Conductive Wire Grid Polarizer for Touch Sensing

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Solution Overview

Problem

In-cell touch sensing technology has difficulty detecting hover inputs due to the number of layers separating the touch sensor from the user's finger, leading to lower sensitivity and increased device thickness, while conventional touch sensors with separate touch sensors and displays can be thicker and less efficient.

Innovation Solution

A touch sensitive display device utilizing a conductive wire grid polarizer as a touch sensor electrode, which acts as both an optical polarizer and an electrical conductor, reducing the number of layers and improving hover detection by positioning the touch sensor closer to the touch surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional separate touch sensor and display layers are used, then touch sensing function is achieved, but device thickness increases and hover detection sensitivity decreases

Engineering Contradiction:
Improvehover detection sensitivityVSAvoiddevice thickness
Core Design Contradiction:
Measurement precisionVSLength of stationary object

Solution Approach 1:

The patent combines the polarizer and touch sensor electrode into a single integrated layer. The conductive polarizer serves dual functions as both an optical polarizing element and a touch sensing electrode, eliminating the need for separate touch sensor layers and reducing overall device thickness while improving hover detection sensitivity through closer proximity to the touch surface.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The conductive polarizer performs multiple functions simultaneously: it polarizes light for the display function and acts as an electrode for touch sensing. This multi-functional element replaces what would traditionally require separate components, reducing layer count and improving hover detection by positioning the sensing function closer to the user's finger.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If multiple separate layers are used for touch sensor and display, then functional requirements are met, but manufacturing complexity increases

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidnumber of layers
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent merges the polarizer and touch electrode fabrication into a single process step. The conductive polarizer is deposited and patterned together with the polarizing structure, eliminating the need for separate touch electrode deposition and patterning steps, thereby simplifying manufacturing and reducing the number of processing layers.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

By designing the polarizer to also function as the touch electrode, the patent creates a universal component that fulfills both optical and sensing requirements. This reduces the total number of layers that need to be manufactured and assembled, simplifying the overall manufacturing process while meeting all functional requirements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 use of a conductive wire grid polarizer as a touch sensor electrode reduces device thickness, enhances hover sensitivity, and improves light transmittance, allowing for higher contrast images and reduced battery drain by minimizing reflections and enabling higher frequency touch sensing.

Implementation Method 1

a conductive wire grid polarizer coupled to the transparent electrode layer via a dielectric layer

Methodology Applied
Scientific EffectPolarization: Polarisation

Implementation Method 2

a touch sensor that utilizes a conductive wire grid polarizer as a touch sensor electrode

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3058447B1Touch and hover sensing with conductive polarizer
Publication Date: 2018.03.07 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3058447B1 patent drawingFigure 1A~1B
  • EP3058447B1 patent drawingFigure 2
  • EP3058447B1 patent drawingFigure 3

AI summary

Embodiments are disclosed that relate to touch and proximity sensing with a touch sensor that utilizes a conductive polarizer as a touch sensor electrode. For example, one disclosed embodiment provides a touch sensitive display device including a display having a transparent electrode layer including a plurality of transparent electrodes, a conductive polarizer coupled to the transparent electrode layer via a dielectric layer, a touch sensing driver circuit electrically connected to one of the transparent electrode layer and the conductive polarizer, and a touch sensing receiver circuit electrically connected to another of the transparent electrode layer and the conductive polarizer.