Liquid Jet Head Drive Board Layout for Stable Nozzle Waveforms

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing liquid jet recording devices face challenges in improving print quality due to variations in wiring impedance and drive waveform characteristics, leading to degraded printing performance.

Innovation Solution

The implementation of a drive board with a flexible substrate that includes a plurality of ground terminals and power-supply terminals arranged at multiple positions along the longitudinal direction, coupled to constant-potential wiring lines, and decoupling capacitors to minimize wiring impedance and stabilize drive signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional wiring layout is used, then device complexity is reduced, but wiring impedance variation increases leading to degraded print quality

Engineering Contradiction:
Improveprint qualityVSAvoidwiring layout complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The drive board is divided into multiple segments with ground terminals and power-supply terminals arranged at different positions along the longitudinal direction. Each segment handles specific drive signals, allowing independent optimization of wiring paths and reducing impedance variation between different nozzle groups.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the flexible substrate are assigned different wiring configurations tailored to local requirements. Ground terminals and power-supply terminals are strategically positioned to provide optimal local impedance control for each drive device, rather than using a uniform wiring layout throughout.

Inventive Principle:
Principle #3Local quality

2Reliability

If wiring length is increased to connect all terminals, then connectivity is improved, but wiring impedance variation increases

Engineering Contradiction:
Improvesignal connectivityVSAvoidwiring impedance uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

Multiple ground terminals are connected through ground wiring lines to establish equipotential regions across the drive board. This ensures that all ground references maintain the same potential level, reducing ground loops and impedance variation while maintaining reliable connectivity across the entire device.

Inventive Principle:
Principle #12Equipotentiality

Solution Approach 2:

Ground wiring lines and power-supply wiring lines act as intermediary conductors that mediate between the flexible substrate and the drive devices. These intermediary wiring layers provide controlled impedance paths, isolating signal variations and ensuring uniform electrical characteristics across different terminals.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If decoupling capacitors are added to stabilize drive signals, then drive waveform stability improves, but device complexity increases

Engineering Contradiction:
Improvedrive waveform stabilityVSAvoidcircuit component count
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Decoupling capacitors are pre-positioned at strategic locations on the flexible substrate before final assembly. These capacitors are placed in advance to compensate for anticipated signal variations, providing proactive stabilization of drive waveforms before signals reach the drive devices and nozzles.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The decoupling capacitors on the flexible substrate provide self-service stabilization by automatically compensating for power supply variations and signal noise locally at each drive device. This distributed capacitance approach allows each section to self-regulate its drive waveform without requiring complex external control circuits.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4378690B1Drive board, liquid jet head, and liquid jet recording device
Publication Date: 2025.11.12 SII PRINTEK INC
  • EP4378690B1 patent drawingFigure 1
  • EP4378690B1 patent drawingFigure 2
  • EP4378690B1 patent drawingFigure 3

AI summary

Drive board (13) configured to output a drive signal (Sd) to be applied to a liquid jet head (1) having a plurality of nozzles (Hn), including at least one drive device (41) which is mounted on a board surface (S), and which is configured to generate the drive signal configured to jet a liquid from the nozzles, and at least one constant-potential wiring line (Lv) which extends along a longitudinal direction (X) of the drive device in a mounting area (Am) of the drive device, and to which a predetermined constant potential is applied. The drive device includes a plurality of output terminals (Tout) which is arranged at respective positions different from each other along the longitudinal direction, and which is configured to individually output the drive signal, and constant-potential terminals (Tv) at three or more places which are arranged along the longitudinal direction (X), and which are electrically coupled to the constant-potential wiring line (Lv) to which the same constant potential is applied.