Visible Light IR Filter with Distorted MOF Portions

Solution Overview

Problem

Embossing or distorting multilayer optical films used in IR blocking filters can alter their reflection spectrum, causing them to be undetected by IR-based systems, as the distorted portions reflect different wavelengths than the non-embossed areas, leading to inconsistent infrared blocking performance.

Innovation Solution

A multilayer optical film with distorted portions is designed to have a second reflection band, and an IR blocking material is selectively applied to these distorted areas to maintain effective infrared blocking, ensuring consistent detection by IR-based systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If multilayer optical film is embossed or distorted to create security features, then visual appearance and security are improved, but infrared reflection spectrum changes causing inconsistent IR blocking performance

Engineering Contradiction:

Improvesecurity feature creationVSAvoidIR blocking performance consistency

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by selectively positioning IR blocking material only in the distorted portions of the multilayer optical film where the reflection spectrum has changed. This targeted approach maintains IR blocking performance in the distorted areas without affecting the overall visual appearance and security features of the card.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining the multilayer optical film with additional IR blocking material applied to specific distorted portions. This composite structure allows the card to maintain both its visual security features and consistent infrared blocking performance across different detection systems.

Inventive Principle:

Principle #40Composite materials

2Shape

If multilayer optical film is distorted to create visual effects, then aesthetic appeal and security features are enhanced, but detection reliability by IR-based systems deteriorates

Engineering Contradiction:

Improvevisual appearanceVSAvoidIR detection consistency

Core Design Contradiction:

ShapeVSMeasurement precision

Solution Approach 1:

The patent applies local quality by selectively positioning IR blocking material only in the distorted portions of the multilayer optical film where the reflection spectrum has changed. This targeted approach maintains IR blocking performance in the distorted areas without affecting the overall visual appearance and security features of the card.

Inventive Principle:

Principle #3Local quality

3Reliability

If uniform IR blocking is applied across the entire film, then infrared blocking performance is maintained, but visual security features and aesthetic appeal are lost

Engineering Contradiction:

ImproveIR blocking performanceVSAvoidvisual appearance

Core Design Contradiction:

ReliabilityVSShape

Solution Approach 1:

The patent applies local quality by selectively positioning IR blocking material only in the distorted portions of the multilayer optical film where the reflection spectrum has changed. This targeted approach maintains IR blocking performance in the distorted areas without affecting the overall visual appearance and security features of the card.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the IR blocking function by applying it only to specific distorted portions rather than uniformly across the entire film. This segmentation allows different regions of the card to have different functions: distorted portions with IR blocking material maintain detection reliability, while other portions preserve visual appearance and security features.

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

The solution ensures that the IR blocking filters maintain their functionality even after distortion, allowing transparent financial transaction cards to be properly detected by IR-based systems, while also providing visually striking security features.

Implementation Method 1

a multilayer interference film whose individual layer thicknesses are tailored to produce a reflection band that reflects infrared (IR) light

Methodology Applied

Scientific EffectInterference: Interference

Implementation Method 2

the distorted portions having a second reflection band different from the first reflection band

Methodology Applied

Scientific EffectInterference: Interference

Data Source

PatentUS7636193B2Visible light-transmissive IR filter with distorted portions

Publication Date: 2009.12.22 3M INNOVATIVE PROPERTIES CO

AI summary

The present application discloses filters and methods of making filters. In one aspect, a filter comprises a multilayer optical film (MOF) having a first reflection band, the MOF including distorted portions, the distorted portions having a second reflection band different from the first reflection band, a transparent outer layer disposed on a first side of the MOF, and an IR blocking material residing on the MOF and between the transparent outer layer and the MOF, wherein the IR blocking material is selectively disposed in the distorted portions. In another aspect, a method of producing a filter comprises the steps of providing a multilayer optical film (MOF) having a first reflection band, distorting portions of the MOF, the distorted portions having a second reflection band, different from the first reflection band, and transferring a layer of IR blocking material to the distorted portions of the MOF.