Condensing Sheet Prism Segmentation for Side Lobe Reduction
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Solution Overview
Problem
Conventional condensing sheets in liquid crystal display devices suffer from side lobes that degrade light condensing efficiency, leading to reduced luminance and contrast ratio at viewing angles.
Innovation Solution
A condensing sheet with a base film featuring alternately defined areas of condensation patterns and flat surfaces, where the width of the condensation patterns is greater than the flat surface, and the height and angle of the patterns are optimized to minimize side lobes and enhance luminance at viewing angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional prism sheet condensing sheet is used, then light condensing efficiency is improved, but side lobes occur that degrade luminance and contrast ratio at viewing angles
Solution Approach 1:
The condensing sheet is segmented into multiple types of prisms (first prisms with larger cross-sectional area, second prisms with smaller cross-sectional area) arranged in different regions. This segmentation allows different parts of the sheet to handle light differently, reducing side lobes while maintaining condensing efficiency
Solution Approach 2:
Different regions of the condensing sheet have different prism characteristics tailored to local requirements. The first prisms with larger cross-sectional area are positioned in specific regions to optimize light condensing, while second prisms with smaller cross-sectional area are positioned in other regions to minimize side lobe effects, creating local quality variations that solve the overall problem
2Ease of manufacture
If the condensing sheet structure is simplified, then manufacturing ease is improved, but light condensing efficiency and viewing angle performance deteriorate
Solution Approach 1:
Instead of making the entire condensing sheet uniformly complex, only specific regions contain the more complex first prisms with larger cross-sectional area, while other regions use simpler second prisms. This partial application of complexity maintains manufacturing feasibility while achieving the required light condensing efficiency in critical areas
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 reduces side lobes and increases luminance at viewing angles, thereby enhancing the contrast ratio and improving image quality in liquid crystal display devices.
Implementation Method 1
The inclined light L2 incident upon the first and second inclined surfaces 5a and 5b of a prism at a predetermined angle is refracted at the first inclined surface 5a or the second inclined surface 5b of the prism and perpendicularly collected at a liquid crystal panel
Implementation Method 2
The perpendicular light L1 perpendicularly incident upon the rear surface of the condensing sheet 5 undergoes total reflection on the first and second inclined surfaces 5a and 5b of a prism, and is then recycled
Data Source
AI summary
A condensing sheet, a backlight unit and a liquid crystal display device using the same are disclosed. The condensing sheet includes a base film, and a plurality of condensation patterns formed on the base film, wherein a first area and a second area are alternately defined on an upper surface of the base film, at least two condensation patterns are arranged in the first area, and a flat surface is formed in the second area, and wherein a width of each of the condensation patterns may be greater than a width of the flat surface.