Head Unit Circuit Board Stacking for High Density

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Solution Overview

Problem

The existing head units with larger circuit boards cannot be arranged with high density in a line due to increased dimensions, leading to interference between units.

Innovation Solution

The head unit design includes power supply circuits and integrated circuits arranged along the stacking direction, with a holding plate and screws to secure the circuit board, and a guide member to prevent incorrect orientation and movement, allowing for high-density arrangement without increasing the longitudinal size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the circuit board size is increased to accommodate more power supply circuits and integrated circuits, then the functionality and reliability of the head unit are improved, but the longitudinal dimension of the head unit increases, preventing high-density arrangement

Engineering Contradiction:
ImprovereliabilityVSAvoidlongitudinal dimension
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent transitions from a planar arrangement of circuits to a three-dimensional stacked configuration. Power supply circuits and integrated circuits are arranged in multiple layers along the stacking direction (thickness direction), allowing more components to be accommodated without increasing the longitudinal dimension. The circuit board is divided into multiple layers with circuits distributed across these layers, effectively utilizing the vertical dimension to increase component density while maintaining a compact longitudinal profile.

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

2Productivity

If multiple head units are arranged in high density along the longitudinal direction, then the productivity and output of the liquid ejection apparatus are improved, but interference between adjacent head units occurs due to their size

Engineering Contradiction:
ImproveproductivityVSAvoidinterference between head units
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

By stacking circuits vertically along the thickness direction rather than extending them longitudinally, the head unit achieves a compact form factor in the longitudinal dimension. This dimensional reorganization allows multiple head units to be closely spaced without interfering with each other, thereby enabling high-density arrangements that increase productivity while avoiding harmful interference between adjacent units.

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

Solution Approach 2:

The circuit board is segmented into multiple layers with different circuit arrangements on each layer. Power supply circuits and integrated circuits are divided and distributed across these layers, allowing for a more efficient spatial organization that reduces the longitudinal footprint of each head unit, thus enabling closer spacing and higher density arrangements.

Inventive Principle:
Principle #1Segmentation

3Stability of the object's composition

If the circuit board is secured with holding plate and screws, then the structural stability and reliability of the head unit are improved, but the device complexity increases

Engineering Contradiction:
Improvestructural stabilityVSAvoiddevice complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The holding plate is designed with multiple through-holes positioned at specific locations to accommodate screws that secure the circuit board. This segmented approach with strategically placed fastening points provides adequate structural stability without requiring excessive fastening elements, thereby balancing reliability with manageable device complexity.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3461641B1Head unit and liquid ejection apparatus
Publication Date: 2020.08.05 BROTHER KOGYO KK
  • EP3461641B1 patent drawingFigure 1
  • EP3461641B1 patent drawingFigure 2
  • EP3461641B1 patent drawingFigure 3

AI summary

Ahead unit (100) includes a circuit board (80), a casing (110), and a head module (70) including: a nozzle plate (780) and a liquid-passage defining member (720) stacked on each other in a stacking direction; a drive element (710); and an interconnect member (760). A distance between a first end (72a) and a second end (72b) of the nozzle plate (780) which are spaced in a first direction is greater than a distance between a third end (72c) and a fourth end (72d) of the nozzle plate (780) which are spaced in a second direction. A distance between a seventh end (87) and an eighth end (88) of the circuit board (80) which are spaced in the stacking direction is greater than a distance between a fifth end (85) and a sixth end (86) of the circuit board (80) which are spaced in the first direction.