Bendable Light Guide Film with Planar Optical Units

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Flexible liquid crystal display backlight units with light guide portions on the rear surface face challenges in maintaining positional accuracy and preventing light leakage, leading to inadequate brightness adjustment and halo formation when bent or subjected to impact.

Innovation Solution

A light guide film comprising optical units with light guide and emission portions, where the light guide portions guide light to the emission portions, and a resin portion fills the gaps between adjacent units, ensuring the light guide and emission portions are parallel and securely positioned to prevent misalignment and contact, thereby maintaining light directionality and brightness control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If light guide portions are arranged on the rear surface side of emission portions to enable local dimming, then brightness adjustment per region is improved, but positional relationship deviation occurs when bent or subjected to impact

Engineering Contradiction:

Improvebrightness adjustment per regionVSAvoidpositional relationship between light guide portions and emission portions

Core Design Contradiction:

Illumination intensityVSManufacturing precision

Solution Approach 1:

The light guide portions and emission portions are integrated into a single light guide film structure, eliminating the need for separate arrangement of light guide portions on the rear surface. This merging ensures that the light guide portions and emission portions maintain their positional relationship even when bent or subjected to impact, while still enabling local dimming through independent light control.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from a three-dimensional arrangement (light guide portions on the rear surface side) to a two-dimensional planar arrangement (light guide portions and emission portions in the same plane). This dimensional change simplifies the structure and prevents positional deviation while maintaining local dimming capability through precise light incidence control.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Illumination intensity

If light guide portions are arranged on the rear surface side of emission portions, then local dimming is achieved, but light leakage to adjacent areas occurs causing halo formation

Engineering Contradiction:

Improvelocal dimming capabilityVSAvoidhalo formation

Core Design Contradiction:

Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The light guide film is divided into multiple independent light guide portions, each corresponding to a specific emission portion. This segmentation allows independent light control for each region, enabling local dimming while preventing light leakage to adjacent areas through precise light incidence control at each segmented portion.

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If the backlight unit is made flexible for curved surfaces, then adaptability is improved, but positional relationship between light guide portions and emission portions deviates under impact

Engineering Contradiction:

Improveflexibility for curved surfacesVSAvoidpositional relationship stability under impact

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent uses a flexible light guide film with light guide portions and emission portions arranged in the same plane. This flexible film structure allows the backlight unit to be bent for curved surfaces while maintaining the positional relationship between light guide portions and emission portions, preventing halo formation even under impact conditions.

Inventive Principle:

Principle #30Flexible shells and thin films

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 allows for a bendable and impact-resistant light guide film that effectively adjusts brightness and prevents halo formation, even when the backlight unit is bent, by ensuring proper light incidence and emission, thus enhancing the display's performance and power efficiency.

Implementation Method 1

the light guide portion guides light incident from a light source to the emission portion

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentUS11016240B2Light guide film and backlight unit

Publication Date: 2021.05.25 FUJIFILM CORP

AI summary

A light guide film that is bendable, has a strong resistance to impact, and can perform the adjustment of the brightness per region, and a backlight unit. The light guide film includes a plurality of optical units each of which includes a light guide portion and an emission portion; and a resin portion that is filled between the optical units adjacent to each other, in which the light guide portion guides light incident from a light source to the emission portion, the emission portion emits light guided and incident from the light guide portion from a light emission surface, the plurality of optical units are arranged in a plane direction of the light emission surfaces such that the light emission surfaces of the emission portions are parallel to each other, and the light guide portions and the emission portions are arranged in the plane direction of the light emission surfaces.