Thermal Printer Liquid Guide Structure for Water Ingress Prevention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing thermal printers are ineffective in preventing water immersion in the housing when placed in a horizontal posture, such as on a floor, where liquid can enter through the sheet delivery port and potentially damage internal components.

Innovation Solution

A thermal printer design featuring a guide shaped portion extending along the up-and-down direction between the open button and the housing, which guides liquid downward to a retaining portion, preventing it from splashing onto internal components and allowing it to be drained effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a retaining portion is provided to retain liquid in carriage posture, then water immersion prevention is improved in carriage posture, but water immersion prevention is insufficient in horizontal posture

Engineering Contradiction:
Improvewater immersion preventionVSAvoidposture adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent introduces a movable cover that can change its position based on the printer's posture. The cover includes a hinge mechanism that allows it to rotate between a closed position (carriage posture) and an open position (horizontal posture), dynamically adapting to different operating conditions to prevent water immersion effectively in both postures

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent divides the housing into distinct functional zones: a retaining portion for carriage posture and an openable cover area for horizontal posture protection. This segmentation allows each portion to address water immersion prevention specifically for its intended posture, improving overall adaptability

Inventive Principle:
Principle #1Segmentation

2Reliability

If the cover is made openable and closable for horizontal posture protection, then water immersion prevention in horizontal posture is improved, but device complexity increases

Engineering Contradiction:
Improvewater immersion preventionVSAvoidcover mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cover mechanism is designed to be self-operating through a hinge joint that automatically positions the cover based on the printer's orientation. The hinge allows the cover to rotate and lock into appropriate positions without requiring additional actuators or complex control systems, maintaining simplicity while providing posture-specific protection

Inventive Principle:
Principle #25Self-service

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

The design effectively prevents water immersion in the printer housing by reducing liquid momentum and guiding it to a retaining area, ensuring internal components like the substrate remain dry and functional.

Implementation Method 1

a guide shaped portion, which is provided below a gap between the open button and the housing and at a position corresponding to the gap, and extends along an up-and-down direction

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP4434761B1Thermal printer
Publication Date: 2025.12.31 SEIKO INSTR INC
  • EP4434761B1 patent drawingFigure 1
  • EP4434761B1 patent drawingFigure 2
  • EP4434761B1 patent drawingFigure 3

AI summary

A thermal printer (1) includes: a housing (2); a printing unit (5), which includes a head unit (51) and a platen unit (52) including a platen roller, and is received in the housing (2); a cover (3) configured to be capable of opening and closing the housing (2); an open button (4) of the cover (3); and a guide shaped portion (6), which is provided below a gap between the open button (4) and the housing (2) and at a position corresponding to the gap, and extends along an up-and-down direction in a horizontal posture that is a state of the thermal printer (1) placed such that a sheet delivery port (32) defined between the cover (3) and the housing (2) is facing upward.