Transverse Prismatic Optical Substrates for Brightness and Diffusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical substrates for LCDs face challenges in achieving effective brightness enhancement and diffusion while minimizing power consumption, thickness, and weight, often resulting in reduced brightness and increased manufacturing costs, along with issues like interference fringes and moiré patterns.
Innovation Solution
A diffused prism substrate with a structured prismatic surface and an opposing structured lenticular surface, featuring shallow-curved lens structures and isolated ripples, which collimate and diffuse light effectively, reducing undesired optical effects like wet-out, Newton's rings, and interference fringes without significantly reducing overall brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If traditional brightness enhancement films with longitudinal prismatic structures are used, then on-axis brightness is improved, but perceived brightness declines rapidly at viewing angles between 35 and 45 degrees due to sharp cutoff
Solution Approach 1:
The patent replaces traditional longitudinal prismatic structures with transverse prismatic structures where the cross-sectional shape varies along the length of the prisms. This curvature variation in the prism geometry allows light to be redirected over a wider angular range, preventing the sharp cutoff effect at 35-45 degrees while maintaining on-axis brightness enhancement.
Solution Approach 2:
The patent changes the geometric parameters of the prismatic structures by varying the cross-sectional shape along the prism length. This parameter variation enables the optical film to maintain effective light redirection across broader viewing angles while preserving on-axis luminance, thus resolving the contradiction between peak brightness and viewing angle range.
2Illumination intensity
If multiple optical films including diffuser films and brightness enhancement films are stacked, then light distribution and brightness are improved, but device thickness and weight increase
Solution Approach 1:
The patent combines the functions of diffuser films and brightness enhancement films into a single integrated optical film layer. This merging eliminates the need for separate stacked films, thereby reducing overall thickness and weight while maintaining both light diffusion and brightness enhancement capabilities through the transverse prismatic structure design.
Solution Approach 2:
The transverse prismatic optical film performs multiple functions simultaneously: it acts as both a brightness enhancement element and a light redistributing element. This multi-functionality replaces what traditionally required multiple separate films, reducing the optical stack thickness while achieving comparable or superior light distribution quality.
3Illumination intensity
If longitudinal prismatic structures are used to direct light along viewing axes, then on-axis brightness is enhanced, but interference fringes and moiré patterns appear in the display image
Solution Approach 1:
The patent uses transverse prismatic structures with varying cross-sectional shapes that create more gradual light redirection patterns. This curved geometric approach distributes light more evenly across viewing angles, reducing the formation of interference fringes and moiré patterns that occur with the sharper, more uniform longitudinal prismatic structures.
Solution Approach 2:
The patent introduces asymmetry in the prism geometry by varying the cross-sectional shape along the prism length. This asymmetric design disrupts the regular periodic patterns that cause interference and moiré effects, while still maintaining effective light redirection for brightness enhancement.
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 enhances luminance and diffusion, reduces optical defects, and minimizes moiré interference patterns, achieving improved brightness and display quality while maintaining low thickness and weight, and reducing manufacturing complexity.
Implementation Method 1
The optical substrate possesses a structured surface that enhances luminance or brightness by collimating light
Implementation Method 2
the structured surfaces provide both light collimation and light diffusion characteristics
Data Source
AI summary
This invention discloses a method of forming an uneven structure on a substrate. Use a hard tool to penetrate into a mold to cut a first trench and a second trench in an order on a surface of a mold, wherein the hard tool has a smoothly-curved shape such that the transverse width of each of the first trench and the second trench increases as the penetrating depth of the hard tool increases, wherein when each of the first trench and the second trench marches along a first direction, the penetrating depth of the hard tool is controlled by repeating moving the hard tool up and down to cut the mold such that the transverse width of each of the first trench and the second trench varies according to the controlled penetrating depth of the hard tool, wherein the first trench and the second trench completely overlap with each other with no space therebetween. Then, use the surface of the mold to emboss a thin film on a substrate.