement that reduces the linear distance impact while maintaining color mixing capability.
Solution Approach 2:
The patent applies local quality by positioning the gray ink ejecting portion at a specific location within the arrangement range of primary color ink ejecting portions, rather than uniformly distributing all ejecting portions. This localized positioning ensures that gray ink can still mix properly with primary colors at the target position while minimizing overall distance-related displacement issues.
2Adaptability or versatility
If the distance between ink ejecting portions is increased to accommodate more colors, then color variety is improved, but color mixing accuracy deteriorates due to positional displacement
Solution Approach 1:
By utilizing the width direction as an additional spatial dimension for positioning ink ejecting portions, the system can accommodate more color types without linearly increasing the distance in the conveying direction. The gray ink ejecting portion is placed at a width-direction offset that allows it to eject ink that will converge with primary color inks at the recording position, thus maintaining mixing accuracy while expanding color variety.
Solution Approach 2:
The patent uses the spatial arrangement in the width direction as an intermediary mechanism to decouple the relationship between distance and mixing accuracy. By positioning the gray ink ejecting portion laterally rather than linearly, the system creates an intermediate positioning strategy that allows greater color variety while preventing direct proportional increase in displacement errors.
3Adaptability or versatility
If multiple ink ejecting portions are positioned at different locations, then color coverage is improved, but positional displacement of recording medium causes color shift
Solution Approach 1:
The patent implements local quality by strategically positioning the gray ink ejecting portion within the arrangement range of primary color ink ejecting portions rather than distributing it uniformly. This localized placement ensures that even with positional displacement of the recording medium, the gray ink and primary color inks maintain sufficient spatial overlap to achieve accurate color mixing and prevent color shift.
Solution Approach 2:
By introducing width-direction positioning for the gray ink ejecting portion, the system expands color coverage without linearly increasing vulnerability to displacement in the conveying direction. The lateral offset creates a geometric relationship that reduces the impact of conveying-direction displacement on color mixing accuracy.
Data Source
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AI summary
An inkjet recording device which is capable of recording an image including a portion in which at least one color in three primary colors is mixed with gray on a recording medium by using inks in the three primary colors (yellow, magenta, cyan), black, and gray includes five ink ejecting portions which eject ink in one color of yellow, magenta, cyan, black and gray, respectively, to the recording medium conveyed by a conveyer, the five ink ejecting portions are provided at different positions with respect to a conveying direction of the recording medium by the conveyer, and the gray ink ejecting portion ejecting the ink in gray in the five ink ejecting portions is disposed inside an arrangement range of a primary-color ink ejecting portion group consisting of three ink ejecting portions which eject ink in the three primary colors in the five ink ejecting portions with respect to the conveying direction.