Thermal Transfer Printer Gear Synchronization Backlash Control

Solution Overview

Problem

Conventional thermal transfer line printers experience conveyance unevenness and color deviation during full-color recording due to backlash in the driving force transmission mechanism, leading to suboptimal recording quality and increased costs from separate motors for conveying rollers and platen rollers.

Innovation Solution

A re-transmission mechanism with a driving force transmission gear on the platen roller and intermediate gears that always mesh with driven rollers, allowing equal gear counts and adjustable backlash control to synchronize the rotation of conveying rollers with the platen roller, driven by a single motor, reducing the total number of gears and backlash.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If separate driving motors are used for conveying rollers and platen roller, then each component can be independently controlled, but the device complexity and cost increase

Engineering Contradiction:

Improveindependent control of conveying rollers and platen rollerVSAvoidnumber of driving motors

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent combines multiple driving functions into a single driving motor that drives both the conveying rollers and the platen roller through a synchronized gear mechanism. This merging of driving sources reduces the total number of motors while maintaining coordinated control of all components through the gear ratio relationships.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single driving motor performs multiple functions by driving different components through the gear train. The driving motor serves as a universal power source that can control both the conveying rollers and platen roller, eliminating the need for separate dedicated motors for each component.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Ease of operation

If multiple gears are used in the driving force transmission mechanism, then the driving force can be transmitted to multiple components, but the backlash increases causing conveyance unevenness

Engineering Contradiction:

Improvesynchronized conveyance of recording mediumVSAvoidconveyance uniformity

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent acknowledges the inherent backlash in gear mechanisms but converts this potential harm into a benefit by designing the gear train with an odd number of gears. This configuration ensures that backlash errors accumulate in a predictable manner that can be compensated for in the synchronization control, transforming the unavoidable mechanical imperfection into a manageable parameter.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the parameter of gear count to an odd number to optimize backlash compensation. By controlling the number of gear stages and their arrangement, the system transforms the backlash characteristic from a random error source into a predictable parameter that can be compensated for through control algorithms, thereby improving conveyance uniformity.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If separate driving motors are used for conveying rollers and platen roller, then each component can be independently controlled, but the cost increases

Engineering Contradiction:

Improveindependent control of conveying rollers and platen rollerVSAvoidmanufacturing cost

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The patent combines multiple driving functions into a single driving motor that drives both the conveying rollers and the platen roller through a synchronized gear mechanism. This merging of driving sources reduces the total number of motors while maintaining coordinated control of all components through the gear ratio relationships.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single driving motor performs multiple functions by driving different components through the gear train. The driving motor serves as a universal power source that can control both the conveying rollers and platen roller, eliminating the need for separate dedicated motors for each component.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 minimizes conveyance unevenness and color deviation, enabling high-quality full-color recording while reducing the number of motors and costs by ensuring precise and synchronized movement of the recording medium.

Implementation Method 1

selectively driving a plurality of heat generating elements of the line thermal head 105 on the basis of recording information while the ink film 103 and the recording medium 104 are conveyed to make them generate heat, thereby thermally transferring the ink of the ink film 103 to the recording medium 104

Methodology Applied

Scientific EffectThermal transfer: Conduction (thermal)

Data Source

PatentUS7439994B2Thermal transfer line printer

Publication Date: 2008.10.21 ALPS ALPINE CO LTD

AI summary

A printer capable of printing high-quality recording is provided. A driving force transmission gear mounted on a platen roller, driven rollers mounted on a pair of conveying rollers, respectively, and intermediate gears that always mesh with both the driving force transmission gear, and the driven rollers form a re-transmission mechanism that re-transmits the driving force transmitted to the platen roller from a driving motor to each of the one pair of conveying rollers. Also, gear supporting shafts that rotatably support intermediate gears are configured so as to be adjustable in position.