Thermal Printer Heating Element Grouping for Power Limit Management

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Solution Overview

Problem

Thermal printer units face challenges in reliably operating within the specified maximum current limits of the permanent voltage circuit, particularly when high power requirements are needed for printing, which can lead to inefficiencies and the need for additional power sources.

Innovation Solution

A method and device that group heating elements to be activated simultaneously based on the number of pixels to be printed and a predetermined maximum number, allowing for efficient power consumption management by activating groups at different times and assigning heating elements into blocks for flexible allocation, thereby reducing power consumption and eliminating the need for additional power sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If all heating elements are activated simultaneously to achieve maximum printing speed, then printing productivity is improved, but power consumption exceeds the maximum current limits of the permanent voltage circuit

Engineering Contradiction:
Improveprinting speedVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent divides the set of all heating elements into multiple groups that are activated sequentially rather than simultaneously. Each group contains a maximum number of heating elements that can be activated at once without exceeding the current limit. This segmentation allows the system to print entire lines faster by activating multiple groups in succession, rather than waiting for sequential pixel-by-pixel or element-by-element activation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements periodic activation of heating element groups, where each group is activated for a brief time interval, then deactivated before the next group is activated. This periodic action pattern enables the system to maintain high power consumption within safe limits while achieving fast printing by continuously cycling through multiple groups across the entire line.

Inventive Principle:
Principle #19Periodic action

2Use of energy by moving object

If heating elements are activated in small sequential groups to limit power consumption, then power consumption is controlled within current limits, but the number of time-delayed activations increases, reducing printing speed

Engineering Contradiction:
Improvepower consumptionVSAvoidprinting speed
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent dynamically adjusts the grouping and activation sequence of heating elements based on the specific printing requirements and current constraints. The system optimizes which heating elements are grouped together and in what sequence they are activated, adapting to different line configurations and content types to minimize the total activation time while respecting power limits.

Inventive Principle:
Principle #15Dynamics

3Power

If additional power sources are added to meet maximum current draw requirements, then power availability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvepower availabilityVSAvoidpower source configuration
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent enables the thermal printer unit to self-regulate its power consumption by implementing intelligent grouping and sequential activation of heating elements. The control system automatically manages the activation sequence to ensure power draw remains within the capabilities of the existing permanent voltage circuit, eliminating the need for additional power sources or complex power management hardware.

Inventive Principle:
Principle #25Self-service

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 approach ensures reliable operation of thermal printer units by limiting power consumption, reducing the number of time-delayed group activations, and allowing for cost-effective operation even under voltage fluctuations, expanding the unit's applicability to battery-powered or specialized applications.

Implementation Method 1

The heating elements associated with the printhead are activated and heated according to the character to be printed, and the substrate is blackened, for example, by brief direct contact with the heated elements

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a thermosensitive printing medium, which turns black when heated

Methodology Applied
Scientific EffectThermal blackening: Thermochromism

Data Source

PatentEP2155497B1Method and device for operating a thermal printing unit
Publication Date: 2019.07.10 CONTINENTAL AUTOMOTIVE GMBH
  • EP2155497B1 patent drawingFigure 1
  • EP2155497B1 patent drawingFigure 2
  • EP2155497B1 patent drawingFigure 3~4

AI summary

The invention relates to a thermal printing unit (TPU) comprising a print head (PH) and a heating element (HE) associated with the print head (PH), a heating element (HE) representing a pixel and the heating elements (HE) associated with the print head (PH) representing a pixel line (PL). The print head (PH) is designed to actuate the heating elements (HE) in the sense of printing on a print medium (TM). A type of grouping of heating elements (HE) to be simultaneously actuated is determined for each pixel line for operating the thermal printing unit (TPU). If a plurality of groups has been determined as a result of the type of grouping, the individual groups are actuated at different times from each other.