Electrophoretic Display Optical Device with Light Shielding Patterns

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Solution Overview

Problem

Liquid crystal display devices face issues with optical degradation causing a rise in operating voltage due to incident light exposure, leading to decreased surface charging of electrophoretic elements and unstable operation, and existing solutions like vacuum-sputtered aluminum electrodes result in unstable electrophoretic display devices.

Innovation Solution

An optical device with conductive light shielding patterns on one transparent substrate and a transparent conductive film on another, along with light transmissive regions and electrophoretic elements, allows for adjustable light emission control by changing the dispersion state of electrophoretic particles using external electric fields, preventing light ingress and maintaining stable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If electrophoretic elements are exposed to incident light, then the display can be viewed, but optical degradation occurs causing a rise in operating voltage and decreased surface charging

Engineering Contradiction:

Improvelight transmissionVSAvoidoperating voltage stability

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

A light shielding film is introduced as an intermediary component between the electrophoretic elements and the incident light. This film selectively blocks harmful light wavelengths that cause optical degradation while allowing sufficient light transmission for display functionality, thereby protecting the electrophoretic elements from voltage instability without completely blocking light

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a transparent conductive film is used on the light incident side, then electrical conductivity is provided, but light exposure causes optical degradation

Engineering Contradiction:

Improveelectrical conductivityVSAvoidoptical degradation from light

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs a composite structure combining a light shielding film with light transmissive regions and a transparent conductive film. The light shielding film material blocks harmful light, while the transparent conductive film provides electrical conductivity, creating a composite system that achieves both protection and functionality

Inventive Principle:

Principle #40Composite materials

3Adaptability or versatility

If the display operates in wide-visible range mode, then viewing flexibility is improved, but information leakage risk increases

Engineering Contradiction:

Improveviewing angle rangeVSAvoidinformation leakage

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic control of the light shielding film's properties or positioning based on viewing conditions. The system can adjust between different shielding states to switch between wide-visible range mode (for flexibility) and narrow-visible range mode (for security), allowing adaptive response to different operational requirements

Inventive Principle:

Principle #15Dynamics

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 effectively prevents optical degradation, maintains stable operation by reducing operating voltage, and ensures reliable light direction control, enhancing the performance and reliability of liquid crystal display devices.

Implementation Method 1

each electrophoretic element 460 is disposed in gaps between these light transmissive regions 440. Here, transparent conductive films 451 and 452 are formed between the transparent substrate 421 and the light transmissive regions 440 and between the transparent substrate 422 and the light transmissive regions 440, respectively. The optical device 410 in which each electrophoretic element 460 is disposed in gaps between high-aspect ratio light transmissive regions 440 planarly and independently laid out on the transparent substrate 421 as described above is configured such that the dispersion state of the electrophoretic elements 460 is controlled by externally applying electric fields through the transparent conductive films 451 and 452

Methodology Applied

Scientific EffectElectrophoresis: Electrophoresis

Data Source

PatentUS9874799B2Optical device, manufacturing method of optical device, and display device, electronic device and illuminating device including optical device

Publication Date: 2018.01.23 TIANMA MICRO ELECTRONICS CO LTD

AI summary

An optical device including first and second transparent substrates disposed so that the principal surfaces thereof face each other; conductive light shielding patterns disposed on the principal surface side of the first transparent substrate; a transparent conductive film disposed on the principal surface of the second transparent substrate; a plurality of light transmissive regions disposed on the first transparent substrate; and an electrophoretic element disposed in gaps between each adjacent light transmissive regions is configured such that the dispersion state of electrophoretic particles 61 is changed by externally applied electric fields, thereby changing the range of outgoing directions of transmitted light. Thus, it is possible to relieve a decrease in the amount of charging of an electrophoretic element caused by the ingress of incident light and to ensure operation stability.