Thermal Printer Head Support Plate Swing Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Thermal printers face issues with uneven nip portion width due to platen roller inclination, leading to variations in friction resistance and print quality, and existing solutions increase cost and complexity.

Innovation Solution

A thermal printer design with a swingable head support plate and urging members that allows the thermal head to maintain even contact with the platen roller, ensuring consistent nip width through adjustable support and relief portions, eliminating the need for additional positioning mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a positioning mechanism (lock arm) is provided to hold the platen roller, then the platen roller positioning is reliable and inclination is reduced, but cost and configuration complexity increase

Engineering Contradiction:
Improveplaten roller positioning reliabilityVSAvoidpositioning mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The head support plate automatically adjusts its own position and orientation through the swing support portion, eliminating the need for external positioning mechanisms. The swingable design allows the head support plate to self-align with the platen roller, achieving reliable positioning without additional locking components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The head support plate is designed to be swingable rather than fixed, allowing it to dynamically adjust its position and orientation. This dynamic adjustment capability enables the system to automatically compensate for misalignment and maintain proper nip portion width without requiring static positioning mechanisms.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If the platen roller is supported in a fixed position, then the configuration is simple, but the nip portion width becomes uneven due to roller inclination

Engineering Contradiction:
Improvesupport configuration simplicityVSAvoidnip portion width uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The head support plate transitions from a fixed to a swingable design, enabling it to dynamically adjust its orientation. This allows the system to maintain uniform nip portion width by automatically compensating for platen roller inclination, achieving precision without complex fixed positioning structures.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The swingable head support plate changes its angular parameter (orientation) to adapt to platen roller position variations. By adjusting its swing angle, the head support plate maintains optimal alignment with the platen roller, ensuring uniform nip portion width despite roller inclination.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the nip portion width is increased to ensure adequate contact, then print quality improves, but friction resistance increases and motor load becomes larger

Engineering Contradiction:
Improveprint qualityVSAvoidfriction resistance
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The swingable head support plate adjusts the orientation parameter to optimize the nip portion geometry. This ensures adequate contact width for print quality while maintaining the optimal angle that minimizes friction resistance between the recording paper, thermal head, and platen roller.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The head support plate applies pressing force locally at the optimal position and angle through its swingable design. This concentrates the necessary contact pressure where needed for print quality while minimizing overall friction resistance by avoiding excessive or misaligned pressing forces.

Inventive Principle:
Principle #3Local quality

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 maintains uniform nip width, enhancing print quality while reducing costs and simplifying the printer's configuration by allowing the platen roller to be supported without additional positioning mechanisms, thus improving print reliability and reducing size and material requirements.

Implementation Method 1

an urging member configured to urge the head support plate in a direction of causing the thermal head to approach the platen roller

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

friction resistance generated among the platen roller, the thermal head, and the recording paper

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3395578B1Thermal printer and portable terminal
Publication Date: 2020.01.29 SEIKO INSTR INC
  • EP3395578B1 patent drawingFigure 1
  • EP3395578B1 patent drawingFigure 2
  • EP3395578B1 patent drawingFigure 3

AI summary

A thermal printer (13) includes a frame (30), a platen roller (23) supported on the frame (30) so as to be rotatable about a first direction, a head support plate (71) supported on the frame (30), and a thermal head (21) fixed to the head support plate (71). The platen roller (23) includes a transmission portion (56) configured to receive power transmitted from a drive source (61) at an end portion on a first side in the first direction. The thermal head (21) is configured to nip recording paper (P) between the thermal head (21) and the platen roller (23) in a second direction orthogonal to the first direction to perform printing on the recording paper (P). The frame (30) includes a swing support portion (70) configured to support the head support plate (71) so that the head support plate (71) is swingable about the first direction and a third direction orthogonal to the first direction and the second direction. The thermal head (21) is fixed to a portion of the head support plate (71) located on a first side in the third direction with respect to the swing support portion (70). Between a portion of the head support plate (71) located on a second side in the third direction with respect to the swing support portion (70) and the frame (30), an urging member (79) configured to urge the head support plate (71) in a direction of causing the thermal head (21) to approach the platen roller (23) is interposed.