Inkjet Recording Apparatus Dual Phase Sensor Timing

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Solution Overview

Problem

Existing inkjet recording apparatuses face challenges in securing stable printing quality due to delays in phase sensor feedback and detection failures caused by ambient temperature changes and high-speed printing, leading to unreliable phase search results.

Innovation Solution

The apparatus employs a dual-phase sensor system, with a first electric charge detection section (phase sensor A) positioned between the electrification electrode and deflection electrodes for timely detection of ink particle charging, and a second electric charge detection section (phase sensor B) on the gutter to ensure accurate recovery, enhancing the reliability of phase search and stability of printing quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single phase sensor is positioned on the gutter to detect ink particle charging, then the detection is performed, but there is an interval between the electrification electrode and the gutter causing delayed feedback and unreliable phase search results

Engineering Contradiction:
Improvephase search reliabilityVSAvoidfeedback time delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The single phase sensor on the gutter is segmented into two separate detection sections: a first detection section positioned between the electrification electrode and deflection electrodes for early detection, and a second detection section positioned on the gutter for verification. This segmentation eliminates the time delay by placing the primary detection point closer to the electrification electrode while maintaining reliability through dual verification.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first electric charge detection section acts as an intermediary detection point between the electrification electrode and the traditional gutter-based sensor. This intermediary position allows earlier detection of ink particle charging while the second section on the gutter serves as a backup verification point, together providing timely and reliable phase search feedback.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the electric charge applied to ink particles is made extremely small to prevent them from flying over the gutter, then printing stability is maintained, but the phase sensor has difficulty detecting the amount of electric charge under the influence of ambient noises

Engineering Contradiction:
Improveprinting stabilityVSAvoidelectric charge detection precision
Core Design Contradiction:
Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The first electric charge detection section performs preliminary detection of the ink particles' electric charge immediately after electrification, before the particles reach the gutter. This early detection allows the system to identify and compensate for weak charge signals caused by small electric charge amounts, enabling accurate phase search even when printing stability requires minimal charging.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The detection system transitions from a single-point detection on the gutter to a two-dimensional detection approach with sensors positioned at different spatial locations (between electrode and deflection electrodes, and on the gutter). This multi-position detection enables the system to capture electric charge information from multiple perspectives, improving measurement precision for small charge amounts while maintaining printing stability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 allows for faster and more accurate detection of ink particle charging timing, improving the reliability of phase search results and maintaining stable printing quality even under varying conditions, such as temperature changes and high-speed printing.

Implementation Method 1

the ink particles are electrically charged by the electrification electrode

Methodology Applied
Scientific EffectElectrification: Electrostatic Induction

Implementation Method 2

deflection electrodes to make the electrically charged ink particles deflect by an electrostatic field

Methodology Applied
Scientific EffectElectrostatic field deflection: Electrostatics

Implementation Method 3

a phase sensor to perform phase search for detecting the optimum timing when the ink particles are electrically charged

Methodology Applied
Scientific EffectElectric charge detection: Electrostatics

Data Source

PatentEP3511166B1Inkjet recording apparatus
Publication Date: 2020.07.29 HITACHI IND EQUIP SYST CO LTD
  • EP3511166B1 patent drawingFigure 1
  • EP3511166B1 patent drawingFigure 2
  • EP3511166B1 patent drawingFigure 3(a)~3

AI summary

An inkjet recording apparatus, which can enhance the reliability of the phase search result to detect the optimal timing when the ink particles are electrically charged by the electrification electrode 11 and secure the stable printing quality, is provided. The inkjet recording apparatus 400 includes an ink receptacle 18 in which a printing ink for an object to be printed is received; a nozzle 8 which is connected to the ink receptacle 18 and from which the ink fed under pressure is discharged; an electrification electrode 11 to make ink particles discharged from the nozzle 8 electrically charged; an electrification signal generation unit to generate an electrification signal to make the electrification electrode 11 electrically charged; deflection electrodes 12 to make the ink particles electrically charged by the electrification electrode 11 deflect; a gutter 14 to recover the ink unused for the printing; and a control unit to control operations of the inkjet recording apparatus 400 as a whole; a first electric charge detection section 61 to detect an amount of electric charge in accordance with the electrically charged ink particles between the electrification electrode 11 and the deflection electrodes 12; and a second electric charge detection section 69 to detect an amount of electric charge of the ink flowing within the gutter 14.