Light Guide Plate Inclined Portion for LED Step-Difference
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Solution Overview
Problem
Liquid crystal display apparatuses suffer from light leakage and reduced brightness due to step-differences between light emitting diodes and light guide plates, which are not self-emissive and require a backlight assembly.
Innovation Solution
The design includes a light guide plate with an inclined portion to align with the light emitting diodes, eliminating the step-difference and enhancing light efficiency by guiding light effectively to the liquid crystal display panel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If light emitting diodes are directly mounted on the main flexible printed circuit, then device complexity is reduced and manufacturing cost is lowered, but step-difference between light emitting diodes and light guide plate causes light leakage and reduced brightness
Solution Approach 1:
The light guide plate transitions from a flat structure to a three-dimensional structure with an inclined portion. This dimensional change allows the light guide plate surface to match the mounting position of the light emitting diode, eliminating the step-difference problem while maintaining the simplified single-circuit-board structure.
Solution Approach 2:
The light guide plate is designed with a localized inclined portion only at the region where the light emitting diode is mounted, rather than changing the entire plate structure. This localized modification precisely addresses the step-difference issue at the LED mounting position while keeping the rest of the light guide plate simple and flat.
2Ease of manufacture
If light emitting diodes are directly mounted on the main flexible printed circuit, then manufacturing process is simplified by omitting soldering process, but light leakage occurs due to step-difference
Solution Approach 1:
By introducing an inclined portion that creates a gradual transition in height, the light guide plate eliminates the abrupt step-difference that causes light leakage. This dimensional modification allows light to be guided smoothly without escaping, while maintaining the simplified manufacturing process of direct LED mounting.
Solution Approach 2:
The mounting step-difference, which initially causes light leakage, is transformed into a beneficial inclined surface structure. This inclined portion now serves to guide light effectively from the LED to the display panel, converting the harmful step-difference into a useful light-guiding feature.
3Illumination intensity
If separate flexible printed circuit is used for light emitting diodes, then light guiding is improved, but device complexity increases and manufacturing cost rises
Solution Approach 1:
The patent merges the light emitting diode mounting function directly onto the main flexible printed circuit board, eliminating the need for a separate flexible circuit for LEDs. This consolidation reduces device complexity and manufacturing steps while the inclined light guide plate ensures proper light guidance is achieved.
Solution Approach 2:
The inclined portion of the light guide plate acts as an intermediary structure between the light emitting diode and the liquid crystal display panel. It mediates the light transmission process, ensuring efficient light guiding while accommodating the direct mounting configuration on the single circuit board.
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 configuration prevents light leakage and improves brightness, resulting in enhanced light efficiency and manufacturing cost reduction by eliminating the need for a separate flexible printed circuit board.
Implementation Method 1
a light guide plate disposed over the bottom chassis, the light guide plate including an incident surface and an inclined portion
Implementation Method 2
the light guide plate further including an opposite surface facing the incident surface, an exiting surface extended in a direction substantially perpendicular to the incident surface
Data Source
AI summary
A liquid crystal display apparatus includes a light guide plate, a bottom chassis, a liquid crystal display panel disposed on the light guide plate to display an image, a flexible printed circuit board connected to the liquid crystal display panel and outwardly bent toward a rear surface of the bottom chassis to be fixed to the rear surface, and at least one point light source disposed at an adjacent position to an incident surface of the light guide plate. The light guide plate includes an inclined portion from a lower side of the light guide plate toward an upper side of the light guide plate. Advantageously, the liquid crystal display apparatus may prevent the occurrence of the step-difference between the point light source and the light guide plate, thereby improving light efficiency and brightness.