Patterned Display Reflector for NFC Signal Transparency

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Solution Overview

Problem

In mobile payment readers, the bulky display devices often attenuate wireless NFC signals, leading to increased transmit power requirements and reduced battery life, as the metallic reflectors in these devices act as conductive shields blocking electromagnetic energy.

Innovation Solution

The reflector in the display device is designed with small gaps arranged in a pattern to reduce eddy current loop sizes, minimizing parasitic power consumption while maintaining mechanical integrity and optical efficiency, thereby enhancing signal transparency without significant impairment to heat sinking or light production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a metallic reflector is used in the display device to improve optical efficiency and mechanical integrity, then the display device can maintain structural strength and light reflection, but the metallic reflector acts as a conductive shield that attenuates wireless NFC signals

Engineering Contradiction:

Improvemechanical integrityVSAvoidsignal attenuation

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The continuous metallic reflector is segmented into multiple isolated conductive elements arranged in a pattern. This segmentation breaks up the large conductive surface into smaller discrete elements, reducing the reflector's ability to act as a continuous electromagnetic shield while preserving its optical reflection function. The gaps between elements allow wireless signals to pass through with reduced attenuation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The reflector is designed with a porous or perforated structure containing numerous small gaps or openings distributed throughout the metallic surface. This porous configuration allows electromagnetic waves to penetrate through the reflector more easily while the metallic portions maintain sufficient optical reflectivity. The patterned gaps reduce parasitic power consumption by minimizing eddy current formation.

Inventive Principle:

Principle #31Porous materials

2Reliability

If the reader's transmit power is increased to compensate for signal attenuation from the display device, then the wireless signal can penetrate through the display device, but the power requirements increase and battery life is reduced

Engineering Contradiction:

Improvesignal transmissionVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The invention converts the harmful effect of the metallic reflector (signal attenuation) into a beneficial outcome by modifying its structure. The patterned gaps in the reflector, which initially seem to compromise structural integrity, actually reduce electromagnetic shielding effectiveness. This transforms the reflector from a harmful attenuating element into a component that allows signal penetration while maintaining its primary optical and mechanical functions, thereby reducing the need for increased transmit power.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Loss of energy

If gaps are added to the reflector to reduce eddy current loop sizes and minimize parasitic power consumption, then signal transparency is enhanced, but the mechanical integrity and optical efficiency may be impaired

Engineering Contradiction:

Improveparasitic power consumptionVSAvoidmechanical integrity

Core Design Contradiction:

Loss of energyVSStrength

Solution Approach 1:

The reflector is designed with non-uniform local properties: certain regions contain gaps or openings while other regions maintain continuous metallic structure. The gap pattern is optimized to specifically target eddy current reduction in areas where it most affects parasitic power consumption, while preserving mechanical strength in load-bearing regions. This localized modification allows the reflector to minimize energy loss without significantly compromising overall structural integrity.

Inventive Principle:

Principle #3Local quality

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 reduces signal attenuation, lowering the required transmit power and extending battery life in mobile payment readers by minimizing parasitic power consumption without compromising mechanical or optical performance.

Implementation Method 1

the metallic reflector in these devices act as conductive shields blocking electromagnetic energy

Methodology Applied

Scientific EffectElectromagnetic reflection: Reflection

Implementation Method 2

a transmitter that wirelessly transmits a wireless signal from an antenna

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentUS10809564B1Systems and methods for improving transparency of display devices to wireless signals

Publication Date: 2020.10.20 BLOCK INC

AI summary

A wireless communication device has a display device and a transmitter that wirelessly transmits a wireless (e.g., NFC) signal from an antenna. The antenna is positioned such that the display device may be between the antenna and another wireless communication device that is to receive the signal, and the display device may attenuate such signal. A reflector of the display device is patterned with small gaps in order to limit the loop sizes of eddy currents that are induced by the wireless signal, thereby reducing parasitic power consumption of the reflector to the wireless signal. Thus, the presence of the gaps in the reflector improves the transparency of the display device to the wireless signal without significantly affecting the performance of the reflector in sinking heat and reflecting light.