Segmented Light Guide Plate for Precise Luminance Control
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Solution Overview
Problem
Existing liquid crystal display apparatuses face limitations in adjusting luminance due to the need for elongated light guide plates to diffuse point-light sources from LEDs, restricting the size of light guide blocks and preventing precise luminance adjustment in display regions.
Innovation Solution
The design incorporates a light guide plate with sectional surfaces and opening portions aligned with light emitting elements, allowing for efficient reflection and guidance of light, enabling uniform illumination even with shorter light guide regions and allowing for precise luminance control in minutely divided display areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If point-light source LEDs are used in the backlight, then the luminance can be adjusted locally, but the light guide plate must be elongated to diffuse the light uniformly, which restricts the size of light guide blocks and prevents precise luminance adjustment
Solution Approach 1:
The light guide plate is divided into multiple light guide blocks, each corresponding to a specific light emitting element. This segmentation allows independent control of luminance in different regions while using shorter light guide blocks instead of requiring a single elongated light guide plate.
Solution Approach 2:
Each light guide block is designed with specific local optical properties and dimensions tailored to its corresponding light emitting element. This allows optimized light diffusion characteristics for each region, achieving uniform illumination without requiring excessive length while maintaining precise luminance adjustment capability.
2Length of stationary object
If the light guide plate area is decreased to enable shorter light guide regions, then the optical path is reduced, but this makes it difficult to achieve uniform illumination from point-light sources
Solution Approach 1:
The patent changes the optical parameters by introducing microlens arrays and specific surface structures on the light guide blocks. These parameter changes enable effective light diffusion and uniform illumination distribution even with shorter light guide plate lengths, resolving the contradiction between compact size and illumination uniformity.
3Measurement precision
If multiple light guide blocks are used to enable precise luminance adjustment, then the device complexity increases, but this allows for better local dimming control
Solution Approach 1:
Multiple light guide blocks are merged into a single integrated backlight assembly with unified control electronics. This combining approach maintains the precise local dimming control capability of multiple blocks while simplifying the overall device structure and reducing operational complexity.
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 allows for effective uniform illumination and precise luminance adjustment in display regions, enabling improved contrast and image quality by reducing light loss and allowing for smaller, more flexible light guide block sizes.
Implementation Method 1
the side of the second principal surface of the light guide plate is also provided with second sectional surfaces, each of which is disposed adjacent to the first sectional surface so as to face obliquely to the first sectional surface and has a reflection surface for reflecting the light originated from each light emitting element toward the first sectional surface
Data Source
AI summary
An illuminating device includes light emitting elements extending in a lengthwise direction and a light guide plate having a first principal surface for emitting light from the light emitting elements and a second principal surface facing the first principal surface. The light guide plate has light guide regions corresponding to the light emitting elements. The light emitting elements overlap the light guide plate on a side of the second principal surface of the light guide plate in plan view. The side of the second principal surface of the light guide plate has first sectional surfaces, on which light originated from each of the light emitting elements is incident. The side of the second principal surface of the light guide plate has second sectional surfaces, each having a reflection surface for reflecting the light originated from each light emitting element toward the first sectional surface, corresponding to the light emitting elements.