Inkjet Nozzle Timing Control to Prevent Droplet Interference

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Solution Overview

Problem

Existing liquid discharge apparatuses face issues with dot movement due to droplet interference, leading to increased ink consumption and reduced image quality, as they often correct dot size to prevent interference, which can result in inefficient droplet discharge and energy consumption.

Innovation Solution

A liquid discharge apparatus with multiple nozzle arrays discharging droplets of varying volumes at different times, controlled by a unit to prevent dot movement through staggered landing times, reducing interference without altering dot sizes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the dot size is corrected to a size larger by one level for dots that are highly likely to move from the landing position, then the movement of dots due to interference of droplets is prevented, but the amount of liquid consumed increases

Engineering Contradiction:
Improvedot position accuracyVSAvoidliquid consumption
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent applies dynamics by making the droplet discharge timing variable rather than fixed. Different nozzle arrays discharge droplets at different times based on their position and the likelihood of interference, allowing the system to adapt the discharge sequence dynamically to prevent dot movement while maintaining efficient liquid usage

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the timing parameter of droplet discharge for different nozzle arrays. By adjusting when each nozzle array discharges its droplets rather than changing dot size, the system prevents interference-induced dot movement while avoiding increased liquid consumption

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the dot size is corrected to prevent dot movement, then image quality is improved, but the amount of droplets to be discharged increases

Engineering Contradiction:
Improveimage qualityVSAvoidamount of droplets
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The system dynamically adjusts the discharge timing of different nozzle arrays based on real-time interference predictions, allowing precise control over droplet placement without increasing the total number of droplets discharged

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control unit predicts potential interference before droplets are discharged and pre-adjusts the discharge timing of affected nozzle arrays, preventing dot movement issues before they occur rather than correcting them after the fact

Inventive Principle:
Principle #10Preliminary action

3Productivity

If multiple nozzle arrays discharge droplets simultaneously, then productivity is improved, but dot movement due to droplet interference occurs

Engineering Contradiction:
Improvedischarge efficiencyVSAvoiddot position stability
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent implements dynamic timing control where nozzle arrays operate in a coordinated sequence rather than strict simultaneity. This allows high productivity to be maintained while preventing interference between adjacent droplets that would cause dot movement

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Different nozzle arrays discharge droplets at different times based on their specific position and the local interference risk. This localized timing adjustment prevents dot movement in critical areas while maintaining overall high discharge efficiency

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4434752B1Liquid discharge apparatus and liquid discharge method
Publication Date: 2026.01.14 RICOH CO LTD
  • EP4434752B1 patent drawingFigure 1
  • EP4434752B1 patent drawingFigure 2
  • EP4434752B1 patent drawingFigure 3

AI summary

A liquid discharge apparatus (1) includes a plurality of nozzle arrays (L1 to L4) and a control unit (400). The nozzle arrays (L1 to L4) discharge a plurality of droplets having different volumes onto a recording medium at mutually different times. The control unit (400) controls a discharge operation to discharge the droplets. The control unit (400) causes a nozzle array (L1) of the nozzle arrays to discharge a droplet, of the droplets, of a first reference amount, and causes another nozzle array (L4) of the nozzle arrays to discharge a droplet, of the droplets, of a second reference amount greater than the first reference amount to land later than the droplet of the first reference amount.