Heatable Film Carrier Layout for Uniform Panel Radiator Heating

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Solution Overview

Problem

In panel heaters, inhomogeneous current distribution at bends in the current path leads to local heat centers or 'hot spots', causing uneven heat distribution and potential damage, especially in transparent applications like vehicle windshields.

Innovation Solution

A plastic film carrier with an electrical heating layer divided by first and second separating zones, where the main current path changes direction at free zone ends, is used to create multiple parallel partial current paths, ensuring even current distribution and preventing hot spots.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If the heating layer is structured with dividing lines to form a tortuous current path, then the electrical resistance is increased and current path can be contacted using smaller connection electrodes, but the current distribution becomes inhomogeneous at bends and local heat centers arise

Engineering Contradiction:
Improvelocal heat centersVSAvoiddamage to heating layer or substrate
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The heating layer is segmented into multiple heating zones by dividing lines, which are further subdivided into partial current paths by secondary dividing lines. This segmentation distributes the current flow into multiple parallel paths, preventing concentration at bends and eliminating local heat centers while maintaining the tortuous path structure for increased resistance.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If the current path is bent to increase electrical resistance, then smaller connection electrodes can be used, but uneven heat distribution and optical impairment occur at overheating points

Engineering Contradiction:
Improveconnection electrode sizeVSAvoidheat distribution uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent introduces a second dimension of division by adding secondary dividing lines that create multiple parallel partial current paths within each heating zone. This dimensional approach distributes current across multiple paths simultaneously, maintaining the space-efficient tortuous design while achieving uniform heat distribution through parallel current distribution.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Power

If first separating zones are used to create a tortuous current path, then electrical resistance increases, but inhomogeneous current distribution occurs at free zone ends

Engineering Contradiction:
Improveelectrical resistanceVSAvoidcurrent distribution homogeneity
Core Design Contradiction:
PowerVSEase of operation

Solution Approach 1:

Each heating zone is segmented into multiple partial current paths using secondary dividing lines that extend from the first separating zones. This creates parallel current paths that distribute the electrical load uniformly, maintaining high resistance through the tortuous path while ensuring homogeneous current distribution across all paths.

Inventive Principle:
Principle #1Segmentation

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 design homogenizes current density and heat distribution, preventing overheating and damage, while simplifying production by allowing simultaneous creation of separation zones using a laser.

Implementation Method 1

an electrical heating layer for heating the carrier is applied to at least part of a carrier or film surface

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2698038B1Electrically heatable carrier and panel radiator, and method for the production thereof
Publication Date: 2016.11.09 SAINT GOBAIN VITRAGE SA
  • EP2698038B1 patent drawingFigure 1
  • EP2698038B1 patent drawingFigure 2
  • EP2698038B1 patent drawingFigure 3A~3B

AI summary

The invention relates to a carrier, in particular a plastic film, comprising an electrical heating layer that is applied to at least a portion of a carrier surface. The heating layer is electrically divided by one or more first separating zones, each of which is designed such that the current path changes the direction of flow thereof at the free zone ends, and one or more second separating zones, which are designed such that the current path changing the direction of flow thereof at the free zone ends is divided in at least some sections into a plurality of electrically parallel current sub-paths. One or more second separating zones are associated with at least one free zone end of a first separating zone, wherein the second separating zones are arranged in an aligned extension to the first separating zone.