Dual Ink Ejection Head Control for Color Reproducibility

Solution Overview

Problem

Conventional liquid ejecting devices face challenges in achieving uniform color reproduction due to manufacturing variations among ejection heads, making them unsuitable for high-color-reproducibility image printing.

Innovation Solution

The printing apparatus includes a first head and a second head, both capable of ejecting ink in the same color, supported by a carriage that is reciprocally movable. A control device selects one of the heads as active and sets an operation mode to either eject ink from both heads or only the active head, depending on the mode, to prevent color reproducibility issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple ejection heads are used to print over a wide range of the medium, then productivity is improved, but color reproduction uniformity deteriorates due to manufacturing variations among heads

Engineering Contradiction:

Improveprinting speedVSAvoidcolor reproduction uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The system dynamically switches between two operation modes: a first mode where both heads eject ink simultaneously for high-speed printing, and a second mode where only the head with better ejection properties ejects ink for high-quality printing. This dynamic adaptation allows the system to optimize between productivity and color reproduction uniformity based on the selected operation mode.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The control device changes the operational parameters of the ejection heads by selecting different operation modes. In the first mode, both heads operate at full capacity for maximum productivity. In the second mode, the system adjusts which head is active based on evaluated ejection properties, thereby changing the operational parameters to prioritize color reproduction uniformity over speed.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If both heads eject ink simultaneously to increase printing speed, then productivity is improved, but color reproducibility deteriorates due to individual differences among heads

Engineering Contradiction:

Improveprinting speedVSAvoidcolor reproducibility

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system dynamically switches between two operation modes: a first mode where both heads eject ink simultaneously for high-speed printing, and a second mode where only the head with better ejection properties ejects ink for high-quality printing. This dynamic adaptation allows the system to optimize between productivity and color reproduction uniformity based on the selected operation mode.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system creates a virtual copy of the printing function by having two separate ejection heads that can operate independently or together. By evaluating the ejection properties of each head and selectively using one or both, the system can replicate the desired printing quality while maintaining the option for high-speed dual-head operation when quality constraints are less critical.

Inventive Principle:

Principle #26Copying

3Manufacturing precision

If only one head is used to ensure uniform color reproduction, then color reproducibility is improved, but productivity decreases due to limited printing range per carriage movement

Engineering Contradiction:

Improvecolor reproduction uniformityVSAvoidprinting speed

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The system dynamically switches between two operation modes: a first mode where both heads eject ink simultaneously for high-speed printing, and a second mode where only the head with better ejection properties ejects ink for high-quality printing. This dynamic adaptation allows the system to optimize between productivity and color reproduction uniformity based on the selected operation mode.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system merges the printing functions of two separate ejection heads, allowing them to operate simultaneously in the first mode to cover a wider printing range and increase productivity. When color reproduction uniformity is prioritized, the system can still achieve single-head quality while maintaining the option for dual-head operation, effectively combining the strengths of both heads according to the selected operation mode.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS12240251B2Printing apparatus having first head and second head that eject ink in same color

Publication Date: 2025.03.04 BROTHER KOGYO KK

AI summary

A printing apparatus includes: first and second heads; a carriage; and a control device. The control device is configured to perform: (a) selecting; (b) setting; and (c) executing. The (a) selecting sets one of the first and second heads as an active head. The (b) setting sets an operation mode to one of a plurality of modes including first and second modes. The (c) executing executes a printing operation under the operation mode. The printing operation is performed by ejecting ink from both the first and second heads in a state where the first mode is set as the operation mode. The printing operation is performed by ejecting ink from the active head without ejecting ink from a non-active head in a state where the second mode is set as the operation mode. The non-active head is a head other than the active head among the first and second heads.