Dual Thermal Head Bidirectional Printing for Paper Conservation

Solution Overview

Problem

Thermal printers struggle to efficiently print on both sides of thermal paper sheets with heat-sensitive layers, requiring complex processing similar to copying machines, which is time-consuming and unsuitable for rapid tasks like issuing sales receipts.

Innovation Solution

A thermal printer design with dual thermal heads for both surfaces of the paper, controlled by a CPU to enable forward and backward printing on both sides, allowing for efficient double-side printing without the need for reversing the paper.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If a thermal paper sheet with heat-sensitive layers on both surfaces is used to print data on both surfaces, then the paper length can be reduced and paper conservation is achieved, but the printing process becomes time-consuming due to complex processing similar to copying machines

Engineering Contradiction:

Improvepaper consumptionVSAvoidprinting time

Core Design Contradiction:

Loss of substanceVSLoss of time

Solution Approach 1:

The printing system is segmented into two independent thermal heads: a first thermal head for printing on the first surface and a second thermal head for printing on the second surface. This segmentation allows both surfaces to be printed simultaneously without requiring paper reversal, thus reducing printing time while maintaining paper conservation benefits

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from sequential single-side printing to parallel double-side printing by adding a second thermal head operating on the opposite surface. This dimensional expansion from one printing surface to two simultaneous printing surfaces eliminates the time penalty associated with paper reversal while preserving the paper length reduction advantage

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Loss of substance

If a thermal paper sheet with heat-sensitive layers on both surfaces is used, then paper length is reduced, but the device complexity increases due to the need for dual thermal heads and bidirectional control

Engineering Contradiction:

Improvepaper consumptionVSAvoidprinter structure

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The printing system is segmented into two independent thermal heads: a first thermal head for printing on the first surface and a second thermal head for printing on the second surface. This segmentation allows both surfaces to be printed simultaneously without requiring paper reversal, thus reducing printing time while maintaining paper conservation benefits

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Both thermal heads share common functional characteristics and control mechanisms, allowing the system to handle both single-side and double-side printing requirements. The control section provides universal bidirectional control for both heads, enabling the system to adapt to different printing needs without requiring entirely separate control systems

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If a single thermal head is used to print on one surface only, then the device structure is simple, but paper length becomes excessive and handling becomes difficult

Engineering Contradiction:

Improveprinter structureVSAvoidpaper handling

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

The invention transitions from sequential single-side printing to parallel double-side printing by adding a second thermal head operating on the opposite surface. This dimensional expansion from one printing surface to two simultaneous printing surfaces eliminates the time penalty associated with paper reversal while preserving the paper length reduction advantage

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

Enables rapid printing on both sides of thermal paper sheets, reducing paper length and handling difficulties, making it suitable for applications like sales receipts while conserving paper and enhancing usability.

Implementation Method 1

a thermal head that comes into contact with the other surface of the thermal paper sheet; and a control section that selectively controls forward printing and backward printing of the first thermal head with respect to the first surface of the thermal paper sheet

Methodology Applied

Scientific EffectThermal heating: Heating

Data Source

PatentUS7679632B2Thermal printer and method of controlling the same

Publication Date: 2010.03.16 TOSHIBA TEC KK

AI summary

A first thermal head that comes into contact with a front surface of a thermal paper sheet, and a second thermal head that comes into contact with a rear surface of the thermal paper sheet are provided. Further, forward printing and backward printing of the first thermal head with respect to the front surface of the thermal paper sheet are selectively controlled. Furthermore, forward printing and backward printing of the thermal head with respect to the rear surface of the thermal paper sheet are selectively controlled.