Bobbin Gear Integration for Thermal Transfer Printers

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Solution Overview

Problem

Thermal transfer printers face increased production costs and cumbersome operations due to the separate driving flange in bobbins, which also lead to scratching on touch rollers during ribbon winding.

Innovation Solution

A cylindrical bobbin body with a gear having trapezoidal teeth on one end surface, reducing the number of structural parts and eliminating driving irregularities, allowing for smooth engagement with the drive gear without a separate flange, and incorporating a circumferential groove or projection for positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate driving flange is mounted on the bobbin body, then the bobbin can be driven by a drive gear, but the number of structural parts increases and production cost increases

Engineering Contradiction:

Improvedriving functionVSAvoidnumber of structural parts

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the driving flange and bobbin body into a single integrated component. The gear is formed directly on the bobbin body as one piece, eliminating the need for a separate driving flange. This integration reduces the number of parts while maintaining the driving function through the gear engagement with the drive gear.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If driving irregularities are formed on the outer surface of the bobbin body, then the bobbin can be driven, but scratches are formed on the touch roll

Engineering Contradiction:

Improvedriving functionVSAvoidscratches on touch roll

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent moves the gear from the outer surface (2D surface modification) to the end surface (3D dimensional change) of the bobbin body. The gear is formed on the end surface perpendicular to the axis, allowing drive gear engagement without creating surface irregularities on the outer cylindrical surface that would otherwise scratch the touch roll.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If a separate driving flange is used, then driving is enabled, but disposal operation becomes cumbersome

Engineering Contradiction:

Improvedriving functionVSAvoiddisposal operation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

By integrating the gear into the bobbin body as a single piece, the patent simplifies the overall structure and makes disposal easier. The integrated design eliminates separate components that would need to be separated during disposal, allowing the entire bobbin assembly to be removed and disposed of as one unit without cumbersome disassembly operations.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentEP3150534B1Bobbin for thermal transfer sheet or image receiving sheet, bobbin/sheet combination, and thermal transfer printer

Publication Date: 2018.11.07 DAI NIPPON PRINTING CO LTD

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AI summary

There is provided a bobbin for a thermal transfer sheet or an image-receiving sheet which can reduce the number of parts and can have a smooth surface. The bobbin includes a cylindrical bobbin body 11. A gear 12 including a number of teeth 13 is formed in one end surface of the bobbin body 11. The teeth 13 of the gear 12 each have the shape of a trapezoid when viewed from the side. One lateral side 13b of the trapezoid extends in the axial direction of the bobbin body 11.