Light-Diffusing Member Groove Filling with Colored Particles
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Solution Overview
Problem
Rear-projection-type displays using total-reflection-type lenticular lens members often exhibit non-uniformity in stripes due to covering issues, which affect the transmittance and visibility of images, especially noticeable with single light sources like LCDs or DLPs, leading to decreased product yield and image quality.
Innovation Solution
A light-diffusing member with a diffusing-part base having grooves tapered towards the incident side, filled with a radiation-curing resin composition containing colored particles with a mean particle diameter of 3.5 μm to 20 μm, minimizing covering by reducing the slipping of particles between the doctor and the light-diffusing part, and using a ratio of small particles ≤7.0% by weight to prevent noticeable non-uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If small particle diameter colored particles are used in the resin composition, then the light-absorbing parts can be formed with finer detail, but the particles slip through the gap between the doctor and the light-diffusing part causing covering
Solution Approach 1:
The patent specifies a particle diameter range of 3.5 μm to 20 μm for colored particles, optimizing the balance between achieving sufficient light absorption and preventing particles from slipping through the doctor blade gap. This parameter optimization resolves the contradiction by finding the optimal particle size that provides both fine detail formation and adequate particle retention during the filling process.
2Productivity
If the resin composition is scraped off with a doctor into the grooves, then the grooves can be filled efficiently, but small particles slip through the gap causing covering on light-transmitting portions
Solution Approach 1:
The patent optimizes the particle diameter to 3.5 μm or more, which prevents particles from slipping through the gap between the doctor blade and the light-diffusing part during the scraping process. This maintains groove filling efficiency while eliminating the covering defect caused by particle leakage.
3Object-generated harmful factors
If colored particles with mean particle diameter of 3.5 μm or more are used, then covering is minimized, but the resin composition viscosity and particle distribution must be controlled
Solution Approach 1:
The patent specifies additional parameters including viscosity control (500-100,000 mPa·s at 25°C) and limits small particle content to 7.0% by weight or less. These multiple parameter specifications work together to prevent covering while maintaining manufacturability, resolving the contradiction by providing a comprehensive formulation guideline rather than a single parameter solution.
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
Significantly reduces non-uniformity in stripes on transmission type screens and rear-projection-type displays, enabling sharper image display with single light sources by preventing covering and maintaining high transmittance.
Implementation Method 1
filled with a radiation-curing resin composition containing colored particles
Implementation Method 2
the unit lens part—light-absorbing part interface totally reflects at least a part of incident light so as to diffuse transmitted light
Data Source
AI summary
The present invention provides a light-diffusing member having no non-uniformity in stripes. The light-diffusing member according to the present invention is for diffusing at least a part of transmitted light by totally reflecting the same. The light-diffusing member comprises a light-diffusing part that has a diffusing-part base having a plurality of grooves tapered down toward the incident side, formed on the light-outgoing side in juxtaposition with one another, and light-absorbing parts formed, in the grooves in the diffusing-part base, by a radiation-curing resin composition. The radiation-curing resin composition includes colored particles. The colored particles have a mean particle diameter of 3.5 μm or more and 20 μm or less.