Thermal Printer Printhead Coding via Modified Heating Elements

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Solution Overview

Problem

Existing thermal printers face challenges in securely and cost-effectively encoding print heads, particularly due to the high costs associated with electronic coding systems and the vulnerability of mechanical coding methods.

Innovation Solution

A thermal printer with a print head featuring additional heating elements outside the print area, whose electrical resistance can be selectively modified for coding, integrated with control electronics and a test circuit to verify the resistance, ensuring reliable and cost-effective encoding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electronic memory modules are used to store identification numbers on print heads, then coding reliability is improved, but manufacturing cost increases

Engineering Contradiction:
Improvecoding reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts the coding function from the main print head body and implements it using separate additional heating elements. These additional heating elements can be selectively activated or deactivated to create different coding patterns, providing reliable identification without requiring expensive electronic memory modules on each print head.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the operational state parameter of heating elements (active/inactive) to encode identification information. By selectively modifying which additional heating elements are functional, unique codes are created without adding complex electronic storage components, thus maintaining manufacturing simplicity while achieving reliable coding.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If mechanical hole patterns are used for coding, then manufacturing cost is reduced, but security and reliability deteriorate due to ease of imitation

Engineering Contradiction:
Improvemanufacturing costVSAvoidcoding security
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention replaces the mechanical hole pattern system with an electrical/thermal system. Instead of physical holes that can be visually inspected and imitated, the coding is achieved through electrical control of additional heating elements, which can be verified through electrical resistance measurements and thermal behavior, significantly improving security while maintaining manufacturing simplicity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If the print area is reduced by removing heating elements, then coding flexibility is improved, but printing capability deteriorates

Engineering Contradiction:
Improvecoding flexibilityVSAvoidprinting capability
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The invention segments the heating elements into two distinct groups: additional heating elements within the print area that maintain printing capability, and further additional heating elements outside the print area that provide coding functionality. This segmentation allows both printing and coding functions to operate simultaneously without compromising either capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention extends the coding functionality to a new spatial dimension by placing additional heating elements outside the traditional print area. This dimensional extension allows coding information to be encoded without reducing the print area, thereby maintaining full printing capability while achieving coding flexibility.

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

This solution provides a secure and cost-effective method for encoding thermal printer heads, ensuring optimal print quality by verifying the correct installation of the print head and preventing errors, thus maintaining high-quality printing.

Implementation Method 1

the targeted local heating of the print head directly or indirectly brings about a color change on the print medium to be printed

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

at least one of the additional heating elements having an electrical resistance that differs from the electrical resistance of the heating elements arranged in the printing area

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentEP2319695B8Print head for a thermal printer, method for manufacturing the print head for thermal printer and the thermal printer
Publication Date: 2013.04.10 CARL VALENTIN

AI summary

The invention relates to a printhead (10, 21) for a thermal printer (20) with a printing area (A-A') for printing a printing medium, a plurality of heating elements (1) arranged in at least one line in the printing area (A-A'), a control electronics unit (2) with which the heating elements (1) can be controlled and a connector (6), wherein one or more further heating elements (8, 9) are arranged outside the printing area, which can also be controlled by the control electronics unit (2), wherein at least one of the further heating elements (8, 9) has a property, in particular an electrical resistance, which deviates from a standard property, in particular the electrical resistance, of the heating elements (1) arranged in the printing area (A-A');A method for manufacturing a printhead (10, 21) for a thermal printer (20), comprising the steps of providing a substrate (11) with a plurality of heating elements (1, 8, 9) having at least one line of heating elements (1) and control electronics (2) by means of which the heating elements (1, 8, 9) can be controlled; defining a printing area of ​​the printhead (10, 21) in which a printing medium can be printed with the printhead (10, 21), wherein the printing area (A-A') is defined such that one or more heating elements (8, 9) are located outside the printing area;and carrying out a targeted modification of the properties of one or more of the heating elements (8, 9) located outside the printing area, as well as a thermal printer (20) with device electronics (26) for controlling a printhead (10, 21) and a printhead (10, 21) controllable by the device electronics (26) with a plurality of heating elements (1), wherein the device electronics (26) has a test circuit (25) for printhead verification, wherein the printhead (10, 21) has one or more further heating elements (8, 9) whose properties differ with respect to at least one standard property of the heating elements (1, 8, 9), and wherein the test circuit (25) for printhead verification is designed to test this property on at least some of the heating elements (1, 8, 9).