Circular Backlight with Fan-Shaped Segments for Uniform Illumination
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Solution Overview
Problem
Existing liquid crystal display devices experience uneven illumination due to non-intersecting light sources, leading to local dark spots when one light source malfunctions or wiring breaks, reducing overall brightness and display quality.
Innovation Solution
A lighting device with a circular or elliptical light guide plate and multiple fan-shaped areas, where light sources are arranged to intersect at the center, ensuring even light distribution and redundant power supply connections to prevent local dark spots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If light sources are arranged with non-intersecting output directions to avoid concentration of light, then uneven illumination is reduced, but when one light source malfunctions, local dark spots are generated due to lack of redundancy
Solution Approach 1:
The light guide plate is divided into multiple fan-shaped areas by segment lines extending from the center. Each fan-shaped area is assigned to specific light sources, creating independent illumination zones. This segmentation allows the system to maintain uniform illumination across the entire plate while enabling targeted compensation when individual light sources fail, as adjacent fan-shaped areas can compensate for localized failures.
Solution Approach 2:
Different regions of the light guide plate are assigned different functions through the fan-shaped area division. The segment lines create distinct zones where light from specific sources is directed. When a light source fails, the local quality of illumination in its designated fan-shaped area is maintained through the optical design that allows light redistribution, preventing dark spots while preserving the non-intersecting arrangement that ensures uniformity.
2Area of stationary object
If multiple light sources are arranged to surround the light guide plate, then overall illumination coverage is improved, but the complexity of wiring and power supply increases
Solution Approach 1:
The patent transitions from linear or grid-based light source arrangements to a circumferential arrangement around the light guide plate. Light sources are positioned along the perimeter, with their optical axes directed toward the center. This dimensional change allows comprehensive coverage of the entire light guide plate area while simplifying wiring, as power and control lines can be routed along the circumferential path, reducing the number of intersections and connection points required.
Solution Approach 2:
Multiple light sources are arranged in a continuous circumferential pattern around the light guide plate, merging their individual contributions into a unified illumination system. The fan-shaped areas created by segment lines from the center consolidate the light paths from different sources into distinct zones, allowing the system to achieve complete area coverage while managing wiring complexity through integrated power distribution along the circular arrangement.
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 ensures uniform brightness and high display quality by equalizing light output across the display panel, even if one light source fails or wiring breaks, maintaining image quality.
Implementation Method 1
a light guide plate configured to convert a light flux emitted by the light source into a planar light flux suitable for illumination of the liquid crystal panel
Data Source
AI summary
A backlight device (12) includes a light guide plate (14), and LEDs (17), and wiring portions (18c). The light guide plate (14) has a substantially circular outer shape and has fan-shaped areas (SA) defined by segment lines (SL) extending through a center (C) thereof. All the segment lines (SL) meet at the center (C). The LEDs (17) are arranged such that middle positions between LEDs (17) each located at an end in the circumferential direction in the respective sets of the LEDs (17) provided for the fan-shaped areas (SA) adjacent to each other in the circumferential direction coincides with the segment lines (SL). The wiring portions (18c) are equal or larger in number than the LEDs (17) included in each of the sets of LEDs (17) provided for the fan-shaped areas (SA) and are configured to supply electric power to the respective LEDs (17).