Light Guide Plate Prismatic Density for Display Border Brightness
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Solution Overview
Problem
The challenge in designing display devices is to minimize the brightening effect along the bottom border due to the narrowing gap between the LED bar and the light guide plate, which traditional methods like using black mylar film have become less effective as the gap shrinks, leading to visible artifacts in the displayed image.
Innovation Solution
The implementation of a light guide plate with prismatic elements arranged in varying densities across its surface to control the brightness pattern, where a higher density of prismatic elements is used along the edges and a lower density in specific regions to achieve a uniform brightness distribution, including extending the brighter viewing area to the bottom of the display panel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the gap between the LED bar and the light guide plate is narrowed to reduce border width, then the display device achieves a narrower border, but the brightening effect along the bottom border increases due to light leakage
Solution Approach 1:
The light guide plate incorporates a light absorbing layer specifically positioned at the bottom surface where light leakage occurs. This local modification targets only the problematic region (bottom border area) without affecting other parts of the display, allowing the gap to be narrowed while preventing brightening artifacts through localized light absorption
Solution Approach 2:
A light absorbing layer is introduced as an intermediary element between the LED bar and the light guide plate at the bottom border region. This intermediate layer absorbs stray light that would otherwise leak and create brightening effects, enabling the narrowed gap design to function without the harmful brightening artifact
2Object-generated harmful factors
If traditional methods like black mylar film are used to reduce border brightening, then the brightening effect is reduced, but the method becomes less effective as the gap shrinks and visible artifacts remain
Solution Approach 1:
The invention transitions from using reflective black mylar film to a light absorbing layer with different optical parameters. The light absorbing layer has high light absorption capacity that remains effective even in narrowed gaps, changing the approach from reflection-based to absorption-based light control, thereby maintaining reliability across different gap sizes
Solution Approach 2:
The invention replaces the mechanical black mylar film solution with an integrated light absorbing layer within the light guide plate structure. This substitution provides more reliable brightening reduction because the light absorbing layer is inherently effective at absorbing stray light regardless of gap size, unlike the reflective mylar film whose effectiveness diminishes as the gap narrows
3Illumination intensity
If the density of prismatic elements is increased along the bottom edge to control light distribution, then the brightness uniformity is improved, but the manufacturing complexity increases
Solution Approach 1:
The light guide plate features a light absorbing layer positioned specifically at the bottom surface where brightness non-uniformity occurs. This localized approach addresses the brightness uniformity issue in the problematic region without requiring complex variable density prismatic patterns across the entire plate, thereby managing manufacturing complexity while achieving the desired optical effect
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
This approach effectively washes out the bright region along the bottom of the display panel, providing a more uniform brightness and reducing visible artifacts, enhancing the display's visual quality by maintaining a brighter viewing area without increasing the border width.
Implementation Method 1
a light guide plate arranged to receive the emitted light at a minor surface of the light guide plate
Implementation Method 2
The light guide plate may include prismatic elements configured to reemit the light out a first major surface of the light guide plate
Implementation Method 3
prismatic elements configured to reemit the light
Data Source
AI summary
A display device includes a light source arranged to emit light along a first edge of the display device, and aa light guide plate arranged go receive the emitted light at a minor surface of the light guide plate. The light guide plate includes prismatic elements configured to reemit the light out a first major surface of the light guide plate. A first region of the light guide plate has a first portion of the prismatic elements arranged in a first density to provide a first brightness of the reemitted light reemitted. A second region of the light guide plate has a second portion of the prismatic elements arranged in a second density to provide a second brightness of the reemitted light reemitted. The first region is provided substantially along a first edge of the first major surface, and the second region is provided along a second, a third, and a fourth edge of the first major surface. The first brightness is brighter than the second brightness.