Backlight Module Light-Reflecting Plate Offset for Hotspot Reduction
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Solution Overview
Problem
Conventional LCD backlight modules using wedge-shaped light guide plates suffer from hotspot and light leakage phenomena, affecting image quality due to inefficient light distribution.
Innovation Solution
The proposed backlight module incorporates a wedge-shaped light guide plate with a light-reflecting plate and optional extended light-reflecting plate, light absorbing plate, or bezel, where the light-reflecting plate's position and shape are optimized to minimize hotspot and light leakage, maintaining good light guiding efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a wedge-shaped light guide plate is used to prevent lights from being emitted out of the light guide plate, then light guiding efficiency is enhanced, but hot spot phenomenon and light leakage phenomenon occur at locations corresponding to the light source
Solution Approach 1:
The patent extracts and removes the problematic reflected light paths by positioning the light-reflecting plate's end at specific offsets from the first boundary. This takes out the harmful reflection paths that cause hot spots and light leakage while preserving the useful light guiding function of the wedge-shaped structure.
Solution Approach 2:
The patent applies local quality by creating different functional zones: the light-reflecting plate is positioned with specific offsets (first offset ≤0.5mm or second offset ≥0.5mm) to create localized reflection zones that prevent hot spots at critical areas while maintaining overall light guiding efficiency in other regions.
2Loss of energy
If the light-reflecting plate is positioned closer to the light-incident surface, then more light is reflected back into the light guide plate, but hot spot phenomenon occurs
Solution Approach 1:
The patent changes the positional parameter of the light-reflecting plate by defining specific offset ranges (first offset ≤0.5mm or second offset ≥0.5mm from the first boundary). This parameter adjustment optimizes the balance between light reflection efficiency and prevention of hot spot phenomenon.
3Object-generated harmful factors
If the light-reflecting plate is positioned farther from the light-incident surface, then hot spot phenomenon is reduced, but light guiding efficiency decreases
Solution Approach 1:
The patent defines two offset ranges for the light-reflecting plate position: first offset ≤0.5mm for maximum light reflection, and second offset ≥0.5mm for reducing hot spots. These parameter changes allow optimization based on specific performance requirements while maintaining good light guiding efficiency.
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 design effectively reduces hotspot and light leakage issues, enhancing the display quality of LCDs by ensuring uniform light distribution and minimizing flux loss.
Implementation Method 1
the light reflecting plate will reflect the light R into the wedge-shaped light guide plate 10
Implementation Method 2
The light-reflecting plate has an end near the light-incident surface
Data Source
AI summary
A backlight module includes a light guide plate, at least one light source, and a light-reflecting plate. The light guide plate includes a light-emitting surface, a bottom surface, a light-incident surface, and a guiding tilt surface. One end of guiding tilt surface and light-emitting surface are intersected at a first boundary, and the other end connects to a top edge of light-incident surface. The guiding tilt surface extends toward a direction of protruding the light-emitting surface. The horizontal distance between the first boundary and light-incident surface is L. The light-reflecting plate is disposed under the bottom surface. When the horizontal distance d between light-incident surface and an end of light-reflecting plate near light-incident surface is less than L, the horizontal distance between a vertical projection of the end on light-emitting surface and first boundary is not more than 0.5 mm. When d is more than L, x is at least 0.5 mm.